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[rt] Update to 4.0.8-rt6 

svn path=/dists/sid/linux/; revision=22841
This commit is contained in:
Uwe Kleine-König 2015-07-22 18:42:19 +00:00
parent 1fcd372ae9
commit 2017c10b63
357 changed files with 1612 additions and 612 deletions
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6
debian/changelog vendored
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@ -1,3 +1,9 @@
linux (4.0.8-2) UNRELEASED; urgency=medium
* [rt] Update to 4.0.8-rt6
-- Uwe Kleine-König <uwe@kleine-koenig.org> Tue, 21 Jul 2015 23:19:12 +0200
linux (4.0.8-1) unstable; urgency=medium
* New upstream stable update:

2
debian/patches/features/all/rt/0001-arm64-Mark-PMU-interrupt-IRQF_NO_THREAD.patch vendored
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@ -2,7 +2,7 @@ From d118bf15da869e555f5cd1d6f491f6f4c1b9df93 Mon Sep 17 00:00:00 2001
From: Anders Roxell <anders.roxell@linaro.org>
Date: Mon, 27 Apr 2015 22:53:08 +0200
Subject: [PATCH 1/3] arm64: Mark PMU interrupt IRQF_NO_THREAD
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Mark the PMU interrupts as non-threadable, as is the case with
arch/arm: d9c3365 ARM: 7813/1: Mark pmu interupt IRQF_NO_THREAD

167
debian/patches/features/all/rt/0001-sched-Implement-lockless-wake-queues.patch vendored Normal file
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@ -0,0 +1,167 @@
From 1fb321e7971c26d03e20a7f8d3bacc654c6abc5f Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 1 May 2015 08:27:50 -0700
Subject: [PATCH 1/2] sched: Implement lockless wake-queues
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
This is useful for locking primitives that can effect multiple
wakeups per operation and want to avoid lock internal lock contention
by delaying the wakeups until we've released the lock internal locks.
Alternatively it can be used to avoid issuing multiple wakeups, and
thus save a few cycles, in packet processing. Queue all target tasks
and wakeup once you've processed all packets. That way you avoid
waking the target task multiple times if there were multiple packets
for the same task.
Properties of a wake_q are:
- Lockless, as queue head must reside on the stack.
- Being a queue, maintains wakeup order passed by the callers. This can
be important for otherwise, in scenarios where highly contended locks
could affect any reliance on lock fairness.
- A queued task cannot be added again until it is woken up.
This patch adds the needed infrastructure into the scheduler code
and uses the new wake_list to delay the futex wakeups until
after we've released the hash bucket locks.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[tweaks, adjustments, comments, etc.]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Mason <clm@fb.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: George Spelvin <linux@horizon.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1430494072-30283-2-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/linux/sched.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++
kernel/sched/core.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 92 insertions(+)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -907,6 +907,50 @@ enum cpu_idle_type {
#define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
/*
+ * Wake-queues are lists of tasks with a pending wakeup, whose
+ * callers have already marked the task as woken internally,
+ * and can thus carry on. A common use case is being able to
+ * do the wakeups once the corresponding user lock as been
+ * released.
+ *
+ * We hold reference to each task in the list across the wakeup,
+ * thus guaranteeing that the memory is still valid by the time
+ * the actual wakeups are performed in wake_up_q().
+ *
+ * One per task suffices, because there's never a need for a task to be
+ * in two wake queues simultaneously; it is forbidden to abandon a task
+ * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
+ * already in a wake queue, the wakeup will happen soon and the second
+ * waker can just skip it.
+ *
+ * The WAKE_Q macro declares and initializes the list head.
+ * wake_up_q() does NOT reinitialize the list; it's expected to be
+ * called near the end of a function, where the fact that the queue is
+ * not used again will be easy to see by inspection.
+ *
+ * Note that this can cause spurious wakeups. schedule() callers
+ * must ensure the call is done inside a loop, confirming that the
+ * wakeup condition has in fact occurred.
+ */
+struct wake_q_node {
+ struct wake_q_node *next;
+};
+
+struct wake_q_head {
+ struct wake_q_node *first;
+ struct wake_q_node **lastp;
+};
+
+#define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
+
+#define WAKE_Q(name) \
+ struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
+
+extern void wake_q_add(struct wake_q_head *head,
+ struct task_struct *task);
+extern void wake_up_q(struct wake_q_head *head);
+
+/*
* sched-domains (multiprocessor balancing) declarations:
*/
#ifdef CONFIG_SMP
@@ -1505,6 +1549,8 @@ struct task_struct {
/* Protection of the PI data structures: */
raw_spinlock_t pi_lock;
+ struct wake_q_node wake_q;
+
#ifdef CONFIG_RT_MUTEXES
/* PI waiters blocked on a rt_mutex held by this task */
struct rb_root pi_waiters;
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -538,6 +538,52 @@ static bool set_nr_if_polling(struct tas
#endif
#endif
+void wake_q_add(struct wake_q_head *head, struct task_struct *task)
+{
+ struct wake_q_node *node = &task->wake_q;
+
+ /*
+ * Atomically grab the task, if ->wake_q is !nil already it means
+ * its already queued (either by us or someone else) and will get the
+ * wakeup due to that.
+ *
+ * This cmpxchg() implies a full barrier, which pairs with the write
+ * barrier implied by the wakeup in wake_up_list().
+ */
+ if (cmpxchg(&node->next, NULL, WAKE_Q_TAIL))
+ return;
+
+ get_task_struct(task);
+
+ /*
+ * The head is context local, there can be no concurrency.
+ */
+ *head->lastp = node;
+ head->lastp = &node->next;
+}
+
+void wake_up_q(struct wake_q_head *head)
+{
+ struct wake_q_node *node = head->first;
+
+ while (node != WAKE_Q_TAIL) {
+ struct task_struct *task;
+
+ task = container_of(node, struct task_struct, wake_q);
+ BUG_ON(!task);
+ /* task can safely be re-inserted now */
+ node = node->next;
+ task->wake_q.next = NULL;
+
+ /*
+ * wake_up_process() implies a wmb() to pair with the queueing
+ * in wake_q_add() so as not to miss wakeups.
+ */
+ wake_up_process(task);
+ put_task_struct(task);
+ }
+}
+
/*
* resched_curr - mark rq's current task 'to be rescheduled now'.
*

2
debian/patches/features/all/rt/0001-sparc64-use-generic-rwsem-spinlocks-rt.patch vendored
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@ -2,7 +2,7 @@ From d6a6675d436897cd1b09e299436df3499abd753e Mon Sep 17 00:00:00 2001
From: Allen Pais <allen.pais@oracle.com>
Date: Fri, 13 Dec 2013 09:44:41 +0530
Subject: [PATCH 1/3] sparc64: use generic rwsem spinlocks rt
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Allen Pais <allen.pais@oracle.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

2
debian/patches/features/all/rt/0001-uaccess-count-pagefault_disable-levels-in-pagefault_.patch vendored
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@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:06 +0200
Subject: [PATCH 01/14] uaccess: count pagefault_disable() levels in
pagefault_disabled
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Until now, pagefault_disable()/pagefault_enabled() used the preempt
count to track whether in an environment with pagefaults disabled (can

2
debian/patches/features/all/rt/0002-arm64-Allow-forced-irq-threading.patch vendored
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@ -2,7 +2,7 @@ From d76d3ed5cc944776ea2d42e5d49af58a86402f12 Mon Sep 17 00:00:00 2001
From: Anders Roxell <anders.roxell@linaro.org>
Date: Mon, 27 Apr 2015 22:53:09 +0200
Subject: [PATCH 2/3] arm64: Allow forced irq threading
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Now its safe to allow forced interrupt threading for arm64,
all timer interrupts and the perf interrupt are marked NO_THREAD, as is

182
debian/patches/features/all/rt/0002-futex-Implement-lockless-wakeups.patch vendored Normal file
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@ -0,0 +1,182 @@
From 783ec42143b22999b03f228d5658207136c1d945 Mon Sep 17 00:00:00 2001
From: Davidlohr Bueso <dave@stgolabs.net>
Date: Fri, 1 May 2015 08:27:51 -0700
Subject: [PATCH 2/2] futex: Implement lockless wakeups
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Given the overall futex architecture, any chance of reducing
hb->lock contention is welcome. In this particular case, using
wake-queues to enable lockless wakeups addresses very much real
world performance concerns, even cases of soft-lockups in cases
of large amounts of blocked tasks (which is not hard to find in
large boxes, using but just a handful of futex).
At the lowest level, this patch can reduce latency of a single thread
attempting to acquire hb->lock in highly contended scenarios by a
up to 2x. At lower counts of nr_wake there are no regressions,
confirming, of course, that the wake_q handling overhead is practically
non existent. For instance, while a fair amount of variation,
the extended pef-bench wakeup benchmark shows for a 20 core machine
the following avg per-thread time to wakeup its share of tasks:
nr_thr ms-before ms-after
16 0.0590 0.0215
32 0.0396 0.0220
48 0.0417 0.0182
64 0.0536 0.0236
80 0.0414 0.0097
96 0.0672 0.0152
Naturally, this can cause spurious wakeups. However there is no core code
that cannot handle them afaict, and furthermore tglx does have the point
that other events can already trigger them anyway.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Mason <clm@fb.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: George Spelvin <linux@horizon.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1430494072-30283-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/futex.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1090,9 +1090,11 @@ static void __unqueue_futex(struct futex
/*
* The hash bucket lock must be held when this is called.
- * Afterwards, the futex_q must not be accessed.
+ * Afterwards, the futex_q must not be accessed. Callers
+ * must ensure to later call wake_up_q() for the actual
+ * wakeups to occur.
*/
-static void wake_futex(struct futex_q *q)
+static void mark_wake_futex(struct wake_q_head *wake_q, struct futex_q *q)
{
struct task_struct *p = q->task;
@@ -1100,14 +1102,10 @@ static void wake_futex(struct futex_q *q
return;
/*
- * We set q->lock_ptr = NULL _before_ we wake up the task. If
- * a non-futex wake up happens on another CPU then the task
- * might exit and p would dereference a non-existing task
- * struct. Prevent this by holding a reference on p across the
- * wake up.
+ * Queue the task for later wakeup for after we've released
+ * the hb->lock. wake_q_add() grabs reference to p.
*/
- get_task_struct(p);
-
+ wake_q_add(wake_q, p);
__unqueue_futex(q);
/*
* The waiting task can free the futex_q as soon as
@@ -1117,9 +1115,6 @@ static void wake_futex(struct futex_q *q
*/
smp_wmb();
q->lock_ptr = NULL;
-
- wake_up_state(p, TASK_NORMAL);
- put_task_struct(p);
}
static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
@@ -1217,6 +1212,7 @@ futex_wake(u32 __user *uaddr, unsigned i
struct futex_q *this, *next;
union futex_key key = FUTEX_KEY_INIT;
int ret;
+ WAKE_Q(wake_q);
if (!bitset)
return -EINVAL;
@@ -1244,13 +1240,14 @@ futex_wake(u32 __user *uaddr, unsigned i
if (!(this->bitset & bitset))
continue;
- wake_futex(this);
+ mark_wake_futex(&wake_q, this);
if (++ret >= nr_wake)
break;
}
}
spin_unlock(&hb->lock);
+ wake_up_q(&wake_q);
out_put_key:
put_futex_key(&key);
out:
@@ -1269,6 +1266,7 @@ futex_wake_op(u32 __user *uaddr1, unsign
struct futex_hash_bucket *hb1, *hb2;
struct futex_q *this, *next;
int ret, op_ret;
+ WAKE_Q(wake_q);
retry:
ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, VERIFY_READ);
@@ -1320,7 +1318,7 @@ futex_wake_op(u32 __user *uaddr1, unsign
ret = -EINVAL;
goto out_unlock;
}
- wake_futex(this);
+ mark_wake_futex(&wake_q, this);
if (++ret >= nr_wake)
break;
}
@@ -1334,7 +1332,7 @@ futex_wake_op(u32 __user *uaddr1, unsign
ret = -EINVAL;
goto out_unlock;
}
- wake_futex(this);
+ mark_wake_futex(&wake_q, this);
if (++op_ret >= nr_wake2)
break;
}
@@ -1344,6 +1342,7 @@ futex_wake_op(u32 __user *uaddr1, unsign
out_unlock:
double_unlock_hb(hb1, hb2);
+ wake_up_q(&wake_q);
out_put_keys:
put_futex_key(&key2);
out_put_key1:
@@ -1503,6 +1502,7 @@ static int futex_requeue(u32 __user *uad
struct futex_pi_state *pi_state = NULL;
struct futex_hash_bucket *hb1, *hb2;
struct futex_q *this, *next;
+ WAKE_Q(wake_q);
if (requeue_pi) {
/*
@@ -1679,7 +1679,7 @@ static int futex_requeue(u32 __user *uad
* woken by futex_unlock_pi().
*/
if (++task_count <= nr_wake && !requeue_pi) {
- wake_futex(this);
+ mark_wake_futex(&wake_q, this);
continue;
}
@@ -1719,6 +1719,7 @@ static int futex_requeue(u32 __user *uad
out_unlock:
free_pi_state(pi_state);
double_unlock_hb(hb1, hb2);
+ wake_up_q(&wake_q);
hb_waiters_dec(hb2);
/*

2
debian/patches/features/all/rt/0002-kernel-SRCU-provide-a-static-initializer.patch vendored
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@ -1,7 +1,7 @@
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Tue, 19 Mar 2013 14:44:30 +0100
Subject: [PATCH] kernel/SRCU: provide a static initializer
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
There are macros for static initializer for the three out of four
possible notifier types, that are:

2
debian/patches/features/all/rt/0002-mm-uaccess-trigger-might_sleep-in-might_fault-with-d.patch vendored
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@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:07 +0200
Subject: [PATCH 02/14] mm, uaccess: trigger might_sleep() in might_fault()
with disabled pagefaults
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Commit 662bbcb2747c ("mm, sched: Allow uaccess in atomic with
pagefault_disable()") removed might_sleep() checks for all user access

2
debian/patches/features/all/rt/0002-x86-highmem-add-a-already-used-pte-check.patch vendored
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@ -2,7 +2,7 @@ From 65513f34449eedb6b84c24a3583266534c1627e4 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 11 Mar 2013 17:09:55 +0100
Subject: [PATCH 2/6] x86/highmem: add a "already used pte" check
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
This is a copy from kmap_atomic_prot().

2
debian/patches/features/all/rt/0003-arm-highmem-flush-tlb-on-unmap.patch vendored
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@ -2,7 +2,7 @@ From e2ca4d092d9c6e6b07b465b4d81da207bbcc7437 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 11 Mar 2013 21:37:27 +0100
Subject: [PATCH 3/6] arm/highmem: flush tlb on unmap
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The tlb should be flushed on unmap and thus make the mapping entry
invalid. This is only done in the non-debug case which does not look

2
debian/patches/features/all/rt/0003-uaccess-clarify-that-uaccess-may-only-sleep-if-pagef.patch vendored
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@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:08 +0200
Subject: [PATCH 03/14] uaccess: clarify that uaccess may only sleep if
pagefaults are enabled
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
In general, non-atomic variants of user access functions must not sleep
if pagefaults are disabled.

184
debian/patches/features/all/rt/0004-ipc-mqueue-Implement-lockless-pipelined-wakeups.patch vendored Normal file
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@ -0,0 +1,184 @@
From fa6004ad4528153b699a4d5ce5ea6b33acce74cc Mon Sep 17 00:00:00 2001
From: Davidlohr Bueso <dave@stgolabs.net>
Date: Mon, 4 May 2015 07:02:46 -0700
Subject: [PATCH 4/4] ipc/mqueue: Implement lockless pipelined wakeups
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
This patch moves the wakeup_process() invocation so it is not done under
the info->lock by making use of a lockless wake_q. With this change, the
waiter is woken up once it is STATE_READY and it does not need to loop
on SMP if it is still in STATE_PENDING. In the timeout case we still need
to grab the info->lock to verify the state.
This change should also avoid the introduction of preempt_disable() in -rt
which avoids a busy-loop which pools for the STATE_PENDING -> STATE_READY
change if the waiter has a higher priority compared to the waker.
Additionally, this patch micro-optimizes wq_sleep by using the cheaper
cousin of set_current_state(TASK_INTERRUPTABLE) as we will block no
matter what, thus get rid of the implied barrier.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: George Spelvin <linux@horizon.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Mason <clm@fb.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/1430748166.1940.17.camel@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
ipc/mqueue.c | 54 +++++++++++++++++++++++++++++++++---------------------
1 file changed, 33 insertions(+), 21 deletions(-)
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -47,8 +47,7 @@
#define RECV 1
#define STATE_NONE 0
-#define STATE_PENDING 1
-#define STATE_READY 2
+#define STATE_READY 1
struct posix_msg_tree_node {
struct rb_node rb_node;
@@ -571,15 +570,12 @@ static int wq_sleep(struct mqueue_inode_
wq_add(info, sr, ewp);
for (;;) {
- set_current_state(TASK_INTERRUPTIBLE);
+ __set_current_state(TASK_INTERRUPTIBLE);
spin_unlock(&info->lock);
time = schedule_hrtimeout_range_clock(timeout, 0,
HRTIMER_MODE_ABS, CLOCK_REALTIME);
- while (ewp->state == STATE_PENDING)
- cpu_relax();
-
if (ewp->state == STATE_READY) {
retval = 0;
goto out;
@@ -907,11 +903,15 @@ SYSCALL_DEFINE1(mq_unlink, const char __
* list of waiting receivers. A sender checks that list before adding the new
* message into the message array. If there is a waiting receiver, then it
* bypasses the message array and directly hands the message over to the
- * receiver.
- * The receiver accepts the message and returns without grabbing the queue
- * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
- * are necessary. The same algorithm is used for sysv semaphores, see
- * ipc/sem.c for more details.
+ * receiver. The receiver accepts the message and returns without grabbing the
+ * queue spinlock:
+ *
+ * - Set pointer to message.
+ * - Queue the receiver task for later wakeup (without the info->lock).
+ * - Update its state to STATE_READY. Now the receiver can continue.
+ * - Wake up the process after the lock is dropped. Should the process wake up
+ * before this wakeup (due to a timeout or a signal) it will either see
+ * STATE_READY and continue or acquire the lock to check the state again.
*
* The same algorithm is used for senders.
*/
@@ -919,21 +919,29 @@ SYSCALL_DEFINE1(mq_unlink, const char __
/* pipelined_send() - send a message directly to the task waiting in
* sys_mq_timedreceive() (without inserting message into a queue).
*/
-static inline void pipelined_send(struct mqueue_inode_info *info,
+static inline void pipelined_send(struct wake_q_head *wake_q,
+ struct mqueue_inode_info *info,
struct msg_msg *message,
struct ext_wait_queue *receiver)
{
receiver->msg = message;
list_del(&receiver->list);
- receiver->state = STATE_PENDING;
- wake_up_process(receiver->task);
- smp_wmb();
+ wake_q_add(wake_q, receiver->task);
+ /*
+ * Rely on the implicit cmpxchg barrier from wake_q_add such
+ * that we can ensure that updating receiver->state is the last
+ * write operation: As once set, the receiver can continue,
+ * and if we don't have the reference count from the wake_q,
+ * yet, at that point we can later have a use-after-free
+ * condition and bogus wakeup.
+ */
receiver->state = STATE_READY;
}
/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
* gets its message and put to the queue (we have one free place for sure). */
-static inline void pipelined_receive(struct mqueue_inode_info *info)
+static inline void pipelined_receive(struct wake_q_head *wake_q,
+ struct mqueue_inode_info *info)
{
struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
@@ -944,10 +952,9 @@ static inline void pipelined_receive(str
}
if (msg_insert(sender->msg, info))
return;
+
list_del(&sender->list);
- sender->state = STATE_PENDING;
- wake_up_process(sender->task);
- smp_wmb();
+ wake_q_add(wake_q, sender->task);
sender->state = STATE_READY;
}
@@ -965,6 +972,7 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqd
struct timespec ts;
struct posix_msg_tree_node *new_leaf = NULL;
int ret = 0;
+ WAKE_Q(wake_q);
if (u_abs_timeout) {
int res = prepare_timeout(u_abs_timeout, &expires, &ts);
@@ -1049,7 +1057,7 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqd
} else {
receiver = wq_get_first_waiter(info, RECV);
if (receiver) {
- pipelined_send(info, msg_ptr, receiver);
+ pipelined_send(&wake_q, info, msg_ptr, receiver);
} else {
/* adds message to the queue */
ret = msg_insert(msg_ptr, info);
@@ -1062,6 +1070,7 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqd
}
out_unlock:
spin_unlock(&info->lock);
+ wake_up_q(&wake_q);
out_free:
if (ret)
free_msg(msg_ptr);
@@ -1149,14 +1158,17 @@ SYSCALL_DEFINE5(mq_timedreceive, mqd_t,
msg_ptr = wait.msg;
}
} else {
+ WAKE_Q(wake_q);
+
msg_ptr = msg_get(info);
inode->i_atime = inode->i_mtime = inode->i_ctime =
CURRENT_TIME;
/* There is now free space in queue. */
- pipelined_receive(info);
+ pipelined_receive(&wake_q, info);
spin_unlock(&info->lock);
+ wake_up_q(&wake_q);
ret = 0;
}
if (ret == 0) {

2
debian/patches/features/all/rt/0004-mm-explicitly-disable-enable-preemption-in-kmap_atom.patch vendored
View File

@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:09 +0200
Subject: [PATCH 04/14] mm: explicitly disable/enable preemption in
kmap_atomic_*
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The existing code relies on pagefault_disable() implicitly disabling
preemption, so that no schedule will happen between kmap_atomic() and

2
debian/patches/features/all/rt/0005-futex-Ensure-lock-unlock-symetry-versus-pi_lock-and-.patch vendored
View File

@ -3,7 +3,7 @@ From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 1 Mar 2013 11:17:42 +0100
Subject: [PATCH 5/6] futex: Ensure lock/unlock symetry versus pi_lock and
hash bucket lock
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
In exit_pi_state_list() we have the following locking construct:

2
debian/patches/features/all/rt/0005-mips-kmap_coherent-relies-on-disabled-preemption.patch vendored
View File

@ -2,7 +2,7 @@ From 91021aa7ea1469d0b3127e68d177e0ad58a7eda3 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:10 +0200
Subject: [PATCH 05/14] mips: kmap_coherent relies on disabled preemption
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
k(un)map_coherent relies on pagefault_disable() to also disable
preemption.

2
debian/patches/features/all/rt/0006-mm-use-pagefault_disable-to-check-for-disabled-pagef.patch vendored
View File

@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:11 +0200
Subject: [PATCH 06/14] mm: use pagefault_disable() to check for disabled
pagefaults in the handler
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Introduce faulthandler_disabled() and use it to check for irq context and
disabled pagefaults (via pagefault_disable()) in the pagefault handlers.

2
debian/patches/features/all/rt/0007-drm-i915-use-pagefault_disabled-to-check-for-disable.patch vendored
View File

@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:12 +0200
Subject: [PATCH 07/14] drm/i915: use pagefault_disabled() to check for
disabled pagefaults
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Now that the pagefault disabled counter is in place, we can replace
the in_atomic() check by a pagefault_disabled() checks.

2
debian/patches/features/all/rt/0008-futex-UP-futex_atomic_op_inuser-relies-on-disabled-p.patch vendored
View File

@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:13 +0200
Subject: [PATCH 08/14] futex: UP futex_atomic_op_inuser() relies on disabled
preemption
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Let's explicitly disable/enable preemption in the !CONFIG_SMP version
of futex_atomic_op_inuser, to prepare for pagefault_disable() not

2
debian/patches/features/all/rt/0009-futex-UP-futex_atomic_cmpxchg_inatomic-relies-on-dis.patch vendored
View File

@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:14 +0200
Subject: [PATCH 09/14] futex: UP futex_atomic_cmpxchg_inatomic() relies on
disabled preemption
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Let's explicitly disable/enable preemption in the !CONFIG_SMP version
of futex_atomic_cmpxchg_inatomic, to prepare for pagefault_disable() not

2
debian/patches/features/all/rt/0010-arm-futex-UP-futex_atomic_cmpxchg_inatomic-relies-on.patch vendored
View File

@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:15 +0200
Subject: [PATCH 10/14] arm/futex: UP futex_atomic_cmpxchg_inatomic() relies on
disabled preemption
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The !CONFIG_SMP implementation of futex_atomic_cmpxchg_inatomic()
requires preemption to be disabled to guarantee mutual exclusion.

2
debian/patches/features/all/rt/0011-arm-futex-UP-futex_atomic_op_inuser-relies-on-disabl.patch vendored
View File

@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:16 +0200
Subject: [PATCH 11/14] arm/futex: UP futex_atomic_op_inuser() relies on
disabled preemption
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The !CONFIG_SMP implementation of futex_atomic_op_inuser() seems to rely
on disabled preemption to guarantee mutual exclusion.

2
debian/patches/features/all/rt/0012-futex-clarify-that-preemption-doesn-t-have-to-be-dis.patch vendored
View File

@ -3,7 +3,7 @@ From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:17 +0200
Subject: [PATCH 12/14] futex: clarify that preemption doesn't have to be
disabled
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
As arm64 and arc have no special implementations for !CONFIG_SMP, mutual
exclusion doesn't seem to rely on preemption.

2
debian/patches/features/all/rt/0013-mips-properly-lock-access-to-the-fpu.patch vendored
View File

@ -2,7 +2,7 @@ From 66ba6c9e2893bd2f7659286627b05c37312994db Mon Sep 17 00:00:00 2001
From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:19 +0200
Subject: [PATCH 13/14] mips: properly lock access to the fpu
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Let's always disable preemption and pagefaults when locking the fpu,
so we can be sure that the owner won't change in between.

2
debian/patches/features/all/rt/0014-uaccess-decouple-preemption-from-the-pagefault-logic.patch vendored
View File

@ -2,7 +2,7 @@ From 573a49b98c80acdeb8f2b0e3990863a30900c2f7 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 11 May 2015 17:52:20 +0200
Subject: [PATCH 14/14] uaccess: decouple preemption from the pagefault logic
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
As the fault handlers now all rely on the pagefault_disabled() checks
and implicit preempt_disable() calls by pagefault_disable() have been

2
debian/patches/features/all/rt/API-cleanup-use-local_lock-not-__local_lock-for-soft.patch vendored
View File

@ -2,7 +2,7 @@ From 116a588e1e4b108bfd01b5ae8de602c12aec3323 Mon Sep 17 00:00:00 2001
From: Nicholas Mc Guire <der.herr@hofr.at>
Date: Fri, 17 Jan 2014 20:44:03 +0100
Subject: [PATCH 7/7] API cleanup - use local_lock not __local_lock for soft
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
trivial API cleanup - kernel/softirq.c was mimiking local_lock.

2
debian/patches/features/all/rt/ARM-cmpxchg-define-__HAVE_ARCH_CMPXCHG-for-armv6-and.patch vendored
View File

@ -3,7 +3,7 @@ From: Yong Zhang <yong.zhang at windriver.com>
Date: Thu, 29 Jan 2015 12:56:18 -0600
Subject: [PATCH] ARM: cmpxchg: define __HAVE_ARCH_CMPXCHG for armv6 and
later
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Both pi_stress and sigwaittest in rt-test show performance gain with
__HAVE_ARCH_CMPXCHG. Testing result on coretile_express_a9x4:

2
debian/patches/features/all/rt/ARM-enable-irq-in-translation-section-permission-fau.patch vendored
View File

@ -6,7 +6,7 @@ Subject: [PATCH] ARM: enable irq in translation/section permission fault
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Probably happens on all ARM, with
CONFIG_PREEMPT_RT_FULL

2
debian/patches/features/all/rt/ASoC-Intel-sst-use-instead-of-at-the-of-a-C-statemen.patch vendored
View File

@ -2,7 +2,7 @@ From f407a2e976855eb4553d950f124c196061bbbd6c Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 11 Jun 2015 14:17:06 +0200
Subject: [PATCH] ASoC: Intel: sst: use ; instead of , at the of a C statement
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
This was spotted by Fernando Lopez-Lezcano <nando@ccrma.Stanford.EDU>
while he tried to compile a -RT kernel with this driver enabled.

2
debian/patches/features/all/rt/HACK-printk-drop-the-logbuf_lock-more-often.patch vendored
View File

@ -2,7 +2,7 @@ From b72b514282ffad0d665ea94932b968f388304079 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 21 Mar 2013 19:01:05 +0100
Subject: [PATCH] HACK: printk: drop the logbuf_lock more often
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The lock is hold with irgs off. The latency drops 500us+ on my arm bugs
with a "full" buffer after executing "dmesg" on the shell.

2
debian/patches/features/all/rt/KVM-lapic-mark-LAPIC-timer-handler-as-irqsafe.patch vendored
View File

@ -2,7 +2,7 @@ From d24c954fa7a252b093fa8ba9ed12c00bc3829bbe Mon Sep 17 00:00:00 2001
From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Wed, 8 Apr 2015 20:33:25 -0300
Subject: [PATCH 2/2] KVM: lapic: mark LAPIC timer handler as irqsafe
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Since lapic timer handler only wakes up a simple waitqueue,
it can be executed from hardirq context.

2
debian/patches/features/all/rt/KVM-use-simple-waitqueue-for-vcpu-wq.patch vendored
View File

@ -2,7 +2,7 @@ From 73a22bd9fee012b115222b6b20b42fd8f581a089 Mon Sep 17 00:00:00 2001
From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Wed, 8 Apr 2015 20:33:24 -0300
Subject: [PATCH 1/2] KVM: use simple waitqueue for vcpu->wq
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The problem:

2
debian/patches/features/all/rt/Revert-migrate_disable-pushd-down-in-atomic_dec_and_.patch vendored
View File

@ -3,7 +3,7 @@ From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 2 May 2014 17:32:30 +0200
Subject: [PATCH] Revert "migrate_disable pushd down in
atomic_dec_and_spin_lock"
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
This reverts commit ff9c870c3e27d58c9512fad122e91436681fee5a.
Cc: stable-rt@vger.kernel.org

2
debian/patches/features/all/rt/Revert-rwsem-rt-Do-not-allow-readers-to-nest.patch vendored
View File

@ -2,7 +2,7 @@ From 1db4ce56001465fba240916d0c8de7443cafec62 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 25 Feb 2015 12:16:43 +0100
Subject: [PATCH] Revert "rwsem-rt: Do not allow readers to nest"
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
This behaviour is required by cpufreq and its logic is "okay": It does a
read_lock followed by a try_read_lock.

49
debian/patches/features/all/rt/Revert-slub-delay-ctor-until-the-object-is-requested.patch vendored Normal file
View File

@ -0,0 +1,49 @@
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 13 Jul 2015 13:08:25 +0200
Subject: Revert "slub: delay ctor until the object is requested"
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
This approach is broken with SLAB_DESTROY_BY_RCU allocations.
Reported by Steven Rostedt and Koehrer Mathias.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
mm/slub.c | 9 ---------
1 file changed, 9 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index ea83736be12c..6d7f5165a634 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1411,13 +1411,11 @@ static void setup_object(struct kmem_cache *s, struct page *page,
void *object)
{
setup_object_debug(s, page, object);
-#ifndef CONFIG_PREEMPT_RT_FULL
if (unlikely(s->ctor)) {
kasan_unpoison_object_data(s, object);
s->ctor(object);
kasan_poison_object_data(s, object);
}
-#endif
}
static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
@@ -2562,13 +2560,6 @@ static __always_inline void *slab_alloc_node(struct kmem_cache *s,
if (unlikely(gfpflags & __GFP_ZERO) && object)
memset(object, 0, s->object_size);
-#ifdef CONFIG_PREEMPT_RT_FULL
- if (unlikely(s->ctor) && object) {
- kasan_unpoison_object_data(s, object);
- s->ctor(object);
- kasan_poison_object_data(s, object);
- }
-#endif
slab_post_alloc_hook(s, gfpflags, object);
--
2.1.4

2
debian/patches/features/all/rt/Revert-timers-do-not-raise-softirq-unconditionally.patch vendored
View File

@ -5,7 +5,7 @@ Subject: [PATCH] Revert "timers: do not raise softirq unconditionally"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The patch I revert here triggers the HRtimer switch from hardirq instead
of from softirq. As a result we get a periodic interrupt before the

2
debian/patches/features/all/rt/acpi-rt-Convert-acpi_gbl_hardware-lock-back-to-a-raw.patch vendored
View File

@ -1,7 +1,7 @@
From: Steven Rostedt <rostedt@goodmis.org>
Date: Wed, 13 Feb 2013 09:26:05 -0500
Subject: [PATCH] acpi/rt: Convert acpi_gbl_hardware lock back to a raw_spinlock_t
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
We hit the following bug with 3.6-rt:

6
debian/patches/features/all/rt/allow-preemption-in-recursive-migrate_disable-call.patch vendored
View File

@ -2,7 +2,7 @@ From 155cf657f6ddcade424253eb58d03a170dc9f64f Mon Sep 17 00:00:00 2001
From: Nicholas Mc Guire <der.herr@hofr.at>
Date: Wed, 20 Nov 2013 07:22:09 +0800
Subject: [PATCH 1/2] allow preemption in recursive migrate_disable call
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Minor cleanup in migrate_disable/migrate_enable. The recursive case
does not need to disable preemption as it is "pinned" to the current
@ -16,7 +16,7 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2757,13 +2757,12 @@ void migrate_disable(void)
@@ -2803,13 +2803,12 @@ void migrate_disable(void)
WARN_ON_ONCE(p->migrate_disable_atomic);
#endif
@ -31,7 +31,7 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
pin_current_cpu();
p->migrate_disable = 1;
preempt_enable();
@@ -2789,13 +2788,12 @@ void migrate_enable(void)
@@ -2835,13 +2834,12 @@ void migrate_enable(void)
#endif
WARN_ON_ONCE(p->migrate_disable <= 0);

2
debian/patches/features/all/rt/arch-arm64-Add-lazy-preempt-support.patch vendored
View File

@ -2,7 +2,7 @@ From 7400b8761276c4b41581abc39ecd587f51856398 Mon Sep 17 00:00:00 2001
From: Anders Roxell <anders.roxell@linaro.org>
Date: Thu, 14 May 2015 17:52:17 +0200
Subject: [PATCH 3/3] arch/arm64: Add lazy preempt support
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
arm64 is missing support for PREEMPT_RT. The main feature which is
lacking is support for lazy preemption. The arch-specific entry code,

2
debian/patches/features/all/rt/arm-at91-pit-remove-irq-handler-when-clock-is-unused.patch vendored
View File

@ -1,7 +1,7 @@
From: Benedikt Spranger <b.spranger@linutronix.de>
Date: Sat, 6 Mar 2010 17:47:10 +0100
Subject: ARM: AT91: PIT: Remove irq handler when clock event is unused
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Setup and remove the interrupt handler in clock event mode selection.
This avoids calling the (shared) interrupt handler when the device is

2
debian/patches/features/all/rt/arm-at91-tclib-default-to-tclib-timer-for-rt.patch vendored
View File

@ -1,7 +1,7 @@
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sat, 1 May 2010 18:29:35 +0200
Subject: ARM: at91: tclib: Default to tclib timer for RT
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
RT is not too happy about the shared timer interrupt in AT91
devices. Default to tclib timer for RT.

2
debian/patches/features/all/rt/arm-convert-boot-lock-to-raw.patch vendored
View File

@ -1,7 +1,7 @@
From: Frank Rowand <frank.rowand@am.sony.com>
Date: Mon, 19 Sep 2011 14:51:14 -0700
Subject: [PATCH] preempt-rt: Convert arm boot_lock to raw
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The arm boot_lock is used by the secondary processor startup code. The locking
task is the idle thread, which has idle->sched_class == &idle_sched_class.

2
debian/patches/features/all/rt/arm-disable-highmem-on-rt.patch vendored
View File

@ -1,7 +1,7 @@
Subject: arm-disable-highmem-on-rt.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 18 Jul 2011 17:09:28 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/arm-enable-highmem-for-rt.patch vendored
View File

@ -1,7 +1,7 @@
Subject: arm-enable-highmem-for-rt.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 13 Feb 2013 11:03:11 +0100
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/arm-preempt-lazy-support.patch vendored
View File

@ -1,7 +1,7 @@
Subject: arm-preempt-lazy-support.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 31 Oct 2012 12:04:11 +0100
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/arm-unwind-use_raw_lock.patch vendored
View File

@ -5,7 +5,7 @@ Subject: [PATCH RT] arm/unwind: use a raw_spin_lock
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Mostly unwind is done with irqs enabled however SLUB may call it with
irqs disabled while creating a new SLUB cache.

2
debian/patches/features/all/rt/ata-disable-interrupts-if-non-rt.patch vendored
View File

@ -1,7 +1,7 @@
From: Steven Rostedt <srostedt@redhat.com>
Date: Fri, 3 Jul 2009 08:44:29 -0500
Subject: ata: Do not disable interrupts in ide code for preempt-rt
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Use the local_irq_*_nort variants.

2
debian/patches/features/all/rt/blk-mq-revert-raw-locks-post-pone-notifier-to-POST_D.patchto-POST_D.patch vendored
View File

@ -2,7 +2,7 @@ From de8fa902784181346b91bd121fba824a588fa99c Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat, 3 May 2014 11:00:29 +0200
Subject: [PATCH] blk-mq: revert raw locks, post pone notifier to POST_DEAD
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The blk_mq_cpu_notify_lock should be raw because some CPU down levels
are called with interrupts off. The notifier itself calls currently one

2
debian/patches/features/all/rt/block-blk-mq-use-swait.patch vendored
View File

@ -2,7 +2,7 @@ From 707f90fbaa66cfe72a8543121474edce9319d9d6 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 13 Feb 2015 11:01:26 +0100
Subject: [PATCH] block: blk-mq: use swait
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
| BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:914
| in_atomic(): 1, irqs_disabled(): 0, pid: 255, name: kworker/u257:6

2
debian/patches/features/all/rt/block-mq-don-t-complete-requests-via-IPI.patch vendored
View File

@ -2,7 +2,7 @@ From 9945a1974d877a9accfd623dcfe78ffd9dd7bb86 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 29 Jan 2015 15:10:08 +0100
Subject: [PATCH] block/mq: don't complete requests via IPI
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The IPI runs in hardirq context and there are sleeping locks. This patch
moves the completion into a workqueue.

2
debian/patches/features/all/rt/block-mq-drop-per-ctx-cpu_lock.patch vendored
View File

@ -2,7 +2,7 @@ From 58fe6c3ba939278c159dfe7152889667b2685ea9 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 18 Feb 2015 18:37:26 +0100
Subject: [PATCH] block/mq: drop per ctx cpu_lock
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
While converting the get_cpu() to get_cpu_light() I added a cpu lock to
ensure the same code is not invoked twice on the same CPU. And now I run

2
debian/patches/features/all/rt/block-mq-drop-preempt-disable.patch vendored
View File

@ -1,6 +1,6 @@
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: block/mq: do not invoke preempt_disable()
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
preempt_disable() and get_cpu() don't play well together with the sleeping
locks it tries to allocate later.

2
debian/patches/features/all/rt/block-mq-use-cpu_light.patch vendored
View File

@ -2,7 +2,7 @@ From 7632d1dd96f75bdba997003fa61ab14e57afb0fe Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 9 Apr 2014 10:37:23 +0200
Subject: [PATCH 5/5] block: mq: use cpu_light()
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
there is a might sleep splat because get_cpu() disables preemption and
later we grab a lock. As a workaround for this we use get_cpu_light()

2
debian/patches/features/all/rt/block-shorten-interrupt-disabled-regions.patch vendored
View File

@ -1,7 +1,7 @@
Subject: block: Shorten interrupt disabled regions
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 22 Jun 2011 19:47:02 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Moving the blk_sched_flush_plug() call out of the interrupt/preempt
disabled region in the scheduler allows us to replace

2
debian/patches/features/all/rt/block-use-cpu-chill.patch vendored
View File

@ -1,7 +1,7 @@
Subject: block: Use cpu_chill() for retry loops
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 20 Dec 2012 18:28:26 +0100
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Retry loops on RT might loop forever when the modifying side was
preempted. Steven also observed a live lock when there was a

2
debian/patches/features/all/rt/bug-rt-dependend-variants.patch vendored
View File

@ -1,7 +1,7 @@
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:29:58 -0500
Subject: bug: BUG_ON/WARN_ON variants dependend on RT/!RT
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2
debian/patches/features/all/rt/cgroups-scheduling-while-atomic-in-cgroup-code.patch vendored
View File

@ -2,7 +2,7 @@ From eebd25188161f4e2079676e1db2f613375cfebf0 Mon Sep 17 00:00:00 2001
From: Mike Galbraith <umgwanakikbuti@gmail.com>
Date: Sat, 21 Jun 2014 10:09:48 +0200
Subject: [PATCH] scheduling while atomic in cgroup code
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
mm, memcg: make refill_stock() use get_cpu_light()

2
debian/patches/features/all/rt/cgroups-use-simple-wait-in-css_release.patch vendored
View File

@ -2,7 +2,7 @@ From 11a11a8da86fcba45725b4786bce03189d9ff2f9 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 13 Feb 2015 15:52:24 +0100
Subject: [PATCH 2/2] cgroups: use simple wait in css_release()
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
To avoid:
|BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:914

2
debian/patches/features/all/rt/clocksource-tclib-allow-higher-clockrates.patch vendored
View File

@ -1,7 +1,7 @@
From: Benedikt Spranger <b.spranger@linutronix.de>
Date: Mon, 8 Mar 2010 18:57:04 +0100
Subject: clocksource: TCLIB: Allow higher clock rates for clock events
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
As default the TCLIB uses the 32KiHz base clock rate for clock events.
Add a compile time selection to allow higher clock resulution.

6
debian/patches/features/all/rt/completion-use-simple-wait-queues.patch vendored
View File

@ -1,7 +1,7 @@
Subject: completion: Use simple wait queues
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 11 Jan 2013 11:23:51 +0100
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Completions have no long lasting callbacks and therefor do not need
the complex waitqueue variant. Use simple waitqueues which reduces the
@ -154,7 +154,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
EXPORT_SYMBOL(completion_done);
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2767,7 +2767,10 @@ void migrate_disable(void)
@@ -2813,7 +2813,10 @@ void migrate_disable(void)
}
#ifdef CONFIG_SCHED_DEBUG
@ -166,7 +166,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
#endif
if (p->migrate_disable) {
@@ -2798,7 +2801,10 @@ void migrate_enable(void)
@@ -2844,7 +2847,10 @@ void migrate_enable(void)
}
#ifdef CONFIG_SCHED_DEBUG

4
debian/patches/features/all/rt/cond-resched-lock-rt-tweak.patch vendored
View File

@ -1,7 +1,7 @@
Subject: cond-resched-lock-rt-tweak.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 17 Jul 2011 22:51:33 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
@ -10,7 +10,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2918,7 +2918,7 @@ extern int _cond_resched(void);
@@ -2964,7 +2964,7 @@ extern int _cond_resched(void);
extern int __cond_resched_lock(spinlock_t *lock);

8
debian/patches/features/all/rt/cond-resched-softirq-rt.patch vendored
View File

@ -1,7 +1,7 @@
Subject: cond-resched-softirq-fix.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 14 Jul 2011 09:56:44 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
@ -11,7 +11,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2929,12 +2929,16 @@ extern int __cond_resched_lock(spinlock_
@@ -2975,12 +2975,16 @@ extern int __cond_resched_lock(spinlock_
__cond_resched_lock(lock); \
})
@ -30,7 +30,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
{
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4320,6 +4320,7 @@ int __cond_resched_lock(spinlock_t *lock
@@ -4366,6 +4366,7 @@ int __cond_resched_lock(spinlock_t *lock
}
EXPORT_SYMBOL(__cond_resched_lock);
@ -38,7 +38,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
int __sched __cond_resched_softirq(void)
{
BUG_ON(!in_softirq());
@@ -4333,6 +4334,7 @@ int __sched __cond_resched_softirq(void)
@@ -4379,6 +4380,7 @@ int __sched __cond_resched_softirq(void)
return 0;
}
EXPORT_SYMBOL(__cond_resched_softirq);

2
debian/patches/features/all/rt/condition-migration_disable-on-lock-acquisition.patch vendored
View File

@ -2,7 +2,7 @@ From 56f43bce737d3f28ad470c95fa84f824cb0d55ad Mon Sep 17 00:00:00 2001
From: Nicholas Mc Guire <der.herr@hofr.at>
Date: Thu, 21 Nov 2013 22:52:30 -0500
Subject: [PATCH 2/2] condition migration_disable on lock acquisition
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
No need to unconditionally migrate_disable (what is it protecting ?) and
re-enable on failure to acquire the lock.

2
debian/patches/features/all/rt/cpu-hotplug-Document-why-PREEMPT_RT-uses-a-spinlock.patch vendored
View File

@ -2,7 +2,7 @@ From 107fb2b43f5c80686ee6454713f4963728ca2737 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <rostedt@goodmis.org>
Date: Thu, 5 Dec 2013 09:16:52 -0500
Subject: [PATCH] cpu hotplug: Document why PREEMPT_RT uses a spinlock
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The patch:

2
debian/patches/features/all/rt/cpu-rt-make-hotplug-lock-a-sleeping-spinlock-on-rt.patch vendored
View File

@ -1,7 +1,7 @@
Subject: cpu: Make hotplug.lock a "sleeping" spinlock on RT
From: Steven Rostedt <rostedt@goodmis.org>
Date: Fri, 02 Mar 2012 10:36:57 -0500
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Tasks can block on hotplug.lock in pin_current_cpu(), but their state
might be != RUNNING. So the mutex wakeup will set the state

12
debian/patches/features/all/rt/cpu-rt-rework-cpu-down.patch vendored
View File

@ -1,7 +1,7 @@
From: Steven Rostedt <srostedt@redhat.com>
Date: Mon, 16 Jul 2012 08:07:43 +0000
Subject: cpu/rt: Rework cpu down for PREEMPT_RT
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Bringing a CPU down is a pain with the PREEMPT_RT kernel because
tasks can be preempted in many more places than in non-RT. In
@ -57,7 +57,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2163,6 +2163,10 @@ extern void do_set_cpus_allowed(struct t
@@ -2209,6 +2209,10 @@ extern void do_set_cpus_allowed(struct t
extern int set_cpus_allowed_ptr(struct task_struct *p,
const struct cpumask *new_mask);
@ -68,7 +68,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
#else
static inline void do_set_cpus_allowed(struct task_struct *p,
const struct cpumask *new_mask)
@@ -2175,6 +2179,9 @@ static inline int set_cpus_allowed_ptr(s
@@ -2221,6 +2225,9 @@ static inline int set_cpus_allowed_ptr(s
return -EINVAL;
return 0;
}
@ -457,7 +457,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
*/
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2709,7 +2709,7 @@ void migrate_disable(void)
@@ -2755,7 +2755,7 @@ void migrate_disable(void)
{
struct task_struct *p = current;
@ -466,7 +466,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
#ifdef CONFIG_SCHED_DEBUG
p->migrate_disable_atomic++;
#endif
@@ -2739,7 +2739,7 @@ void migrate_enable(void)
@@ -2785,7 +2785,7 @@ void migrate_enable(void)
unsigned long flags;
struct rq *rq;
@ -475,7 +475,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
#ifdef CONFIG_SCHED_DEBUG
p->migrate_disable_atomic--;
#endif
@@ -4909,6 +4909,84 @@ void do_set_cpus_allowed(struct task_str
@@ -4955,6 +4955,84 @@ void do_set_cpus_allowed(struct task_str
cpumask_copy(&p->cpus_allowed, new_mask);
}

2
debian/patches/features/all/rt/cpu-rt-variants.patch vendored
View File

@ -1,7 +1,7 @@
Subject: cpu-rt-variants.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 17 Jun 2011 15:42:38 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/cpu_chill-Add-a-UNINTERRUPTIBLE-hrtimer_nanosleep.patch vendored
View File

@ -2,7 +2,7 @@ From a1b3b9eafb916f839a09dcde745518a5ad6703db Mon Sep 17 00:00:00 2001
From: Steven Rostedt <rostedt@goodmis.org>
Date: Tue, 4 Mar 2014 12:28:32 -0500
Subject: [PATCH] cpu_chill: Add a UNINTERRUPTIBLE hrtimer_nanosleep
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
We hit another bug that was caused by switching cpu_chill() from
msleep() to hrtimer_nanosleep().

2
debian/patches/features/all/rt/cpu_down_move_migrate_enable_back.patch vendored
View File

@ -2,7 +2,7 @@ From linux-rt-users-owner@vger.kernel.org Thu Nov 7 03:07:12 2013
From: Tiejun Chen <tiejun.chen@windriver.com>
Subject: [v1][PATCH] cpu_down: move migrate_enable() back
Date: Thu, 7 Nov 2013 10:06:07 +0800
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Commit 08c1ab68, "hotplug-use-migrate-disable.patch", intends to
use migrate_enable()/migrate_disable() to replace that combination

2
debian/patches/features/all/rt/cpufreq-drop-K8-s-driver-from-beeing-selected.patch vendored
View File

@ -2,7 +2,7 @@ From 748dfbec410da5366c04e9b85dbc11558aae1b73 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 9 Apr 2015 15:23:01 +0200
Subject: [PATCH] cpufreq: drop K8's driver from beeing selected
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Ralf posted a picture of a backtrace from

2
debian/patches/features/all/rt/cpumask-disable-offstack-on-rt.patch vendored
View File

@ -1,7 +1,7 @@
Subject: cpumask: Disable CONFIG_CPUMASK_OFFSTACK for RT
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 14 Dec 2011 01:03:49 +0100
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
We can't deal with the cpumask allocations which happen in atomic
context (see arch/x86/kernel/apic/io_apic.c) on RT right now.

2
debian/patches/features/all/rt/crypto-Reduce-preempt-disabled-regions-more-algos.patch vendored
View File

@ -2,7 +2,7 @@ From 0fcf777e2f217e61564bd30a2c39cb49d0e0b8c3 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 21 Feb 2014 17:24:04 +0100
Subject: [PATCH] crypto: Reduce preempt disabled regions, more algos
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Don Estabrook reported
| kernel: WARNING: CPU: 2 PID: 858 at kernel/sched/core.c:2428 migrate_disable+0xed/0x100()

2
debian/patches/features/all/rt/debugobjects-rt.patch vendored
View File

@ -1,7 +1,7 @@
Subject: debugobjects-rt.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 17 Jul 2011 21:41:35 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/dm-make-rt-aware.patch vendored
View File

@ -1,7 +1,7 @@
Subject: dm: Make rt aware
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 14 Nov 2011 23:06:09 +0100
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Use the BUG_ON_NORT variant for the irq_disabled() checks. RT has
interrupts legitimately enabled here as we cant deadlock against the

2
debian/patches/features/all/rt/drivers-net-8139-disable-irq-nosync.patch vendored
View File

@ -1,7 +1,7 @@
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:29:24 -0500
Subject: drivers/net: Use disable_irq_nosync() in 8139too
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Use disable_irq_nosync() instead of disable_irq() as this might be
called in atomic context with netpoll.

2
debian/patches/features/all/rt/drivers-net-fix-livelock-issues.patch vendored
View File

@ -1,7 +1,7 @@
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sat, 20 Jun 2009 11:36:54 +0200
Subject: drivers/net: fix livelock issues
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Preempt-RT runs into a live lock issue with the NETDEV_TX_LOCKED micro
optimization. The reason is that the softirq thread is rescheduling

2
debian/patches/features/all/rt/drivers-net-vortex-fix-locking-issues.patch vendored
View File

@ -1,7 +1,7 @@
From: Steven Rostedt <rostedt@goodmis.org>
Date: Fri, 3 Jul 2009 08:30:00 -0500
Subject: drivers/net: vortex fix locking issues
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Argh, cut and paste wasn't enough...

2
debian/patches/features/all/rt/drivers-random-reduce-preempt-disabled-region.patch vendored
View File

@ -1,7 +1,7 @@
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:29:30 -0500
Subject: drivers: random: Reduce preempt disabled region
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
No need to keep preemption disabled across the whole function.

2
debian/patches/features/all/rt/drivers-tty-fix-omap-lock-crap.patch vendored
View File

@ -1,7 +1,7 @@
Subject: drivers-tty-fix-omap-lock-crap.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 28 Jul 2011 13:32:57 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/drivers-tty-pl011-irq-disable-madness.patch vendored
View File

@ -1,7 +1,7 @@
Subject: drivers-tty-pl011-irq-disable-madness.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 08 Jan 2013 21:36:51 +0100
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/drm-i915-drop-trace_i915_gem_ring_dispatch-onrt.patch vendored
View File

@ -2,7 +2,7 @@ From d841118ac80c5bfb18f47984bc40687eed08b714 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 25 Apr 2013 18:12:52 +0200
Subject: [PATCH] drm/i915: drop trace_i915_gem_ring_dispatch on rt
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
This tracepoint is responsible for:

2
debian/patches/features/all/rt/early-printk-consolidate.patch vendored
View File

@ -1,7 +1,7 @@
Subject: early-printk-consolidate.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sat, 23 Jul 2011 11:04:08 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/epoll-use-get-cpu-light.patch vendored
View File

@ -1,7 +1,7 @@
Subject: epoll.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 08 Jul 2011 16:35:35 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/fix-rt-int3-x86_32-3.2-rt.patch vendored
View File

@ -1,6 +1,6 @@
From: Steven Rostedt <rostedt@goodmis.org>
Subject: x86: Do not disable preemption in int3 on 32bit
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Preemption must be disabled before enabling interrupts in do_trap
on x86_64 because the stack in use for int3 and debug is a per CPU

2
debian/patches/features/all/rt/fixup_opencoded_completions.patch vendored
View File

@ -2,7 +2,7 @@ From 53a9508f5983092928b0e6e12f400b686e1f04b1 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 28 Oct 2013 11:50:06 +0100
Subject: [PATCH] a few open coded completions
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---

2
debian/patches/features/all/rt/fs-aio-simple-simple-work.patch vendored
View File

@ -2,7 +2,7 @@ From dff0dd4ff87b8f41b438f8b9bb32d2343943bb32 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 16 Feb 2015 18:49:10 +0100
Subject: [PATCH] fs/aio: simple simple work
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
|BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:768
|in_atomic(): 1, irqs_disabled(): 0, pid: 26, name: rcuos/2

2
debian/patches/features/all/rt/fs-block-rt-support.patch vendored
View File

@ -1,7 +1,7 @@
Subject: fs-block-rt-support.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 14 Jun 2011 17:05:09 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

2
debian/patches/features/all/rt/fs-dcache-use-cpu-chill-in-trylock-loops.patch vendored
View File

@ -1,7 +1,7 @@
Subject: fs: dcache: Use cpu_chill() in trylock loops
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 07 Mar 2012 21:00:34 +0100
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Retry loops on RT might loop forever when the modifying side was
preempted. Use cpu_chill() instead of cpu_relax() to let the system

2
debian/patches/features/all/rt/fs-jbd-pull-plug-when-waiting-for-space.patch vendored
View File

@ -1,7 +1,7 @@
From: Mike Galbraith <mgalbraith@suse.de>
Date: Wed, 11 Jul 2012 22:05:20 +0000
Subject: fs, jbd: pull your plug when waiting for space
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
With an -rt kernel, and a heavy sync IO load, tasks can jam
up on journal locks without unplugging, which can lead to

2
debian/patches/features/all/rt/fs-jbd-replace-bh_state-lock.patch vendored
View File

@ -1,7 +1,7 @@
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 18 Mar 2011 10:11:25 +0100
Subject: fs: jbd/jbd2: Make state lock and journal head lock rt safe
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
bit_spin_locks break under RT.

2
debian/patches/features/all/rt/fs-jbd2-pull-your-plug-when-waiting-for-space.patch vendored
View File

@ -2,7 +2,7 @@ From c28e07715162bb1e1567a935b45772ca85a5267c Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 17 Feb 2014 17:30:03 +0100
Subject: [PATCH] fs: jbd2: pull your plug when waiting for space
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Two cps in parallel managed to stall the the ext4 fs. It seems that
journal code is either waiting for locks or sleeping waiting for

2
debian/patches/features/all/rt/fs-namespace-preemption-fix.patch vendored
View File

@ -1,7 +1,7 @@
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 19 Jul 2009 08:44:27 -0500
Subject: fs: namespace preemption fix
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
On RT we cannot loop with preemption disabled here as
mnt_make_readonly() might have been preempted. We can safely enable

2
debian/patches/features/all/rt/fs-ntfs-disable-interrupt-non-rt.patch vendored
View File

@ -1,7 +1,7 @@
From: Mike Galbraith <efault@gmx.de>
Date: Fri, 3 Jul 2009 08:44:12 -0500
Subject: fs: ntfs: disable interrupt only on !RT
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
On Sat, 2007-10-27 at 11:44 +0200, Ingo Molnar wrote:
> * Nick Piggin <nickpiggin@yahoo.com.au> wrote:

2
debian/patches/features/all/rt/fs-replace-bh_uptodate_lock-for-rt.patch vendored
View File

@ -1,7 +1,7 @@
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 18 Mar 2011 09:18:52 +0100
Subject: buffer_head: Replace bh_uptodate_lock for -rt
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Wrap the bit_spin_lock calls into a separate inline and add the RT
replacements with a real spinlock.

2
debian/patches/features/all/rt/ftrace-migrate-disable-tracing.patch vendored
View File

@ -1,7 +1,7 @@
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 17 Jul 2011 21:56:42 +0200
Subject: ftrace-migrate-disable-tracing.patch
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

225
debian/patches/features/all/rt/futex-avoid-double-wake-up-in-PI-futex-wait-wake-on-.patch vendored Normal file
View File

@ -0,0 +1,225 @@
From 460bffd867ab18d151650bf9cb83207e56cc0947 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 18 Feb 2015 20:17:31 +0100
Subject: [PATCH] futex: avoid double wake up in PI futex wait / wake on -RT
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
The boosted priority is reverted after the unlock but before the
futex_hash_bucket (hb) has been accessed. The result is that we boost the
task, deboost the task, boost again for the hb lock, deboost again.
A sched trace of this scenario looks the following:
| med_prio-93 sched_wakeup: comm=high_prio pid=92 prio=9 success=1 target_cpu=000
| med_prio-93 sched_switch: prev_comm=med_prio prev_pid=93 prev_prio=29 prev_state=R ==> next_comm=high_prio next_pid=92 next_prio=9
|high_prio-92 sched_pi_setprio: comm=low_prio pid=91 oldprio=120 newprio=9
|high_prio-92 sched_switch: prev_comm=high_prio prev_pid=92 prev_prio=9 prev_state=S ==> next_comm=low_prio next_pid=91 next_prio=9
| low_prio-91 sched_wakeup: comm=high_prio pid=92 prio=9 success=1 target_cpu=000
| low_prio-91 sched_pi_setprio: comm=low_prio pid=91 oldprio=9 newprio=120
| low_prio-91 sched_switch: prev_comm=low_prio prev_pid=91 prev_prio=120 prev_state=R+ ==> next_comm=high_prio next_pid=92 next_prio=9
|high_prio-92 sched_pi_setprio: comm=low_prio pid=91 oldprio=120 newprio=9
|high_prio-92 sched_switch: prev_comm=high_prio prev_pid=92 prev_prio=9 prev_state=D ==> next_comm=low_prio next_pid=91 next_prio=9
| low_prio-91 sched_wakeup: comm=high_prio pid=92 prio=9 success=1 target_cpu=000
| low_prio-91 sched_pi_setprio: comm=low_prio pid=91 oldprio=9 newprio=120
| low_prio-91 sched_switch: prev_comm=low_prio prev_pid=91 prev_prio=120 prev_state=R+ ==> next_comm=high_prio next_pid=92 next_prio=9
We see four sched_pi_setprio() invocation but ideally two would be enough.
The patch tries to avoid the double wakeup by a wake up once the hb lock is
released. The same test case:
| med_prio-21 sched_wakeup: comm=high_prio pid=20 prio=9 success=1 target_cpu=000
| med_prio-21 sched_switch: prev_comm=med_prio prev_pid=21 prev_prio=29 prev_state=R ==> next_comm=high_prio next_pid=20 next_prio=9
|high_prio-20 sched_pi_setprio: comm=low_prio pid=19 oldprio=120 newprio=9
|high_prio-20 sched_switch: prev_comm=high_prio prev_pid=20 prev_prio=9 prev_state=S ==> next_comm=low_prio next_pid=19 next_prio=9
| low_prio-19 sched_wakeup: comm=high_prio pid=20 prio=9 success=1 target_cpu=000
| low_prio-19 sched_pi_setprio: comm=low_prio pid=19 oldprio=9 newprio=120
| low_prio-19 sched_switch: prev_comm=low_prio prev_pid=19 prev_prio=120 prev_state=R+ ==> next_comm=high_prio next_pid=20 next_prio=9
only two sched_pi_setprio() invocations as one would expect and see
without -RT.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/futex.c | 32 +++++++++++++++++++++++++++++---
kernel/locking/rtmutex.c | 40 +++++++++++++++++++++++++++++-----------
kernel/locking/rtmutex_common.h | 4 ++++
3 files changed, 62 insertions(+), 14 deletions(-)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1117,11 +1117,13 @@ static void mark_wake_futex(struct wake_
q->lock_ptr = NULL;
}
-static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
+static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this,
+ struct futex_hash_bucket *hb)
{
struct task_struct *new_owner;
struct futex_pi_state *pi_state = this->pi_state;
u32 uninitialized_var(curval), newval;
+ bool deboost;
int ret = 0;
if (!pi_state)
@@ -1173,7 +1175,17 @@ static int wake_futex_pi(u32 __user *uad
raw_spin_unlock_irq(&new_owner->pi_lock);
raw_spin_unlock(&pi_state->pi_mutex.wait_lock);
- rt_mutex_unlock(&pi_state->pi_mutex);
+
+ deboost = rt_mutex_futex_unlock(&pi_state->pi_mutex);
+
+ /*
+ * We deboost after dropping hb->lock. That prevents a double
+ * wakeup on RT.
+ */
+ spin_unlock(&hb->lock);
+
+ if (deboost)
+ rt_mutex_adjust_prio(current);
return 0;
}
@@ -2413,13 +2425,26 @@ static int futex_unlock_pi(u32 __user *u
*/
match = futex_top_waiter(hb, &key);
if (match) {
- ret = wake_futex_pi(uaddr, uval, match);
+ ret = wake_futex_pi(uaddr, uval, match, hb);
+
+ /*
+ * In case of success wake_futex_pi dropped the hash
+ * bucket lock.
+ */
+ if (!ret)
+ goto out_putkey;
+
/*
* The atomic access to the futex value generated a
* pagefault, so retry the user-access and the wakeup:
*/
if (ret == -EFAULT)
goto pi_faulted;
+
+ /*
+ * wake_futex_pi has detected invalid state. Tell user
+ * space.
+ */
goto out_unlock;
}
@@ -2440,6 +2465,7 @@ static int futex_unlock_pi(u32 __user *u
out_unlock:
spin_unlock(&hb->lock);
+out_putkey:
put_futex_key(&key);
return ret;
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -300,7 +300,7 @@ static void __rt_mutex_adjust_prio(struc
* of task. We do not use the spin_xx_mutex() variants here as we are
* outside of the debug path.)
*/
-static void rt_mutex_adjust_prio(struct task_struct *task)
+void rt_mutex_adjust_prio(struct task_struct *task)
{
unsigned long flags;
@@ -957,8 +957,9 @@ static int task_blocks_on_rt_mutex(struc
/*
* Wake up the next waiter on the lock.
*
- * Remove the top waiter from the current tasks pi waiter list and
- * wake it up.
+ * Remove the top waiter from the current tasks pi waiter list,
+ * wake it up and return whether the current task needs to undo
+ * a potential priority boosting.
*
* Called with lock->wait_lock held.
*/
@@ -1255,7 +1256,7 @@ static inline int rt_mutex_slowtrylock(s
/*
* Slow path to release a rt-mutex:
*/
-static void __sched
+static bool __sched
rt_mutex_slowunlock(struct rt_mutex *lock)
{
raw_spin_lock(&lock->wait_lock);
@@ -1298,7 +1299,7 @@ rt_mutex_slowunlock(struct rt_mutex *loc
while (!rt_mutex_has_waiters(lock)) {
/* Drops lock->wait_lock ! */
if (unlock_rt_mutex_safe(lock) == true)
- return;
+ return false;
/* Relock the rtmutex and try again */
raw_spin_lock(&lock->wait_lock);
}
@@ -1311,8 +1312,7 @@ rt_mutex_slowunlock(struct rt_mutex *loc
raw_spin_unlock(&lock->wait_lock);
- /* Undo pi boosting if necessary: */
- rt_mutex_adjust_prio(current);
+ return true;
}
/*
@@ -1363,12 +1363,14 @@ rt_mutex_fasttrylock(struct rt_mutex *lo
static inline void
rt_mutex_fastunlock(struct rt_mutex *lock,
- void (*slowfn)(struct rt_mutex *lock))
+ bool (*slowfn)(struct rt_mutex *lock))
{
- if (likely(rt_mutex_cmpxchg(lock, current, NULL)))
+ if (likely(rt_mutex_cmpxchg(lock, current, NULL))) {
rt_mutex_deadlock_account_unlock(current);
- else
- slowfn(lock);
+ } else if (slowfn(lock)) {
+ /* Undo pi boosting if necessary: */
+ rt_mutex_adjust_prio(current);
+ }
}
/**
@@ -1463,6 +1465,22 @@ void __sched rt_mutex_unlock(struct rt_m
EXPORT_SYMBOL_GPL(rt_mutex_unlock);
/**
+ * rt_mutex_futex_unlock - Futex variant of rt_mutex_unlock
+ * @lock: the rt_mutex to be unlocked
+ *
+ * Returns: true/false indicating whether priority adjustment is
+ * required or not.
+ */
+bool __sched rt_mutex_futex_unlock(struct rt_mutex *lock)
+{
+ if (likely(rt_mutex_cmpxchg(lock, current, NULL))) {
+ rt_mutex_deadlock_account_unlock(current);
+ return false;
+ }
+ return rt_mutex_slowunlock(lock);
+}
+
+/**
* rt_mutex_destroy - mark a mutex unusable
* @lock: the mutex to be destroyed
*
--- a/kernel/locking/rtmutex_common.h
+++ b/kernel/locking/rtmutex_common.h
@@ -132,6 +132,10 @@ extern int rt_mutex_finish_proxy_lock(st
struct rt_mutex_waiter *waiter);
extern int rt_mutex_timed_futex_lock(struct rt_mutex *l, struct hrtimer_sleeper *to);
+extern bool rt_mutex_futex_unlock(struct rt_mutex *lock);
+
+extern void rt_mutex_adjust_prio(struct task_struct *task);
+
#ifdef CONFIG_DEBUG_RT_MUTEXES
# include "rtmutex-debug.h"
#else

4
debian/patches/features/all/rt/futex-requeue-pi-fix.patch vendored
View File

@ -1,6 +1,6 @@
From: Steven Rostedt <rostedt@goodmis.org>
Subject: futex: Fix bug on when a requeued RT task times out
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Requeue with timeout causes a bug with PREEMPT_RT_FULL.
@ -65,7 +65,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
}
/*
@@ -1584,6 +1585,35 @@ int rt_mutex_start_proxy_lock(struct rt_
@@ -1602,6 +1603,35 @@ int rt_mutex_start_proxy_lock(struct rt_
return 1;
}

2
debian/patches/features/all/rt/genirq-disable-irqpoll-on-rt.patch vendored
View File

@ -1,7 +1,7 @@
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:29:57 -0500
Subject: genirq: disable irqpoll on -rt
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Creates long latencies for no value

2
debian/patches/features/all/rt/genirq-do-not-invoke-the-affinity-callback-via-a-wor.patch vendored
View File

@ -2,7 +2,7 @@ From 76666dbbdd40e963e7df84c123fc9aea4a2bcc69 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 21 Aug 2013 17:48:46 +0200
Subject: [PATCH] genirq: do not invoke the affinity callback via a workqueue
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Joe Korty reported, that __irq_set_affinity_locked() schedules a
workqueue while holding a rawlock which results in a might_sleep()

2
debian/patches/features/all/rt/genirq-force-threading.patch vendored
View File

@ -1,7 +1,7 @@
Subject: genirq-force-threading.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 03 Apr 2011 11:57:29 +0200
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.5-rt3.tar.xz
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

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