74 lines
2.7 KiB
Diff
74 lines
2.7 KiB
Diff
From f9031ff7ec4df88f9c03e01ec116914c446bc7ed Mon Sep 17 00:00:00 2001
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Message-Id: <f9031ff7ec4df88f9c03e01ec116914c446bc7ed.1601675153.git.zanussi@kernel.org>
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In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Wed, 26 Jun 2019 17:44:27 +0200
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Subject: [PATCH 275/333] Revert "futex: workaround migrate_disable/enable in
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different context"
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz
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[ Upstream commit a71221d81cc4873891ae44f3aa02df596079b786 ]
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Drop the RT fixup, the futex code will be changed to avoid the need for
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the workaround.
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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---
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kernel/futex.c | 19 -------------------
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1 file changed, 19 deletions(-)
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diff --git a/kernel/futex.c b/kernel/futex.c
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index 1f9dd186b00c..9900c3f30124 100644
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--- a/kernel/futex.c
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+++ b/kernel/futex.c
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@@ -2895,14 +2895,6 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags,
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* before __rt_mutex_start_proxy_lock() is done.
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*/
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raw_spin_lock_irq(&q.pi_state->pi_mutex.wait_lock);
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- /*
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- * the migrate_disable() here disables migration in the in_atomic() fast
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- * path which is enabled again in the following spin_unlock(). We have
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- * one migrate_disable() pending in the slow-path which is reversed
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- * after the raw_spin_unlock_irq() where we leave the atomic context.
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- */
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- migrate_disable();
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-
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spin_unlock(q.lock_ptr);
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/*
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* __rt_mutex_start_proxy_lock() unconditionally enqueues the @rt_waiter
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@@ -2911,7 +2903,6 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags,
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*/
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ret = __rt_mutex_start_proxy_lock(&q.pi_state->pi_mutex, &rt_waiter, current);
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raw_spin_unlock_irq(&q.pi_state->pi_mutex.wait_lock);
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- migrate_enable();
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if (ret) {
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if (ret == 1)
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@@ -3060,21 +3051,11 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
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* rt_waiter. Also see the WARN in wake_futex_pi().
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*/
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raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
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- /*
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- * Magic trickery for now to make the RT migrate disable
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- * logic happy. The following spin_unlock() happens with
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- * interrupts disabled so the internal migrate_enable()
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- * won't undo the migrate_disable() which was issued when
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- * locking hb->lock.
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- */
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- migrate_disable();
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spin_unlock(&hb->lock);
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/* drops pi_state->pi_mutex.wait_lock */
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ret = wake_futex_pi(uaddr, uval, pi_state);
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- migrate_enable();
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-
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put_pi_state(pi_state);
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/*
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--
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2.17.1
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