52 lines
1.9 KiB
Diff
52 lines
1.9 KiB
Diff
From c088ed4daeabc07f8c6965869c812d90f6105e15 Mon Sep 17 00:00:00 2001
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Message-Id: <c088ed4daeabc07f8c6965869c812d90f6105e15.1601675152.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: Tue, 19 Feb 2019 16:59:15 +0100
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Subject: [PATCH 183/333] hrtimer: Don't lose state in cpu_chill()
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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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In cpu_chill() the state is set to TASK_UNINTERRUPTIBLE and a timer is
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programmed. On return the state is always TASK_RUNNING which means we
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lose the state if it was something other than RUNNING. Also
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set_current_state() sets ->task_state_change to within cpu_chill() which
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is not expected.
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Save the task state on entry and restore it on return. Simply set the
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state in order to avoid updating ->task_state_change.
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Cc: stable-rt@vger.kernel.org
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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kernel/time/hrtimer.c | 5 ++++-
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1 file changed, 4 insertions(+), 1 deletion(-)
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diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
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index 98a771065818..21a454557c8a 100644
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--- a/kernel/time/hrtimer.c
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+++ b/kernel/time/hrtimer.c
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@@ -1905,15 +1905,18 @@ void cpu_chill(void)
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{
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ktime_t chill_time;
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unsigned int freeze_flag = current->flags & PF_NOFREEZE;
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+ long saved_state;
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+ saved_state = current->state;
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chill_time = ktime_set(0, NSEC_PER_MSEC);
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- set_current_state(TASK_UNINTERRUPTIBLE);
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+ __set_current_state_no_track(TASK_UNINTERRUPTIBLE);
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current->flags |= PF_NOFREEZE;
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sleeping_lock_inc();
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schedule_hrtimeout(&chill_time, HRTIMER_MODE_REL_HARD);
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sleeping_lock_dec();
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if (!freeze_flag)
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current->flags &= ~PF_NOFREEZE;
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+ __set_current_state_no_track(saved_state);
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}
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EXPORT_SYMBOL(cpu_chill);
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#endif
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--
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2.17.1
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