diff options
| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2015-07-15 12:52:04 +0300 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2015-11-16 11:27:24 +0000 |
| commit | b72279e4ca0b488f9724f830f0fe81c1a0c26cd8 (patch) | |
| tree | 1122241c60bbf74a398d1cb3188897cb2c7842e4 /include/asm-generic | |
| parent | 1f585b92809e14e13c4e31d2cd2117bbd9dd8074 (diff) | |
sched/preempt: Fix cond_resched_lock() and cond_resched_softirq()
commit fe32d3cd5e8eb0f82e459763374aa80797023403 upstream.
These functions check should_resched() before unlocking spinlock/bh-enable:
preempt_count always non-zero => should_resched() always returns false.
cond_resched_lock() worked iff spin_needbreak is set.
This patch adds argument "preempt_offset" to should_resched().
preempt_count offset constants for that:
PREEMPT_DISABLE_OFFSET - offset after preempt_disable()
PREEMPT_LOCK_OFFSET - offset after spin_lock()
SOFTIRQ_DISABLE_OFFSET - offset after local_bh_distable()
SOFTIRQ_LOCK_OFFSET - offset after spin_lock_bh()
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Graf <agraf@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: bdb438065890 ("sched: Extract the basic add/sub preempt_count modifiers")
Link: http://lkml.kernel.org/r/20150715095204.12246.98268.stgit@buzz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[ luis: backported to 3.16:
- some of the changes done in preempt_mask.h instead of preempt.h
- adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/preempt.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h index 1cd3f5d767a8..54352f4dde1a 100644 --- a/include/asm-generic/preempt.h +++ b/include/asm-generic/preempt.h @@ -74,9 +74,10 @@ static __always_inline bool __preempt_count_dec_and_test(void) /* * Returns true when we need to resched and can (barring IRQ state). */ -static __always_inline bool should_resched(void) +static __always_inline bool should_resched(int preempt_offset) { - return unlikely(!preempt_count() && tif_need_resched()); + return unlikely(preempt_count() == preempt_offset && + tif_need_resched()); } #ifdef CONFIG_PREEMPT |