summaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorKonstantin Khlebnikov <khlebnikov@yandex-team.ru>2015-07-15 12:52:04 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-10-27 09:51:58 +0900
commit98197d3de58a62785be3e421864d6145955f197d (patch)
tree7c32b124ba6ddd924eccf5601d4aa9e4c23202a7 /kernel
parent3905f7abd0410acdd497661e84c7f6ef672c1e04 (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> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched/core.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8476206a1e19..4d870eb6086b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4232,7 +4232,7 @@ SYSCALL_DEFINE0(sched_yield)
int __sched _cond_resched(void)
{
- if (should_resched()) {
+ if (should_resched(0)) {
preempt_schedule_common();
return 1;
}
@@ -4250,7 +4250,7 @@ EXPORT_SYMBOL(_cond_resched);
*/
int __cond_resched_lock(spinlock_t *lock)
{
- int resched = should_resched();
+ int resched = should_resched(PREEMPT_LOCK_OFFSET);
int ret = 0;
lockdep_assert_held(lock);
@@ -4272,7 +4272,7 @@ int __sched __cond_resched_softirq(void)
{
BUG_ON(!in_softirq());
- if (should_resched()) {
+ if (should_resched(SOFTIRQ_DISABLE_OFFSET)) {
local_bh_enable();
preempt_schedule_common();
local_bh_disable();