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author | George Dunlap <george.dunlap@eu.citrix.com> | 2012-07-09 10:24:44 +0100 |
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committer | George Dunlap <george.dunlap@eu.citrix.com> | 2012-07-09 10:24:44 +0100 |
commit | 4e8f99fc6e93baff90fcff4993cc40f4be77b2df (patch) | |
tree | 991da118ed42d6e7ae96010e7d52a27c7aae7585 | |
parent | c279f333a7716b1b4e9f21beedaada751be1f2d5 (diff) | |
download | xen-4e8f99fc6e93baff90fcff4993cc40f4be77b2df.tar.gz xen-4e8f99fc6e93baff90fcff4993cc40f4be77b2df.tar.bz2 xen-4e8f99fc6e93baff90fcff4993cc40f4be77b2df.zip |
xen: Fix schedule()'s grabbing of the schedule lock
Because the location of the lock can change between the time you read
it and the time you grab it, the per-cpu schedule locks need to check
after lock acquisition that the lock location hasn't changed, and
release and re-try if so. This change was effected throughout the
source code, but one very important place was apparently missed: in
schedule() itself.
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Committed-by: Keir Fraser <keir@xen.org>
xen-unstable changeset: 25162:478bec603d3d
xen-unstable date: Tue Apr 10 10:41:30 2012 +0100
-rw-r--r-- | xen/common/schedule.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/xen/common/schedule.c b/xen/common/schedule.c index 1ed1bbb4ad..e06e44e690 100644 --- a/xen/common/schedule.c +++ b/xen/common/schedule.c @@ -1122,6 +1122,7 @@ static void schedule(void) bool_t tasklet_work_scheduled = 0; struct schedule_data *sd; struct task_slice next_slice; + int cpu = smp_processor_id(); ASSERT(!in_atomic()); @@ -1146,7 +1147,7 @@ static void schedule(void) BUG(); } - spin_lock_irq(sd->schedule_lock); + pcpu_schedule_lock_irq(cpu); stop_timer(&sd->s_timer); @@ -1163,7 +1164,7 @@ static void schedule(void) if ( unlikely(prev == next) ) { - spin_unlock_irq(sd->schedule_lock); + pcpu_schedule_unlock_irq(cpu); trace_continue_running(next); return continue_running(prev); } @@ -1201,7 +1202,7 @@ static void schedule(void) ASSERT(!next->is_running); next->is_running = 1; - spin_unlock_irq(sd->schedule_lock); + pcpu_schedule_unlock_irq(cpu); perfc_incr(sched_ctx); |