From: Zqiang <qiang1.zhang@intel.com>
To: peterz@infradead.org, mingo@redhat.com, will@kernel.org,
longman@redhat.com
Cc: linux-kernel@vger.kernel.org, qiang1.zhang@intel.com
Subject: [PATCH v2] locking/rtmutex: Fix incorrect spinning condition
Date: Fri, 17 Dec 2021 15:42:07 +0800 [thread overview]
Message-ID: <20211217074207.77425-1-qiang1.zhang@intel.com> (raw)
When the lock owner is on CPU and not need resched, the current waiter
need to be checked, if it not longer top the waiter, stop spinning.
Fixes: c3123c431447 ("locking/rtmutex: Dont dereference waiter lockless")
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
---
v1->v2:
Modify description information.
kernel/locking/rtmutex.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 0c1f2e3f019a..8555c4efe97c 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1383,7 +1383,7 @@ static bool rtmutex_spin_on_owner(struct rt_mutex_base *lock,
* - the VCPU on which owner runs is preempted
*/
if (!owner_on_cpu(owner) || need_resched() ||
- rt_mutex_waiter_is_top_waiter(lock, waiter)) {
+ !rt_mutex_waiter_is_top_waiter(lock, waiter)) {
res = false;
break;
}
--
2.25.1
next reply other threads:[~2021-12-17 7:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-17 7:42 Zqiang [this message]
2021-12-17 20:53 ` Thomas Gleixner
2021-12-18 7:24 ` Zhang, Qiang1
2021-12-18 9:34 ` Thomas Gleixner
2021-12-20 1:45 ` Zhang, Qiang1
2021-12-18 10:01 ` [tip: locking/core] locking/rtmutex: Fix incorrect condition in rtmutex_spin_on_owner() tip-bot2 for Zqiang
2021-12-19 21:09 ` [PATCH v2] locking/rtmutex: Fix incorrect spinning condition Waiman Long
2021-12-20 1:54 ` Zhang, Qiang1
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