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Groups > linux.kernel > #1537113
| From | Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH] locking/pvqspinlock: Wait early if vcpu is preempted |
| Date | 2016-12-06 18:00 +0100 |
| Message-ID | <sLrfY-4AN-53@gated-at.bofh.it> (permalink) |
| Organization | linux.* mail to news gateway |
If prev node is not in runnig state or its cpu is preempted, we need wait early in pv_wait_node. After commit "sched/core: Introduce the vcpu_is_preempted(cpu) interface" kernel has knowledge of one vcpu is running or not. So lets use it. Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> --- kernel/locking/qspinlock_paravirt.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index e3b5520..48648dc 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -263,7 +263,8 @@ pv_wait_early(struct pv_node *prev, int loop) if ((loop & PV_PREV_CHECK_MASK) != 0) return false; - return READ_ONCE(prev->state) != vcpu_running; + return READ_ONCE(prev->state) != vcpu_running || + vcpu_is_preempted(prev->cpu); } /* -- 2.4.11
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[PATCH] locking/pvqspinlock: Wait early if vcpu is preempted Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-12-06 18:00 +0100
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