From 75437bb304b20a2b350b9a8e9f9238d5e24e12ba Mon Sep 17 00:00:00 2001 From: Pan Xinhui Date: Tue, 10 Jan 2017 02:56:46 -0500 Subject: locking/pvqspinlock: Don't wait if vCPU is preempted If prev node is not in running state or its vCPU is preempted, we can give up our vCPU slices in pv_wait_node() ASAP. Signed-off-by: Pan Xinhui Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: longman@redhat.com Link: http://lkml.kernel.org/r/1484035006-6787-1-git-send-email-xinhui.pan@linux.vnet.ibm.com [ Fixed typos in the changelog, removed ugly linebreak from the code. ] Signed-off-by: Ingo Molnar --- kernel/locking/qspinlock_paravirt.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/locking/qspinlock_paravirt.h') diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index e3b5520005db..e6b2f7ad3e51 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -263,7 +263,7 @@ 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); } /* -- cgit v1.2.3