Commit-ID: 75437bb304b20a2b350b9a8e9f9238d5e24e12ba Gitweb: http://git.kernel.org/tip/75437bb304b20a2b350b9a8e9f9238d5e24e12ba Author: Pan Xinhui <xinhui....@linux.vnet.ibm.com> AuthorDate: Tue, 10 Jan 2017 02:56:46 -0500 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 12 Jan 2017 09:35:57 +0100
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 <xinhui....@linux.vnet.ibm.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: long...@redhat.com Link: http://lkml.kernel.org/r/1484035006-6787-1-git-send-email-xinhui....@linux.vnet.ibm.com [ Fixed typos in the changelog, removed ugly linebreak from the code. ] Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/locking/qspinlock_paravirt.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index e3b5520..e6b2f7a 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); } /*
