leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

KVM: Drop useless atomic test from timer function

Browse Source 
The current code tries to optimize the setting of
KVM_REQ_PENDING_TIMER but used atomic_inc_and_test - which always
returns true unless pending had the invalid value of -1 on entry. This
patch drops the test part preserving the original semantic but
expressing it less confusingly.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Jan Kiszka 2009-06-09 15:37:03 +02:00 committed by Avi Kivity
parent f7104db26a
commit 681405bfc7
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/x86/kvm/timer.c
View File

@ -15,9 +15,9 @@ static int __kvm_timer_fn(struct kvm_vcpu *vcpu, struct kvm_timer *ktimer)
* case anyway. * case anyway.
*/ */
if (ktimer->reinject || !atomic_read(&ktimer->pending)) { if (ktimer->reinject || !atomic_read(&ktimer->pending)) {
atomic_inc(&ktimer->pending);
/* FIXME: this code should not know anything about vcpus */ /* FIXME: this code should not know anything about vcpus */
if (!atomic_inc_and_test(&ktimer->pending)) set_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
set_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
} }
if (waitqueue_active(q)) if (waitqueue_active(q))