LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
* [PATCH] KVM: X86: Limit timer frequency with more smaller interval
@ 2018-04-30  2:38 Wanpeng Li
  2018-04-30 12:31 ` Darren Kenny
  2018-05-04 12:28 ` Wanpeng Li
  0 siblings, 2 replies; 3+ messages in thread
From: Wanpeng Li @ 2018-04-30  2:38 UTC (permalink / raw)
  To: linux-kernel, kvm
  Cc: Paolo Bonzini, Radim Krčmář, Anthoine Bourgeois

From: Wanpeng Li <wanpengli@tencent.com>

Anthoine reported:
 The period used by Windows change over time but it can be 1 milliseconds
 or less. I saw the limit_periodic_timer_frequency print so 500
 microseconds is sometimes reached.

This patchs limits timer frequency with more smaller interval 200ms(5000Hz) 
to leave some headroom as Paolo suggested since Windows 10 changed the 
scheduler tick limit from 1024 Hz to 2048 Hz.

Reported-by: Anthoine Bourgeois <anthoine.bourgeois@blade-group.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com> 
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Anthoine Bourgeois <anthoine.bourgeois@blade-group.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
 arch/x86/kvm/x86.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 51ecd38..dc47073 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -114,7 +114,7 @@ module_param(ignore_msrs, bool, S_IRUGO | S_IWUSR);
 static bool __read_mostly report_ignored_msrs = true;
 module_param(report_ignored_msrs, bool, S_IRUGO | S_IWUSR);
 
-unsigned int min_timer_period_us = 500;
+unsigned int min_timer_period_us = 200;
 module_param(min_timer_period_us, uint, S_IRUGO | S_IWUSR);
 
 static bool __read_mostly kvmclock_periodic_sync = true;
-- 
2.7.4

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-05-04 12:28 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-04-30  2:38 [PATCH] KVM: X86: Limit timer frequency with more smaller interval Wanpeng Li
2018-04-30 12:31 ` Darren Kenny
2018-05-04 12:28 ` Wanpeng Li

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).