KVM: X86: Lower the default timer frequency limit to 200us
authorWanpeng Li <wanpengli@tencent.com>
Sat, 5 May 2018 11:02:32 +0000 (04:02 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 20 Jun 2018 19:01:45 +0000 (04:01 +0900)
commitf882b432dd4da459473002dede4632ce24a28999
tree02acb5254472e42d29d35570a27c221b2e6e57e8
parentfca8af7b722dac14b548376c0be8d145695ea336
KVM: X86: Lower the default timer frequency limit to 200us

[ Upstream commit 4c27625b7a67eb9006963ed2bcf8e53b259b43af ]

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.

As suggested by Paolo, lower the default timer frequency limit to a
smaller interval of 200 us (5000 Hz) to leave some headroom. This
is required due to Windows 10 changing 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>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Anthoine Bourgeois <anthoine.bourgeois@blade-group.com>
Cc: Darren Kenny <darren.kenny@oracle.com>
Cc: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/kvm/x86.c