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From: Wanpeng Li <kernellwp@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>, kvm <kvm@vger.kernel.org>
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Anthoine Bourgeois" <anthoine.bourgeois@blade-group.com>
Subject: Re: [PATCH] KVM: X86: Limit timer frequency with more smaller interval
Date: Fri, 4 May 2018 20:28:30 +0800	[thread overview]
Message-ID: <CANRm+CxuzHjfFPapQbPGBLN78nt=e4T4z5D0NJYrQ_EzrQdOMQ@mail.gmail.com> (raw)
In-Reply-To: <1525055900-20729-1-git-send-email-wanpengli@tencent.com>

ping,
2018-04-30 10:38 GMT+08:00 Wanpeng Li <kernellwp@gmail.com>:
> 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
>

      parent reply	other threads:[~2018-05-04 12:28 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-30  2:38 Wanpeng Li
2018-04-30 12:31 ` Darren Kenny
2018-05-04 12:28 ` Wanpeng Li [this message]

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