From: Thomas Gleixner <tglx@linutronix.de>
To: Wanpeng Li <kernellwp@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, kvm <kvm@vger.kernel.org>,
Frederic Weisbecker <frederic@kernel.org>
Subject: Re: [PATCH v2] sched/nohz: Optimize get_nohz_timer_target()
Date: Wed, 23 Oct 2019 10:29:12 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1910231028250.2308@nanos.tec.linutronix.de> (raw)
In-Reply-To: <CANRm+CxUpwZ9KwOcQp=Ok64giyjjcJOGb2=zU6vayQzLqYvpXQ@mail.gmail.com>
On Wed, 23 Oct 2019, Wanpeng Li wrote:
> I didn't see your refactor to get_nohz_timer_target() which you
> mentioned in IRC after four months, I can observe cyclictest drop from
> 4~5us to 8us in kvm guest(we offload the lapic timer emulation to
> housekeeping cpu to avoid timer fire external interrupt on the pCPU
> which vCPU resident incur a vCPU vmexit) w/o this patch in the case of
> there is no busy housekeeping cpu. The score can be recovered after I
> give stress to create a busy housekeeping cpu.
>
> Could you consider applying this patch for temporary since I'm not
> sure when the refactor can be ready.
Yeah. It's delayed (again).... Will pick that up.
Thanks,
tglx
next prev parent reply other threads:[~2019-10-23 8:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1561682593-12071-1-git-send-email-wanpengli@tencent.com>
[not found] ` <20190628011012.GA19488@lerouge>
2019-10-23 8:16 ` [PATCH v2] sched/nohz: Optimize get_nohz_timer_target() Wanpeng Li
2019-10-23 8:29 ` Thomas Gleixner [this message]
2019-10-23 9:25 ` Wanpeng Li
2020-01-06 6:21 ` Wanpeng Li
2020-01-10 14:12 ` Thomas Gleixner
2020-01-13 1:32 ` Wanpeng Li
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.DEB.2.21.1910231028250.2308@nanos.tec.linutronix.de \
--to=tglx@linutronix.de \
--cc=frederic@kernel.org \
--cc=kernellwp@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).