From: Andi Kleen <andi@firstfloor.org>
To: Yang Zhang <yang.zhang.wz@gmail.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
wanpeng.li@hotmail.com, mst@redhat.com, pbonzini@redhat.com,
tglx@linutronix.de, rkrcmar@redhat.com, dmatlack@google.com,
agraf@suse.de, peterz@infradead.org, linux-doc@vger.kernel.org
Subject: Re: [RFC PATCH v2 0/7] x86/idle: add halt poll support
Date: Tue, 29 Aug 2017 06:03:26 -0700 [thread overview]
Message-ID: <87bmmyedb5.fsf@firstfloor.org> (raw)
In-Reply-To: <1504007201-12904-1-git-send-email-yang.zhang.wz@gmail.com> (Yang Zhang's message of "Tue, 29 Aug 2017 11:46:34 +0000")
Yang Zhang <yang.zhang.wz@gmail.com> writes:
> Some latency-intensive workload will see obviously performance
> drop when running inside VM. The main reason is that the overhead
> is amplified when running inside VM. The most cost i have seen is
> inside idle path.
You could test with https://lkml.org/lkml/2017/7/9/204
which optimizes these idle paths with a fast path.
If that works it would be a far better solution than
explicit tunables and basically giving up by polling.
-Andi
next prev parent reply other threads:[~2017-08-29 13:03 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-29 11:46 [RFC PATCH v2 0/7] x86/idle: add halt poll support Yang Zhang
2017-08-29 11:46 ` [RFC PATCH v2 1/7] x86/paravirt: Add pv_idle_ops to paravirt ops Yang Zhang
2017-08-29 11:46 ` Yang Zhang
2017-08-29 13:55 ` Konrad Rzeszutek Wilk
2017-08-29 13:55 ` Konrad Rzeszutek Wilk
2017-08-30 7:33 ` Juergen Gross
2017-08-30 7:33 ` Juergen Gross
2017-09-01 6:50 ` Yang Zhang
2017-09-01 6:50 ` Yang Zhang
2017-08-29 11:46 ` [RFC PATCH v2 2/7] KVM guest: register kvm_idle_poll for pv_idle_ops Yang Zhang
2017-08-29 11:46 ` [RFC PATCH v2 3/7] sched/idle: Add poll before enter real idle path Yang Zhang
2017-08-29 12:45 ` Peter Zijlstra
2017-09-01 5:57 ` Quan Xu
2017-09-14 8:41 ` Quan Xu
2017-09-14 9:18 ` Borislav Petkov
2017-08-29 14:39 ` Borislav Petkov
2017-09-01 6:49 ` Quan Xu
2017-09-29 10:39 ` Quan Xu
2017-08-29 11:46 ` [RFC PATCH v2 4/7] x86/paravirt: Add update in x86/paravirt pv_idle_ops Yang Zhang
2017-08-29 11:46 ` Yang Zhang
2017-08-29 11:46 ` [RFC PATCH v2 5/7] Documentation: Add three sysctls for smart idle poll Yang Zhang
2017-08-29 11:46 ` Yang Zhang
2017-08-29 11:46 ` Yang Zhang
2017-08-29 17:20 ` Luis R. Rodriguez
2017-08-29 17:20 ` Luis R. Rodriguez
2017-08-29 17:20 ` Luis R. Rodriguez
2017-08-29 11:46 ` [RFC PATCH v2 6/7] KVM guest: introduce smart idle poll algorithm Yang Zhang
2017-08-29 11:46 ` [RFC PATCH v2 7/7] sched/idle: update poll time when wakeup from idle Yang Zhang
2017-08-29 12:46 ` Peter Zijlstra
2017-09-01 7:30 ` Yang Zhang
2017-09-29 10:29 ` Quan Xu
2017-08-29 11:58 ` [RFC PATCH v2 0/7] x86/idle: add halt poll support Alexander Graf
2017-09-01 6:21 ` Yang Zhang
2017-08-29 13:03 ` Andi Kleen [this message]
2017-08-29 14:02 ` Wanpeng Li
2017-08-29 14:27 ` Konrad Rzeszutek Wilk
2017-08-29 14:36 ` Michael S. Tsirkin
2017-09-01 6:32 ` Yang Zhang
2017-09-01 6:52 ` Wanpeng Li
2017-09-01 6:44 ` Yang Zhang
2017-09-01 6:58 ` Wanpeng Li
2017-09-01 7:53 ` Yang Zhang
2017-08-29 14:56 ` Michael S. Tsirkin
2017-09-13 11:56 ` Yang Zhang
2017-09-14 8:36 ` Quan Xu
2017-09-14 9:19 ` Wanpeng Li
2017-09-14 9:40 ` Quan Xu
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