From: Takuya Yoshikawa <takuya.yoshikawa@gmail.com>
To: Avi Kivity <avi@redhat.com>
Cc: mtosatti@redhat.com, kvm@vger.kernel.org, yoshikawa.takuya@oss.ntt.co.jp
Subject: Re: [PATCH 1/1 v2] KVM: Reduce mmu_lock contention during dirty logging by cond_resched()
Date: Mon, 30 Apr 2012 23:06:41 +0900 [thread overview]
Message-ID: <20120430230641.2fc14229760684d936d7ef58@gmail.com> (raw)
In-Reply-To: <4F9D5C45.3070801@redhat.com>
On Sun, 29 Apr 2012 18:20:37 +0300
Avi Kivity <avi@redhat.com> wrote:
> > - cond_resched_lock() uses spin_needbreak(), and I am not sure if
> > this still does rescheduling for alleviating mmu_lock contention
> > without CONFIG_PREEMPT.
>
> IMO that's a feature. If kernel policy is not to lockbreak when
> !CONFIG_PREEMPT, then we should follow it, whether it's the right thing
> or not. If it's the wrong thing, change it in the kernel proper.
Agreed.
Anyway, we need to alleviate mmu_lock contention on server machines, where we
usually do not select CONFIG_PREEMPT.
So I need to check the porpose of this API.
> while (1)
> need_to_read_the_code_a_bit_more();
It's a pleasure!
Thanks,
Takuya
next prev parent reply other threads:[~2012-04-30 14:06 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-28 10:05 [PATCH 0/1 v2] KVM: Alleviate mmu_lock contention during dirty logging Takuya Yoshikawa
2012-04-28 10:07 ` [PATCH 1/1 v2] KVM: Reduce mmu_lock contention during dirty logging by cond_resched() Takuya Yoshikawa
2012-04-29 11:27 ` Avi Kivity
2012-04-29 12:17 ` Takuya Yoshikawa
2012-04-29 12:59 ` Avi Kivity
2012-04-29 14:24 ` Takuya Yoshikawa
2012-04-29 14:39 ` Avi Kivity
2012-04-29 14:55 ` Takuya Yoshikawa
2012-04-29 15:00 ` Avi Kivity
2012-04-29 15:13 ` Takuya Yoshikawa
2012-04-29 15:20 ` Avi Kivity
2012-04-30 14:06 ` Takuya Yoshikawa [this message]
2012-05-01 3:04 ` Marcelo Tosatti
2012-05-01 13:14 ` Takuya Yoshikawa
2012-05-01 3:07 ` Marcelo Tosatti
2012-05-02 11:24 ` Heavy memory_region_get_dirty() -- Re: [PATCH 0/1 v2] KVM: Alleviate mmu_lock contention during dirty logging Takuya Yoshikawa
2012-05-02 11:33 ` Avi Kivity
2012-05-02 14:20 ` Takuya Yoshikawa
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