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From: Paolo Bonzini <pbonzini@redhat.com>
To: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>,
	Sergio Lopez <slp@redhat.com>,
	qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] QEMU event loop optimizations
Date: Tue, 2 Apr 2019 18:25:04 +0200	[thread overview]
Message-ID: <b4f5997d-e42a-aaaa-e145-b55d5f6efd93@redhat.com> (raw)
In-Reply-To: <20190402161853.GE5352@localhost.localdomain>

On 02/04/19 18:18, Kevin Wolf wrote:
> Am 26.03.2019 um 15:11 hat Paolo Bonzini geschrieben:
>> - but actually (and a precursor to using IOCB_CMD_POLL) it should be
>> possible to have just one LinuxAioState per AioContext, and then
>> it can simply share the AioContext's EventNotifier.  This removes
>> the need to do the event_notifier_test_and_clear in linux-aio.c.
> 
> Isn't having only one LinuxAioState per AioContext what we already do?
> See aio_get_linux_aio().

And I should have known that:

    commit 0187f5c9cb172771ba85c66e3bf61f8cde6d6561
    Author: Paolo Bonzini <pbonzini@redhat.com>
    Date:   Mon Jul 4 18:33:20 2016 +0200

    linux-aio: share one LinuxAioState within an AioContext

    This has better performance because it executes fewer system calls
    and does not use a bottom half per disk.

    Originally proposed by Ming Lei.

The second point, which is to share the AioContext's EventNotifier,
still stands.

Paolo

  reply	other threads:[~2019-04-02 16:37 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20190326131822.GD15011@stefanha-x1.localdomain>
2019-04-05 16:29 ` [Qemu-devel] QEMU event loop optimizations Sergio Lopez
2019-04-05 16:29   ` Sergio Lopez
2019-04-08  8:29   ` Stefan Hajnoczi
2019-04-08  8:29     ` Stefan Hajnoczi
     [not found] ` <55751c00-0854-ea4d-75b5-ab82b4eeb70d@redhat.com>
2019-04-02 16:18   ` Kevin Wolf
2019-04-02 16:25     ` Paolo Bonzini [this message]
2019-04-05 16:33   ` Sergio Lopez
2019-04-05 16:33     ` Sergio Lopez
2019-04-08 10:42     ` Paolo Bonzini
2019-04-08 10:42       ` Paolo Bonzini

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