qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Kevin Wolf <kwolf@redhat.com>
To: Zhenyu Ye <yezhenyu2@huawei.com>
Cc: fam@euphon.net, qemu-block@nongnu.org, armbru@redhat.com,
	xiexiangyou@huawei.com, qemu-devel@nongnu.org,
	stefanha@redhat.com, pbonzini@redhat.com, mreitz@redhat.com
Subject: Re: [PATCH v1 0/2] Add timeout mechanism to qmp actions
Date: Mon, 10 Aug 2020 17:38:11 +0200	[thread overview]
Message-ID: <20200810153811.GF14538@linux.fritz.box> (raw)
In-Reply-To: <20200810145246.1049-1-yezhenyu2@huawei.com>

Am 10.08.2020 um 16:52 hat Zhenyu Ye geschrieben:
> Before doing qmp actions, we need to lock the qemu_global_mutex,
> so the qmp actions should not take too long time.
> 
> Unfortunately, some qmp actions need to acquire aio context and
> this may take a long time.  The vm will soft lockup if this time
> is too long.

Do you have a specific situation in mind where getting the lock of an
AioContext can take a long time? I know that the main thread can
block for considerable time, but QMP commands run in the main thread, so
this patch doesn't change anything for this case. It would be effective
if an iothread blocks, but shouldn't everything running in an iothread
be asynchronous and therefore keep the AioContext lock only for a short
time?

Kevin



  parent reply	other threads:[~2020-08-10 15:39 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-10 14:52 [PATCH v1 0/2] Add timeout mechanism to qmp actions Zhenyu Ye
2020-08-10 14:52 ` [PATCH v1 1/2] util: introduce aio_context_acquire_timeout Zhenyu Ye
2020-08-10 14:52 ` [PATCH v1 2/2] qmp: use aio_context_acquire_timeout replace aio_context_acquire Zhenyu Ye
2020-08-10 15:38 ` Kevin Wolf [this message]
2020-08-11 13:54   ` [PATCH v1 0/2] Add timeout mechanism to qmp actions Zhenyu Ye
2020-08-21 12:52     ` Stefan Hajnoczi
2020-09-14 13:27     ` Stefan Hajnoczi
2020-09-17  7:36       ` Zhenyu Ye
2020-09-17 10:10         ` Fam Zheng
2020-09-17 15:44         ` Stefan Hajnoczi
2020-09-17 16:01           ` Fam Zheng
2020-09-18 11:23             ` Zhenyu Ye
2020-09-18 14:06               ` Fam Zheng
2020-09-19  2:22                 ` Zhenyu Ye
2020-09-21 11:14                   ` Fam Zheng
2020-10-13 10:00                     ` Stefan Hajnoczi
2020-10-19 12:40                       ` Zhenyu Ye
2020-10-19 13:25                         ` Paolo Bonzini
2020-10-20  1:34                           ` Zhenyu Ye
2020-10-22 16:29                             ` Fam Zheng
2020-12-08 13:10                               ` Stefan Hajnoczi
2020-12-08 13:47                                 ` Glauber Costa
2020-12-14 16:33                                   ` Stefan Hajnoczi
2020-12-21 11:30                                     ` Zhenyu Ye
2020-09-14 14:42     ` Daniel P. Berrangé
2020-09-17  8:12       ` Zhenyu Ye
2020-08-12 13:51 ` Stefan Hajnoczi
2020-08-13  1:51   ` Zhenyu Ye

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=20200810153811.GF14538@linux.fritz.box \
    --to=kwolf@redhat.com \
    --cc=armbru@redhat.com \
    --cc=fam@euphon.net \
    --cc=mreitz@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=qemu-block@nongnu.org \
    --cc=qemu-devel@nongnu.org \
    --cc=stefanha@redhat.com \
    --cc=xiexiangyou@huawei.com \
    --cc=yezhenyu2@huawei.com \
    /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).