From: Kevin Wolf <kwolf@redhat.com>
To: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "keith.busch@intel.com" <keith.busch@intel.com>,
"jsnow@redhat.com" <jsnow@redhat.com>,
"qemu-block@nongnu.org" <qemu-block@nongnu.org>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"mreitz@redhat.com" <mreitz@redhat.com>,
"stefanha@redhat.com" <stefanha@redhat.com>,
Denis Lunev <den@virtuozzo.com>,
"famz@redhat.com" <famz@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Subject: Re: [Qemu-devel] [PATCH] blk: postpone request execution on a context protected with "drained section"
Date: Mon, 10 Dec 2018 13:25:17 +0100 [thread overview]
Message-ID: <20181210122517.GD5000@localhost.localdomain> (raw)
In-Reply-To: <01597daf-b1b8-d506-85c1-b58af758f367@virtuozzo.com>
Am 10.12.2018 um 13:14 hat Denis Plotnikov geschrieben:
> >> @@ -491,9 +506,17 @@ int64_t aio_compute_timeout(AioContext *ctx);
> >> */
> >> static inline void aio_disable_external(AioContext *ctx)
> >> {
> >> + aio_context_acquire(ctx);
> >> atomic_inc(&ctx->external_disable_cnt);
> >> + aio_context_release(ctx);
> >> }
> >
> > This acquire/release pair looks rather useless?
>
> I'm not sure that I understand everything correctly...
> but can a thread (context) try to disable external in another context?
Yes, that can happen. For example, think of bdrv_drain_all().
Kevin
next prev parent reply other threads:[~2018-12-10 12:26 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-05 12:23 [Qemu-devel] [PATCH] blk: postpone request execution on a context protected with "drained section" Denis Plotnikov
2018-12-07 12:26 ` Kevin Wolf
2018-12-10 12:14 ` Denis Plotnikov
2018-12-10 12:25 ` Kevin Wolf [this message]
2018-12-11 16:55 ` Denis Plotnikov
2018-12-12 12:24 ` Kevin Wolf
2018-12-13 11:07 ` Denis Plotnikov
2018-12-13 12:20 ` Kevin Wolf
2018-12-14 11:54 ` Denis Plotnikov
2018-12-18 8:53 ` Denis Plotnikov
2019-01-09 8:18 ` Denis Plotnikov
2019-01-15 7:22 ` Denis Plotnikov
2019-01-17 12:57 ` [Qemu-devel] PING: " Denis Plotnikov
2019-01-17 14:23 ` Kevin Wolf
2019-01-18 7:43 ` Denis Plotnikov
[not found] ` <20190313160412.GF5167@linux.fritz.box>
2019-04-02 8:35 ` [Qemu-devel] " Denis Plotnikov
2019-04-09 10:01 ` Kevin Wolf
2019-04-09 10:01 ` Kevin Wolf
2019-06-21 9:16 ` [Qemu-devel] [Qemu-block] " Kevin Wolf
2019-06-21 9:59 ` Vladimir Sementsov-Ogievskiy
2019-06-24 9:46 ` Denis Plotnikov
2019-06-26 8:46 ` Denis Plotnikov
2019-06-28 12:32 ` Kevin Wolf
2019-07-02 14:41 ` Denis Plotnikov
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