From: Paolo Bonzini <pbonzini@redhat.com>
To: Kevin Wolf <kwolf@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Cc: "qemu-block@nongnu.org" <qemu-block@nongnu.org>,
"mreitz@redhat.com" <mreitz@redhat.com>,
"eblake@redhat.com" <eblake@redhat.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH] file-posix: Cache lseek result for data regions
Date: Fri, 25 Jan 2019 11:10:56 +0100 [thread overview]
Message-ID: <3cf90de9-5fc5-c24c-b232-bd0f564202a9@redhat.com> (raw)
In-Reply-To: <20190124154248.GK4601@localhost.localdomain>
On 24/01/19 16:42, Kevin Wolf wrote:
>> Recently Paolo asked me not to add more users of AioContext lock. Unfortunately
>> I don't understand the whole picture around it.. Doesn't this apply here?
>> https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg03410.html
> I don't know. Honestly I feel nobody except Paolo knows, because we
> don't know his patches yet.
This is true. On the other hand, the AioContext lock is only used in
some special cases around block jobs and blk_set_aio_context, and in
general the block devices already should not have any dependencies
(unless they crept in without me noticing).
In particular...
> But raw doesn't have an s->lock yet, so I
> think removing the AioContext lock involves some work on it anyway and
> adding this doesn't really change the amount of work.
... BDRVRawState doesn't have any data that changes after open, does it?
This is why it doesn't have an s->lock.
Paolo
next prev parent reply other threads:[~2019-01-25 10:11 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-24 14:17 [Qemu-devel] [PATCH] file-posix: Cache lseek result for data regions Kevin Wolf
2019-01-24 14:40 ` Vladimir Sementsov-Ogievskiy
2019-01-24 15:11 ` Kevin Wolf
2019-01-24 15:22 ` Vladimir Sementsov-Ogievskiy
2019-01-24 15:42 ` Kevin Wolf
2019-01-25 10:10 ` Paolo Bonzini [this message]
2019-01-25 10:30 ` Kevin Wolf
2019-02-04 10:17 ` Paolo Bonzini
2019-01-24 15:56 ` Eric Blake
2019-01-29 10:56 ` Kevin Wolf
2019-01-29 21:03 ` Eric Blake
2019-01-24 16:18 ` Vladimir Sementsov-Ogievskiy
2019-01-24 16:36 ` Kevin Wolf
2019-01-25 9:13 ` Vladimir Sementsov-Ogievskiy
2019-01-25 13:26 ` Eric Blake
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