From: Paolo Bonzini <pbonzini@redhat.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
Emanuele Giuseppe Esposito <eesposit@redhat.com>,
qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
qemu-devel@nongnu.org, Max Reitz <mreitz@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
"Denis V. Lunev" <den@openvz.org>, John Snow <jsnow@redhat.com>
Subject: Re: [PATCH 6/6] aiopool: protect with a mutex
Date: Tue, 11 May 2021 10:34:12 +0200 [thread overview]
Message-ID: <b77ec798-3af7-c0e8-ade1-0b13d745908b@redhat.com> (raw)
In-Reply-To: <bb9be29f-a3ef-3869-ba6f-20a7acc1fe2a@virtuozzo.com>
On 10/05/21 13:56, Vladimir Sementsov-Ogievskiy wrote:
>>
>> + }
>> - if (task->ret < 0 && pool->status == 0) {
>> - pool->status = task->ret;
>> + if (ret < 0) {
>> + qatomic_cmpxchg(&pool->status, 0, ret);
>> }
>
> Can we just do it inside critical section above and avoid extra cmpxchg?
> We'll need just qatomic_set as a pair to qatomic_read()
Good idea.
>> g_free(task);
>> - if (pool->waiting) {
>> - pool->waiting = false;
>> - aio_co_wake(pool->main_co);
>> - }
>> + qemu_co_queue_next(&pool->queue);
>
> this call doesn't need mutex protection?
It does indeed.
I second the idea of "stealing" Denis's two patches to block/aio_task
and only adding the mutex (plus qatomic_read/set) here.
Paolo
> Then we should modify comment
> insid AioTaskPool structure.
>
> Anyway, I think it's simpler to just have one QEMU_MUTEX_GUARD() for the
> whole function.
next prev parent reply other threads:[~2021-05-11 9:13 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-10 8:59 [PATCH 0/6] block-copy: make helper APIs thread safe Emanuele Giuseppe Esposito
2021-05-10 8:59 ` [PATCH 1/6] ratelimit: treat zero speed as unlimited Emanuele Giuseppe Esposito
2021-05-10 11:00 ` Vladimir Sementsov-Ogievskiy
2021-05-10 8:59 ` [PATCH 2/6] block-copy: let ratelimit handle a speed of 0 Emanuele Giuseppe Esposito
2021-05-10 11:06 ` Vladimir Sementsov-Ogievskiy
2021-05-10 8:59 ` [PATCH 3/6] blockjob: " Emanuele Giuseppe Esposito
2021-05-10 11:17 ` Vladimir Sementsov-Ogievskiy
2021-05-10 8:59 ` [PATCH 4/6] progressmeter: protect with a mutex Emanuele Giuseppe Esposito
2021-05-10 11:28 ` Vladimir Sementsov-Ogievskiy
2021-05-10 16:52 ` Emanuele Giuseppe Esposito
2021-05-10 17:17 ` Vladimir Sementsov-Ogievskiy
2021-05-10 17:57 ` Emanuele Giuseppe Esposito
2021-05-11 12:28 ` Paolo Bonzini
2021-05-12 7:09 ` Vladimir Sementsov-Ogievskiy
2021-05-12 15:53 ` Stefan Hajnoczi
2021-05-10 8:59 ` [PATCH 5/6] co-shared-resource: " Emanuele Giuseppe Esposito
2021-05-10 11:40 ` Vladimir Sementsov-Ogievskiy
2021-05-11 8:34 ` Paolo Bonzini
2021-05-12 15:44 ` Stefan Hajnoczi
2021-05-12 18:30 ` Paolo Bonzini
2021-05-14 14:10 ` Emanuele Giuseppe Esposito
2021-05-14 14:26 ` Vladimir Sementsov-Ogievskiy via
2021-05-14 14:32 ` Emanuele Giuseppe Esposito
2021-05-14 15:30 ` Vladimir Sementsov-Ogievskiy via
2021-05-14 17:28 ` Emanuele Giuseppe Esposito
2021-05-14 21:15 ` Vladimir Sementsov-Ogievskiy via
2021-05-14 21:53 ` Emanuele Giuseppe Esposito
2021-05-15 7:11 ` Vladimir Sementsov-Ogievskiy via
2021-05-14 17:55 ` Paolo Bonzini
2021-05-10 8:59 ` [PATCH 6/6] aiopool: " Emanuele Giuseppe Esposito
2021-05-10 11:56 ` Vladimir Sementsov-Ogievskiy
2021-05-11 8:34 ` Paolo Bonzini [this message]
2021-05-12 15:19 ` Stefan Hajnoczi
2021-05-10 10:55 ` [PATCH 0/6] block-copy: make helper APIs thread safe Vladimir Sementsov-Ogievskiy
2021-05-12 14:24 ` Stefan Hajnoczi
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