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>, John Snow <jsnow@redhat.com>,
qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>,
Max Reitz <mreitz@redhat.com>
Subject: Re: [PATCH v2 6/7] block-copy: atomic .cancelled and .finished fields in BlockCopyCallState
Date: Fri, 21 May 2021 17:02:26 +0200 [thread overview]
Message-ID: <05e94bee-8ee8-e23f-19c1-a7fcb540e080@redhat.com> (raw)
In-Reply-To: <068832dd-c577-0234-4a1d-dfdae6a5b4dd@virtuozzo.com>
On 20/05/21 17:34, Vladimir Sementsov-Ogievskiy wrote:
>
>> By adding acquire/release pairs, we ensure that .ret and .error_is_read
>> fields are written by block_copy_dirty_clusters before .finished is true.
>
> As I already said, please, can we live with one mutex for now? finished,
> ret, error_is_read, all these variables are changing rarely. I doubt
> that performance is improved by these atomic operations. But complexity
> of the architecture increases exponentially.
The problem is that these are used outside coroutines.
load-acquire/store-release is the simplest way to handle a "finished"
flag really.
Paolo
next prev parent reply other threads:[~2021-05-21 15:03 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-18 10:07 [PATCH v2 0/7] block-copy: protect block-copy internal structures Emanuele Giuseppe Esposito
2021-05-18 10:07 ` [PATCH v2 1/7] block-copy: streamline choice of copy_range vs. read/write Emanuele Giuseppe Esposito
2021-05-20 14:42 ` Vladimir Sementsov-Ogievskiy
2021-05-20 15:06 ` Emanuele Giuseppe Esposito
2021-05-20 15:24 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:10 ` Paolo Bonzini
2021-05-21 15:48 ` Vladimir Sementsov-Ogievskiy
2021-05-21 16:43 ` Paolo Bonzini
2021-05-21 17:51 ` Vladimir Sementsov-Ogievskiy
2021-05-27 8:20 ` Stefan Hajnoczi
2021-05-27 19:04 ` Paolo Bonzini
2021-05-18 10:07 ` [PATCH v2 2/7] block-copy: improve documentation of BlockCopyTask and BlockCopyState types and functions Emanuele Giuseppe Esposito
2021-05-20 15:00 ` Vladimir Sementsov-Ogievskiy
2021-05-20 15:15 ` Emanuele Giuseppe Esposito
2021-05-18 10:07 ` [PATCH v2 3/7] block-copy: move progress_set_remaining in block_copy_task_end Emanuele Giuseppe Esposito
2021-05-20 15:03 ` Vladimir Sementsov-Ogievskiy
2021-05-18 10:07 ` [PATCH v2 4/7] block-copy: add a CoMutex to the BlockCopyTask list Emanuele Giuseppe Esposito
2021-05-20 15:19 ` Vladimir Sementsov-Ogievskiy
2021-05-25 10:07 ` Emanuele Giuseppe Esposito
2021-05-25 10:25 ` Vladimir Sementsov-Ogievskiy
2021-05-26 14:58 ` Paolo Bonzini
2021-05-26 16:13 ` Vladimir Sementsov-Ogievskiy
2021-05-27 9:07 ` Stefan Hajnoczi
2021-05-18 10:07 ` [PATCH v2 5/7] block-copy: add QemuMutex lock for BlockCopyCallState list Emanuele Giuseppe Esposito
2021-05-20 15:30 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:01 ` Paolo Bonzini
2021-05-25 10:58 ` Emanuele Giuseppe Esposito
2021-05-26 14:49 ` Paolo Bonzini
2021-05-28 10:53 ` Paolo Bonzini
2021-05-18 10:07 ` [PATCH v2 6/7] block-copy: atomic .cancelled and .finished fields in BlockCopyCallState Emanuele Giuseppe Esposito
2021-05-20 15:34 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:02 ` Paolo Bonzini [this message]
2021-05-21 15:53 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:56 ` Vladimir Sementsov-Ogievskiy
2021-05-21 16:47 ` Paolo Bonzini
2021-05-18 10:07 ` [PATCH v2 7/7] block-copy: protect BlockCopyState .method fields Emanuele Giuseppe Esposito
2021-05-21 17:10 ` Vladimir Sementsov-Ogievskiy
2021-05-25 10:18 ` Emanuele Giuseppe Esposito
2021-05-25 11:00 ` Vladimir Sementsov-Ogievskiy
2021-05-26 14:48 ` Paolo Bonzini
2021-05-26 17:18 ` Vladimir Sementsov-Ogievskiy
2021-05-28 10:24 ` Paolo Bonzini
2021-05-28 11:01 ` Paolo Bonzini
2021-05-28 11:52 ` Vladimir Sementsov-Ogievskiy
2021-05-28 12:44 ` Vladimir Sementsov-Ogievskiy
2021-05-20 13:47 ` [PATCH v2 0/7] block-copy: protect block-copy internal structures Vladimir Sementsov-Ogievskiy
2021-05-20 14:33 ` Emanuele Giuseppe Esposito
2021-05-27 10:31 ` Stefan Hajnoczi
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