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 v4 6/6] block-copy: atomic .cancelled and .finished fields in BlockCopyCallState
Date: Tue, 22 Jun 2021 12:20:03 +0200 [thread overview]
Message-ID: <c8b4e9b9-15a6-3ae4-cb8f-5289a221dcbe@redhat.com> (raw)
In-Reply-To: <28d4cd1c-2495-b30d-3c9f-2d8d0d3e897b@virtuozzo.com>
On 22/06/21 11:36, Vladimir Sementsov-Ogievskiy wrote:
>> It does. If it returns true, you still want the load of finished to
>> happen before the reads that follow.
>
> Hmm.. The worst case if we use just qatomic_read is that assertion will
> not crash when it actually should. That doesn't break the logic. But
> that's not good anyway.
>
> OK, I agree, let's keep it.
You can also have a finished job, but get a stale value for
error_is_read or ret. The issue is not in getting the stale value per
se, but in block_copy_call_status's caller not expecting it.
(I understand you agree, but I guess it can be interesting to learn
about this too).
Paolo
next prev parent reply other threads:[~2021-06-22 10:34 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-14 7:33 [PATCH v4 0/6] block-copy: protect block-copy internal structures Emanuele Giuseppe Esposito
2021-06-14 7:33 ` [PATCH v4 1/6] block-copy: small refactor in block_copy_task_entry and block_copy_common Emanuele Giuseppe Esposito
2021-06-19 14:33 ` Vladimir Sementsov-Ogievskiy
2021-06-14 7:33 ` [PATCH v4 2/6] block-copy: streamline choice of copy_range vs. read/write Emanuele Giuseppe Esposito
2021-06-19 15:05 ` Vladimir Sementsov-Ogievskiy
2021-06-19 18:23 ` Vladimir Sementsov-Ogievskiy
2021-06-14 7:33 ` [PATCH v4 3/6] block-copy: improve comments of BlockCopyTask and BlockCopyState types and functions Emanuele Giuseppe Esposito
2021-06-19 15:23 ` Vladimir Sementsov-Ogievskiy
2021-06-19 18:31 ` Vladimir Sementsov-Ogievskiy
2021-06-21 8:13 ` Emanuele Giuseppe Esposito
2021-06-22 9:20 ` Vladimir Sementsov-Ogievskiy
2021-06-21 7:59 ` Emanuele Giuseppe Esposito
2021-06-22 9:16 ` Vladimir Sementsov-Ogievskiy
2021-06-19 17:27 ` Vladimir Sementsov-Ogievskiy
2021-06-21 8:21 ` Emanuele Giuseppe Esposito
2021-06-19 18:53 ` Vladimir Sementsov-Ogievskiy
2021-06-21 8:28 ` Emanuele Giuseppe Esposito
2021-06-14 7:33 ` [PATCH v4 4/6] block-copy: move progress_set_remaining in block_copy_task_end Emanuele Giuseppe Esposito
2021-06-14 7:33 ` [PATCH v4 5/6] block-copy: add a CoMutex Emanuele Giuseppe Esposito
2021-06-19 19:34 ` Vladimir Sementsov-Ogievskiy
2021-06-14 7:33 ` [PATCH v4 6/6] block-copy: atomic .cancelled and .finished fields in BlockCopyCallState Emanuele Giuseppe Esposito
2021-06-19 20:06 ` Vladimir Sementsov-Ogievskiy
2021-06-21 9:30 ` Emanuele Giuseppe Esposito
2021-06-22 9:56 ` Vladimir Sementsov-Ogievskiy
2021-06-22 8:15 ` Paolo Bonzini
2021-06-22 9:36 ` Vladimir Sementsov-Ogievskiy
2021-06-22 10:20 ` Paolo Bonzini [this message]
2021-06-22 10:39 ` Vladimir Sementsov-Ogievskiy
2021-06-22 20:57 ` Emanuele Giuseppe Esposito
2021-06-23 10:06 ` Paolo Bonzini
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=c8b4e9b9-15a6-3ae4-cb8f-5289a221dcbe@redhat.com \
--to=pbonzini@redhat.com \
--cc=eesposit@redhat.com \
--cc=jsnow@redhat.com \
--cc=kwolf@redhat.com \
--cc=mreitz@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@redhat.com \
--cc=vsementsov@virtuozzo.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).