From: Nick Piggin <npiggin@gmail.com>
To: Jeff Moyer <jmoyer@redhat.com>
Cc: Jan Kara <jack@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-kernel@vger.kernel.org,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: [patch] fs: aio fix rcu lookup
Date: Thu, 20 Jan 2011 07:18:53 +1100 [thread overview]
Message-ID: <AANLkTiniSG3tfXx1iUtzf53sSsr=R6pmvmWrSV8FiYE9@mail.gmail.com> (raw)
In-Reply-To: <x49aaiwd6cs.fsf@segfault.boston.devel.redhat.com>
On Thu, Jan 20, 2011 at 6:46 AM, Jeff Moyer <jmoyer@redhat.com> wrote:
> Jeff Moyer <jmoyer@redhat.com> writes:
>
>> Jan Kara <jack@suse.cz> writes:
>>
>>> But there's the second race I describe making it possible
>>> for new IO to be created after io_destroy() has waited for all IO to
>>> finish...
>>
>> Can't that be solved by introducing memory barriers around the accesses
>> to ->dead?
>
> Upon further consideration, I don't think so.
>
> Given the options, I think adding the synchronize rcu to the io_destroy
> path is the best way forward. You're already waiting for a bunch of
> queued I/O to finish, so there is no guarantee that you're going to
> finish that call quickly.
I think synchronize_rcu() is not something to sprinkle around outside
very slow paths. It can be done without synchronize_rcu.
next prev parent reply other threads:[~2011-01-19 20:18 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-14 1:35 [patch] fs: aio fix rcu lookup Nick Piggin
2011-01-14 14:52 ` Jeff Moyer
2011-01-14 15:00 ` Nick Piggin
2011-01-17 19:07 ` Jeff Moyer
2011-01-17 23:24 ` Nick Piggin
2011-01-18 17:21 ` Jeff Moyer
2011-01-18 19:01 ` Jan Kara
2011-01-18 22:17 ` Nick Piggin
2011-01-18 23:00 ` Jeff Moyer
2011-01-18 23:05 ` Nick Piggin
2011-01-18 23:52 ` Jan Kara
2011-01-19 0:20 ` Nick Piggin
2011-01-19 13:21 ` Jan Kara
2011-01-19 16:03 ` Nick Piggin
2011-01-19 16:50 ` Jan Kara
2011-01-19 17:37 ` Nick Piggin
2011-01-20 20:21 ` Jan Kara
2011-01-19 19:13 ` Jeff Moyer
2011-01-19 19:46 ` Jeff Moyer
2011-01-19 20:18 ` Nick Piggin [this message]
2011-01-19 20:32 ` Jeff Moyer
2011-01-19 20:45 ` Nick Piggin
2011-01-19 21:03 ` Jeff Moyer
2011-01-19 21:20 ` Nick Piggin
2011-01-20 4:03 ` Paul E. McKenney
2011-01-20 18:31 ` Nick Piggin
2011-01-20 20:02 ` Paul E. McKenney
2011-01-20 20:15 ` Eric Dumazet
2011-01-21 21:22 ` Paul E. McKenney
2011-01-20 20:16 ` Jan Kara
2011-01-20 21:16 ` Jeff Moyer
2011-02-01 16:24 ` Jan Kara
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='AANLkTiniSG3tfXx1iUtzf53sSsr=R6pmvmWrSV8FiYE9@mail.gmail.com' \
--to=npiggin@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=jack@suse.cz \
--cc=jmoyer@redhat.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=paulmck@linux.vnet.ibm.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).