From: Ralph Corderoy <ralph@inputplus.co.uk>
To: Matthew Wilcox <willy@infradead.org>
Cc: Nate Karstens <nate.karstens@garmin.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jeff Layton <jlayton@kernel.org>,
"J. Bruce Fields" <bfields@fieldses.org>,
Arnd Bergmann <arnd@arndb.de>,
Richard Henderson <rth@twiddle.net>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Matt Turner <mattst88@gmail.com>,
"James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
Helge Deller <deller@gmx.de>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Eric Dumazet <edumazet@google.com>,
David Laight <David.Laight@aculab.com>,
linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-alpha@vger.kernel.org, linux-parisc@vger.kernel.org,
sparclinux@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, Changli Gao <xiaosuo@gmail.com>
Subject: Re: [PATCH v2] Implement close-on-fork
Date: Sun, 19 Jun 2022 11:42:28 +0100 [thread overview]
Message-ID: <20220619104228.A9789201F7@orac.inputplus.co.uk> (raw)
In-Reply-To: <Yq4qIxh5QnhQZ0SJ@casper.infradead.org>
Hi Matthew, thanks for replying.
> > The need for O_CLOFORK might be made more clear by looking at a
> > long-standing Go issue, i.e. unrelated to system(3), which was started
> > in 2017 by Russ Cox when he summed up the current race-condition
> > behaviour of trying to execve(2) a newly created file:
> > https://github.com/golang/go/issues/22315.
>
> The problem is that people advocating for O_CLOFORK understand its
> value, but not its cost. Other google employees have a system which
> has literally millions of file descriptors in a single process.
> Having to maintain this extra state per-fd is a cost they don't want
> to pay (and have been quite vocal about earlier in this thread).
So do you agree the userspace issue is best solved by *_CLOFORK and the
problem is how to implement *_CLOFORK at an acceptable cost?
OTOH David Laight was making suggestions on moving the load to the
fork/exec path earlier in the thread, but OTOH Al Viro mentioned a
‘portable solution’, though that could have been to a specific issue
rather than the more general case.
How would you recommend approaching an acceptable cost is progressed?
Iterate on patch versions? Open a bugzilla.kernel.org for central
tracking and linking from the other projects? ..?
--
Cheers, Ralph.
next prev parent reply other threads:[~2022-06-19 10:42 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-15 15:23 [PATCH v2] Implement close-on-fork Nate Karstens
2020-05-15 15:23 ` [PATCH v2 1/4] fs: " Nate Karstens
2020-05-15 15:23 ` [PATCH v2 2/4] fs: Add O_CLOFORK flag for open(2) and dup3(2) Nate Karstens
2020-05-15 15:23 ` [PATCH v2 3/4] fs: Add F_DUPFD_CLOFORK to fcntl(2) Nate Karstens
2020-05-15 15:23 ` [PATCH v2 4/4] net: Add SOCK_CLOFORK Nate Karstens
2020-05-15 15:30 ` [PATCH v2] Implement close-on-fork Eric Dumazet
2020-05-15 15:59 ` David Laight
2020-05-15 15:57 ` Matthew Wilcox
2020-05-15 16:07 ` Karstens, Nate
2020-05-15 16:25 ` James Bottomley
2020-05-15 18:28 ` Karstens, Nate
2020-05-15 18:43 ` Matthew Wilcox
2020-05-25 8:16 ` Pavel Machek
2020-05-15 16:26 ` Matthew Wilcox
2020-05-16 13:29 ` Christian Brauner
2020-05-15 16:03 ` Al Viro
2020-05-15 16:26 ` Karstens, Nate
2020-05-15 16:53 ` David Howells
2022-06-18 11:41 ` Ralph Corderoy
2022-06-18 19:40 ` Matthew Wilcox
2022-06-19 10:42 ` Ralph Corderoy [this message]
2022-06-28 13:13 ` Christian Brauner
2022-06-28 13:38 ` David Laight
2022-06-28 13:43 ` Christian Brauner
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