From: Christoph Hellwig <hch@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Christoph Hellwig <hch@infradead.org>,
Miklos Szeredi <miklos@szeredi.hu>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
mgorman@suse.de, gregkh@suse.de, akpm@linux-foundation.org,
david@fromorbit.com
Subject: Re: [RFC PATCH] shrink_dcache_parent() deadlock
Date: Mon, 9 Jan 2012 14:04:50 -0500 [thread overview]
Message-ID: <20120109190450.GA26390@infradead.org> (raw)
In-Reply-To: <CA+55aFxRroO0KAz8qbhz_2vDc=bc-C2b0ux0tdFfQhBGMnqRzQ@mail.gmail.com>
On Mon, Jan 09, 2012 at 10:46:22AM -0800, Linus Torvalds wrote:
> On Mon, Jan 9, 2012 at 10:30 AM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > Here's a TOTALLY UNTESTED rebase of just that single patch from Dave.
>
> Well, it boots, and the dentry cache shrinks under memory pressure. So
> it's not _totally_ untested now.
>
> But I don't really see why it would fix Miklos' case. I think
> select_parent() may still end up touching the d_lru list of something
> that is on the 'dispose' list. So the patch looks like a nice cleanup,
> but it seems to be independent of the issue Miklos found.
>
> What am I missing now?
After Dave's patch select_parent isolates dentries that are going to
be dropped directly to an on-stack list instead of abusing the LRU.
With that scheme the trylock and retry loop in __shrink_dcache_sb
goes away completely for this caller.
next prev parent reply other threads:[~2012-01-09 19:04 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-09 10:58 [RFC PATCH] shrink_dcache_parent() deadlock Miklos Szeredi
2012-01-09 16:43 ` Linus Torvalds
2012-01-09 17:05 ` Miklos Szeredi
2012-01-09 17:16 ` Greg KH
2012-01-09 17:16 ` Christoph Hellwig
2012-01-09 17:30 ` Al Viro
2012-01-09 18:30 ` Linus Torvalds
2012-01-09 18:46 ` Linus Torvalds
2012-01-09 19:04 ` Christoph Hellwig [this message]
2012-01-09 19:18 ` Linus Torvalds
2012-01-09 20:59 ` Dave Chinner
2012-01-09 21:21 ` Linus Torvalds
2012-01-10 1:34 ` Al Viro
2012-01-10 2:02 ` Linus Torvalds
2012-01-10 10:05 ` Miklos Szeredi
2012-01-10 16:00 ` Linus Torvalds
2012-01-10 16:15 ` Al Viro
2012-01-10 16:22 ` Miklos Szeredi
2012-01-10 16:33 ` Linus Torvalds
2012-01-10 16:50 ` Miklos Szeredi
2012-01-10 18:04 ` Al Viro
2012-01-10 21:52 ` Dave Chinner
2012-01-09 21:26 ` Al Viro
2012-01-09 17:27 ` Al Viro
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