From: Christoph Hellwig <hch@infradead.org>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: erhard_f@mailbox.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, Dave Chinner <david@fromorbit.com>,
Josef Bacik <josef@toxicpanda.com>,
stable@vger.kernel.org, dsterba@suse.cz,
Christoph Hellwig <hch@infradead.org>, Chris Mason <clm@fb.com>,
David Sterba <dsterba@suse.com>,
Andrew Morton <akpm@linux-foundation.org>,
linuxppc-dev@lists.ozlabs.org, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] btrfs: fix allocation of bitmap pages.
Date: Tue, 20 Aug 2019 18:48:58 -0700 [thread overview]
Message-ID: <20190821014858.GA9158@infradead.org> (raw)
In-Reply-To: <6f99b73c-db8f-8135-b827-0a135734d7da@suse.cz>
On Tue, Aug 20, 2019 at 01:06:25PM +0200, Vlastimil Babka wrote:
> > The whole point of copy_page is to copy exactly one page and it makes
> > sense to assume that is aligned. A sane memcpy would use the same
> > underlying primitives as well after checking they fit. So I think the
> > prime issue here is btrfs' use of copy_page instead of memcpy. The
> > secondary issue is slub fucking up alignments for no good reason. We
> > just got bitten by that crap again in XFS as well :(
>
> Meh, I should finally get back to https://lwn.net/Articles/787740/ right
Yes. For now Dave came up with an idea for a workaround that will
be forward-compatible with that:
https://www.spinics.net/lists/linux-xfs/msg30521.html
prev parent reply other threads:[~2019-08-21 1:51 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-17 7:44 [PATCH] btrfs: fix allocation of bitmap pages Christophe Leroy
2019-08-17 18:11 ` Sasha Levin
2019-08-19 17:46 ` David Sterba
2019-08-19 20:32 ` Christophe Leroy
2019-08-20 2:30 ` Christoph Hellwig
2019-08-20 11:06 ` Vlastimil Babka
2019-08-21 1:48 ` Christoph Hellwig [this message]
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