From: Christoph Hellwig <hch@infradead.org>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>,
dsterba@suse.cz, Christophe Leroy <christophe.leroy@c-s.fr>,
erhard_f@mailbox.org, Chris Mason <clm@fb.com>,
Josef Bacik <josef@toxicpanda.com>,
David Sterba <dsterba@suse.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-btrfs@vger.kernel.org, linux-mm@kvack.org,
stable@vger.kernel.org, Dave Chinner <david@fromorbit.com>
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
WARNING: multiple messages have this Message-ID (diff)
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
next prev parent reply other threads:[~2019-08-21 1:49 UTC|newest]
Thread overview: 10+ 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 7:44 ` Christophe Leroy
2019-08-17 18:11 ` Sasha Levin
2019-08-19 17:46 ` David Sterba
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]
2019-08-21 1:48 ` Christoph Hellwig
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=20190821014858.GA9158@infradead.org \
--to=hch@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=christophe.leroy@c-s.fr \
--cc=clm@fb.com \
--cc=david@fromorbit.com \
--cc=dsterba@suse.com \
--cc=dsterba@suse.cz \
--cc=erhard_f@mailbox.org \
--cc=josef@toxicpanda.com \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=stable@vger.kernel.org \
--cc=vbabka@suse.cz \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.