From: James Bottomley <James.Bottomley@SteelEye.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
linux-scsi@vger.kernel.org,
Linux Kernel Development <linux-kernel@vger.kernel.org>,
Alessandro Rubini <rubini@vision.unipv.it>,
Linux/PPC Development <linuxppc-dev@ozlabs.org>,
Paul Mackerras <paulus@samba.org>,
Jens Axboe <jens.axboe@oracle.com>,
Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Subject: Re: [patch 5/6] ps3: BD/DVD/CD-ROM Storage Driver
Date: Mon, 16 Jul 2007 17:03:34 -0500 [thread overview]
Message-ID: <1184623415.3447.48.camel@localhost.localdomain> (raw)
In-Reply-To: <1184622555.25235.91.camel@localhost.localdomain>
On Tue, 2007-07-17 at 07:49 +1000, Benjamin Herrenschmidt wrote:
> > No ... that was the point of flush_kernel_dcache_page(). The page in
> > question is page cache backed and contains user mappings. However, the
> > block layer has already done a flush_dcache_page() in get_user_pages()
> > and the user shouldn't be touching memory under I/O (unless they want
> > self induced aliasing problems) so we're free to assume all the user
> > cachelines are purged, hence all we have to do is flush the kernel alias
> > to bring the page up to date and make the users see it correctly.
>
> The block layer will have done that even in the swap-out path ? (Just
> asking... I'm not very familiar with the block layer)
Er ... not really, this is the I/O path for user initiated I/O. The
page out path, by definition, can't have any extant user mappings. For
page out, the relevant page is flushed before its mapping is detached,
and then it can be paged to the backing store (or for anonymous pages to
the swap device) when no mappings remain.
James
next prev parent reply other threads:[~2007-07-16 22:03 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-04 13:22 [patch 0/6] PS3 Storage Drivers for 2.6.23, take 4 Geert Uytterhoeven
2007-07-04 13:22 ` [patch 1/6] ps3: Preallocate bootmem memory for the PS3 FLASH ROM storage driver Geert Uytterhoeven
2007-07-04 13:22 ` [patch 2/6] ps3: Storage Driver Core Geert Uytterhoeven
2007-07-04 13:22 ` [patch 3/6] ps3: Storage device registration routines Geert Uytterhoeven
2007-07-04 13:22 ` [patch 4/6] ps3: Disk Storage Driver Geert Uytterhoeven
2007-07-04 13:22 ` [patch 5/6] ps3: BD/DVD/CD-ROM " Geert Uytterhoeven
2007-07-13 13:02 ` James Bottomley
2007-07-13 13:05 ` Jens Axboe
2007-07-13 13:25 ` Geert Uytterhoeven
2007-07-13 13:34 ` James Bottomley
2007-07-13 13:45 ` Geert Uytterhoeven
2007-07-13 14:02 ` James Bottomley
2007-07-13 14:19 ` Arnd Bergmann
2007-07-13 15:10 ` Geert Uytterhoeven
2007-07-13 15:28 ` James Bottomley
2007-07-13 20:13 ` Geert Uytterhoeven
2007-07-16 11:43 ` Geert Uytterhoeven
2007-07-16 12:16 ` Jens Axboe
2007-07-16 12:59 ` Geert Uytterhoeven
2007-07-16 13:04 ` Jens Axboe
2007-07-16 13:24 ` Geert Uytterhoeven
2007-07-16 13:33 ` Jens Axboe
2007-07-16 21:38 ` Benjamin Herrenschmidt
2007-07-16 13:47 ` James Bottomley
2007-07-16 14:38 ` Jens Axboe
2007-07-16 14:59 ` Geert Uytterhoeven
2007-07-16 21:40 ` Benjamin Herrenschmidt
2007-07-16 21:49 ` Benjamin Herrenschmidt
2007-07-16 22:03 ` James Bottomley [this message]
2007-07-16 22:12 ` Benjamin Herrenschmidt
2007-07-13 16:35 ` Jens Axboe
2007-07-13 23:12 ` Benjamin Herrenschmidt
2007-07-16 12:08 ` Segher Boessenkool
2007-07-13 14:51 ` Jens Axboe
2007-07-13 23:06 ` Benjamin Herrenschmidt
2007-07-04 13:22 ` [patch 6/6] ps3: FLASH ROM " Geert Uytterhoeven
2007-07-10 7:45 ` [patch 0/6] PS3 Storage Drivers for 2.6.23, take 4 Geert Uytterhoeven
2007-07-10 7:55 ` Jens Axboe
2007-07-10 8:01 ` Paul Mackerras
2007-07-10 8:32 ` Jens Axboe
2007-07-13 9:31 ` Geert Uytterhoeven
2007-07-13 12:27 ` PS3 Storage Driver O_DIRECT issue Olaf Hering
2007-07-13 13:34 ` Geert Uytterhoeven
2007-07-17 16:40 ` Geoff Levand
2007-07-18 16:12 ` Geert Uytterhoeven
2007-07-18 17:57 ` Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2007-06-21 14:14 [patch 0/6] PS3 Storage Drivers for 2.6.23, take 3 Geert Uytterhoeven
2007-06-21 14:14 ` [patch 5/6] ps3: BD/DVD/CD-ROM Storage Driver Geert Uytterhoeven
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=1184623415.3447.48.camel@localhost.localdomain \
--to=james.bottomley@steeleye.com \
--cc=Geert.Uytterhoeven@sonycom.com \
--cc=arnd@arndb.de \
--cc=benh@kernel.crashing.org \
--cc=jens.axboe@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=linuxppc-dev@ozlabs.org \
--cc=paulus@samba.org \
--cc=rubini@vision.unipv.it \
/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).