From: Christoph Lameter <clameter@sgi.com>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: Dmitry Monakhov <dmonakhov@sw.ru>,
torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
Mel Gorman <mel@skynet.ie>,
William Lee Irwin III <wli@holomorphy.com>,
David Chinner <dgc@sgi.com>, Badari Pulavarty <pbadari@gmail.com>,
Maxim Levitsky <maximlevitsky@gmail.com>,
Fengguang Wu <fengguang.wu@gmail.com>,
swin wang <wangswin@gmail.com>,
totty.lu@gmail.com, "H. Peter Anvin" <hpa@zytor.com>,
joern@lazybastard.org,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [11/36] Use page_cache_xxx in fs/buffer.c
Date: Fri, 31 Aug 2007 00:17:38 -0700 (PDT) [thread overview]
Message-ID: <Pine.LNX.4.64.0708310012370.14375@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <20070831071142.GI29452@kernel.dk>
On Fri, 31 Aug 2007, Jens Axboe wrote:
> > Could you be more specific?
>
> Size of a single segment, for instance. Or if the bio crosses a dma
> boundary. If your block is 64kb and the maximum segment size is 32kb,
> then you would need to clone the bio and split it into two.
A DMA boundary cannot be crossed AFAIK. The compound pages are aligned to
the power of two boundaries and the page allocator will not create pages
that cross the zone boundaries.
It looks like the code will correctly signal a failure if you try to write
a 64k block on a device with a maximum segment size of 32k. Isnt this
okay? One would not want to use a larger block size than supported by the
underlying hardware?
> Things like that. This isn't a problem with single page requests, as we
> based the lower possible boundaries on that.
submit_bh() is used to submit a single buffer and I think that was our
main concern here.
next prev parent reply other threads:[~2007-08-31 7:17 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20070828190551.415127746@sgi.com>
[not found] ` <20070828190735.292638294@sgi.com>
2007-08-30 0:11 ` [31/36] Large Blocksize: Core piece Mingming Cao
2007-08-30 0:12 ` Christoph Lameter
2007-08-30 0:47 ` [RFC 1/4] Large Blocksize support for Ext2/3/4 Mingming Cao
2007-08-30 0:59 ` Christoph Lameter
2007-09-01 0:01 ` Mingming Cao
2007-09-01 0:12 ` [RFC 1/2] JBD: slab management support for large block(>8k) Mingming Cao
2007-09-01 18:39 ` Christoph Hellwig
2007-09-02 11:40 ` Christoph Lameter
2007-09-02 15:28 ` Christoph Hellwig
2007-09-03 7:55 ` Christoph Lameter
2007-09-03 13:40 ` Christoph Hellwig
2007-09-03 19:31 ` Christoph Lameter
2007-09-03 19:33 ` Christoph Hellwig
2007-09-14 18:53 ` [PATCH] JBD slab cleanups Mingming Cao
2007-09-14 18:58 ` Christoph Lameter
2007-09-17 19:29 ` Mingming Cao
2007-09-17 19:34 ` Christoph Hellwig
2007-09-17 22:01 ` Badari Pulavarty
2007-09-17 22:57 ` Mingming Cao
2007-09-18 9:04 ` Christoph Hellwig
2007-09-18 16:35 ` Mingming Cao
2007-09-18 18:04 ` Dave Kleikamp
2007-09-19 1:00 ` Mingming Cao
2007-09-19 2:19 ` Andrew Morton
2007-09-19 19:15 ` Mingming Cao
2007-09-19 19:22 ` [PATCH] JBD: use GFP_NOFS in kmalloc Mingming Cao
2007-09-19 21:34 ` Andrew Morton
2007-09-19 21:55 ` Mingming Cao
2007-09-20 4:25 ` Andreas Dilger
2007-09-19 19:26 ` [PATCH] JBD slab cleanups Dave Kleikamp
2007-09-19 19:28 ` Dave Kleikamp
2007-09-19 20:47 ` Mingming Cao
2007-09-19 19:48 ` Andreas Dilger
2007-09-19 22:03 ` Mingming Cao
2007-09-01 0:12 ` [RFC 2/2] JBD: blocks reservation fix for large block support Mingming Cao
2007-08-30 0:47 ` [RFC 2/4]ext2: fix rec_len overflow with 64KB block size Mingming Cao
[not found] ` <20070828190730.220393749@sgi.com>
2007-08-30 9:20 ` [11/36] Use page_cache_xxx in fs/buffer.c Dmitry Monakhov
2007-08-30 18:14 ` Christoph Lameter
2007-08-31 1:47 ` Christoph Lameter
2007-08-31 6:56 ` Jens Axboe
2007-08-31 7:03 ` Christoph Lameter
2007-08-31 7:11 ` Jens Axboe
2007-08-31 7:17 ` Christoph Lameter [this message]
2007-08-31 7:26 ` Jens Axboe
2007-08-31 7:33 ` Christoph Lameter
2007-08-31 7:43 ` Jens Axboe
2007-08-31 7:52 ` Christoph Lameter
2007-08-31 8:12 ` Jens Axboe
2007-08-31 15:22 ` Christoph Lameter
2007-08-31 16:35 ` Jörn Engel
2007-08-31 19:00 ` Jens Axboe
2007-08-31 8:36 ` Dmitry Monakhov
2007-08-31 15:28 ` Christoph Lameter
[not found] ` <20070828192034.GA13883@lst.de>
[not found] ` <Pine.LNX.4.64.0708281254070.16473@schroedinger.engr.sgi.com>
2007-09-01 1:11 ` [00/36] Large Blocksize Support V6 Christoph Lameter
2007-09-01 19:17 ` Peter Zijlstra
2007-09-02 11:44 ` Christoph Lameter
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