From: Andrew Morton <akpm@osdl.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: fujita.tomonori@lab.ntt.co.jp, michaelc@cs.wisc.edu,
hch@infradead.org, linux-fsdevel@vger.kernel.org,
ext2-devel@lists.sourceforge.net, open-iscsi@googlegroups.com,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: allowed pages in the block later, was Re: [Ext2-devel] [PATCH] ext3: avoid sending down non-refcounted pages
Date: Sat, 10 Dec 2005 16:47:36 -0800 [thread overview]
Message-ID: <20051210164736.6e4eaa3f.akpm@osdl.org> (raw)
In-Reply-To: <20051208134239.GA13376@infradead.org>
Christoph Hellwig <hch@infradead.org> wrote:
>
> The problem we're trying to solve here is how do implement network block
> devices (nbd, iscsi) efficiently. The zero copy codepath in the networking
> layer does need to grab additional references to pages. So to use sendpage
> we need a refcountable page. pages used by the slab allocator are not
> normally refcounted so try to do get_page/pub_page on them will break.
I don't get it. Doing get_page/put_page on a slab-allocated page should do
the right thing?
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@osdl.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: fujita.tomonori@lab.ntt.co.jp, michaelc@cs.wisc.edu,
linux-fsdevel@vger.kernel.org, ext2-devel@lists.sourceforge.net,
open-iscsi@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: allowed pages in the block later, was Re: [Ext2-devel] [PATCH] ext3: avoid sending down non-refcounted pages
Date: Sat, 10 Dec 2005 16:47:36 -0800 [thread overview]
Message-ID: <20051210164736.6e4eaa3f.akpm@osdl.org> (raw)
In-Reply-To: <20051208134239.GA13376@infradead.org>
Christoph Hellwig <hch@infradead.org> wrote:
>
> The problem we're trying to solve here is how do implement network block
> devices (nbd, iscsi) efficiently. The zero copy codepath in the networking
> layer does need to grab additional references to pages. So to use sendpage
> we need a refcountable page. pages used by the slab allocator are not
> normally refcounted so try to do get_page/pub_page on them will break.
I don't get it. Doing get_page/put_page on a slab-allocated page should do
the right thing?
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next prev parent reply other threads:[~2005-12-11 0:48 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-08 9:09 [PATCH] ext3: avoid sending down non-refcounted pages FUJITA Tomonori
2005-12-08 10:18 ` Andreas Dilger
2005-12-08 12:39 ` [Ext2-devel] " FUJITA Tomonori
2005-12-08 13:42 ` allowed pages in the block later, was " Christoph Hellwig
2005-12-08 13:42 ` Christoph Hellwig
2005-12-08 13:58 ` Pekka Enberg
2005-12-08 13:58 ` Pekka Enberg
2005-12-12 17:27 ` Christoph Hellwig
2005-12-12 17:27 ` Christoph Hellwig
2005-12-12 17:27 ` allowed pages in the block later, was " Christoph Hellwig
2005-12-08 18:18 ` allowed pages in the block later, was Re: [Ext2-devel] " Mike Christie
2005-12-08 18:18 ` Mike Christie
2005-12-08 18:22 ` Mike Christie
2005-12-08 18:22 ` Mike Christie
2005-12-08 19:20 ` Pekka Enberg
2005-12-08 19:20 ` Pekka Enberg
2005-12-11 0:47 ` Andrew Morton [this message]
2005-12-11 0:47 ` Andrew Morton
2005-12-11 8:44 ` Arjan van de Ven
2005-12-11 8:44 ` Arjan van de Ven
2005-12-11 8:44 ` allowed pages in the block later, was " Arjan van de Ven
2005-12-12 17:25 ` allowed pages in the block later, was Re: [Ext2-devel] " Christoph Hellwig
2005-12-12 17:25 ` Christoph Hellwig
2005-12-12 20:12 ` Andrew Morton
2005-12-12 20:12 ` Andrew Morton
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