From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 24 Jun 2008 10:05:57 +0200 From: Jens Axboe Subject: Re: [rfc patch 4/4] splice: use do_generic_file_read() Message-ID: <20080624080557.GK20851@kernel.dk> References: <20080621154607.154640724@szeredi.hu> <20080621154727.808329488@szeredi.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080621154727.808329488@szeredi.hu> Sender: owner-linux-mm@kvack.org Return-Path: To: Miklos Szeredi Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, torvalds@linux-foundation.org List-ID: On Sat, Jun 21 2008, Miklos Szeredi wrote: > From: Miklos Szeredi > > __generic_file_splice_read() duplicates a lot of stuff common with the > generic page cache reading. So reuse that code instead to simplify > the page cache splice code. > > This also fixes some corner cases which weren't properly handled in > the splice code because of complexity issues. In particular it fixes > a problem when the filesystem (e.g. fuse) invalidates pages during the > splice operation. > > There might be some slight fall in performance due to the removal of > the gang lookup for pages. However I'm not sure if this is > significant enough to warrant the extra complication. This makes everything sync, it's a no go. Why don't we look into fixing the invalidate problem that fuse sees (can you elaborate on that?)? I tried to do a quick performance test with your patches for comparison in the cached case, but it crashes immediately in spd_release_page() -- Jens Axboe -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org