From: Fengguang Wu <wfg@mail.ustc.edu.cn>
Date: Thu, 19 Jul 2007 08:48:05 +0000 (-0700)
Subject: readahead: move synchronous readahead call out of splice loop
X-Git-Tag: v2.6.23-rc1~429
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=431a4820bfcdf7ff530e745230bafb06c9bf2d6d;p=pandora-kernel.git

readahead: move synchronous readahead call out of splice loop

Move synchronous page_cache_readahead_ondemand() call out of splice loop.

This avoids one pointless page allocation/insertion in case of non-zero
ra_pages, or many pointless readahead calls in case of zero ra_pages.

Note that if a user sets ra_pages to less than PIPE_BUFFERS=16 pages, he will
not get expected readahead behavior anyway.  The splice code works in batches
of 16 pages, which can be taken as another form of synchronous readahead.

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

Reading git-diff-tree failed