tree ac73cf0c8325783a28c4d16c783f6fd96d17be7c
parent 6b10c6c9fbfe754e8482efb8c8b84f8e40c0f2eb
author Fengguang Wu <wfg@mail.ustc.edu.cn> 1192523075 -0700
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1192552972 -0700

readahead: remove the local copy of ra in do_generic_mapping_read()

The local copy of ra in do_generic_mapping_read() can now go away.

It predates readanead(req_size).  In a time when the readahead code was called
on *every* single page.  Hence a local has to be made to reduce the chance of
the readahead state being overwritten by a concurrent reader.  More details
in: Linux: Random File I/O Regressions In 2.6
<http://kerneltrap.org/node/3039>

Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
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>