tree a04b9925616414ce8eb228d0ea9271d31840a1c4
parent b2dfc26ff6837af8e334bb9c6f769cb6e0f6a86c
author Lee Susman <lsusman@codeaurora.org> 1367764277 +0300
committer Lee Susman <lsusman@codeaurora.org> 1371995002 +0300

mm: pass readahead info down to the i/o scheduler

Some i/o schedulers (i.e. row-iosched, cfq-iosched) deploy an idling
algorithm in order to be better synced with the readahead algorithm.
Idling is a prediction algorithm for incoming read requests.

In this patch we mark pages which are part of a readahead window, by
setting a newly introduced flag. With this flag, the i/o scheduler can
identify a request which is associated with a readahead page. This
enables the i/o scheduler's idling mechanism to be en-sync with the
readahead mechanism and, in turn, can increase read throughput.

Change-Id: I0654f23315b6d19d71bcc9cc029c6b281a44b196
Signed-off-by: Lee Susman <lsusman@codeaurora.org>