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| author | Lee Susman <lsusman@codeaurora.org> | 2013-06-27 16:09:42 -0500 |
|---|---|---|
| committer | Ziyan <jaraidaniel@gmail.com> | 2016-01-08 10:43:02 +0100 |
| commit | 37527390652db2937cda6206f28e11ef34d92ada (patch) | |
| tree | 0016122e0cf676e117be7f3f7794918578f6b76f /mm | |
| parent | aea0d63eed9227a15fcc48aa55da7f7027cf7f79 (diff) | |
| download | kernel_samsung_tuna-37527390652db2937cda6206f28e11ef34d92ada.tar.gz kernel_samsung_tuna-37527390652db2937cda6206f28e11ef34d92ada.tar.bz2 kernel_samsung_tuna-37527390652db2937cda6206f28e11ef34d92ada.zip | |
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>
Signed-off-by: Paul Reioux <reioux@gmail.com>
Conflicts:
include/linux/page-flags.h
Conflicts:
include/linux/page-flags.h
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 1 | ||||
| -rw-r--r-- | mm/readahead.c | 3 |
2 files changed, 4 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 470993a14e5..4410edd4e33 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5846,6 +5846,7 @@ static struct trace_print_flags pageflag_names[] = { #ifdef CONFIG_MEMORY_FAILURE {1UL << PG_hwpoison, "hwpoison" }, #endif + {1UL << PG_readahead, "PG_readahead" }, {-1UL, NULL }, }; diff --git a/mm/readahead.c b/mm/readahead.c index df60df9e32c..4df6dc77df0 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -210,6 +210,9 @@ __do_page_cache_readahead(struct address_space *mapping, struct file *filp, if (!page) break; page->index = page_offset; + + page->flags |= (1L << PG_readahead); + list_add(&page->lru, &page_pool); if (page_idx == nr_to_read - lookahead_size) SetPageReadahead(page); |