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authorMel Gorman <mgorman@suse.de>2014-08-06 16:07:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-06 18:01:20 -0700
commit24b7e5819ad5cbef2b7c7376510862aa8319d240 (patch)
tree57a0f9a0216d7c0871c9cc908535f84b39fb1c85 /mm
parent2c51856c9bea9b20e4e5aab001971a5a6624db17 (diff)
downloadlinux-24b7e5819ad5cbef2b7c7376510862aa8319d240.tar.gz
mm: pagemap: avoid unnecessary overhead when tracepoints are deactivated
This was formerly the series "Improve sequential read throughput" which noted some major differences in performance of tiobench since 3.0. While there are a number of factors, two that dominated were the introduction of the fair zone allocation policy and changes to CFQ. The behaviour of fair zone allocation policy makes more sense than tiobench as a benchmark and CFQ defaults were not changed due to insufficient benchmarking. This series is what's left. It's one functional fix to the fair zone allocation policy when used on NUMA machines and a reduction of overhead in general. tiobench was used for the comparison despite its flaws as an IO benchmark as in this case we are primarily interested in the overhead of page allocator and page reclaim activity. On UMA, it makes little difference to overhead 3.16.0-rc3 3.16.0-rc3 vanilla lowercost-v5 User 383.61 386.77 System 403.83 401.74 Elapsed 5411.50 5413.11 On a 4-socket NUMA machine it's a bit more noticable 3.16.0-rc3 3.16.0-rc3 vanilla lowercost-v5 User 746.94 802.00 System 65336.22 40852.33 Elapsed 27553.52 27368.46 This patch (of 6): The LRU insertion and activate tracepoints take PFN as a parameter forcing the overhead to the caller. Move the overhead to the tracepoint fast-assign method to ensure the cost is only incurred when the tracepoint is active. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/swap.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/swap.c b/mm/swap.c
index d8eb4d09ffa2..c789d01c9ec3 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -501,7 +501,7 @@ static void __activate_page(struct page *page, struct lruvec *lruvec,
SetPageActive(page);
lru += LRU_ACTIVE;
add_page_to_lru_list(page, lruvec, lru);
- trace_mm_lru_activate(page, page_to_pfn(page));
+ trace_mm_lru_activate(page);
__count_vm_event(PGACTIVATE);
update_page_reclaim_stat(lruvec, file, 1);
@@ -988,7 +988,7 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
SetPageLRU(page);
add_page_to_lru_list(page, lruvec, lru);
update_page_reclaim_stat(lruvec, file, active);
- trace_mm_lru_insertion(page, page_to_pfn(page), lru, trace_pagemap_flags(page));
+ trace_mm_lru_insertion(page, lru);
}
/*