The patch titled
Subject: mm: pagemap: avoid unnecessary overhead when tracepoints are deactivated
has been added to the -mm tree. Its filename is
mm-pagemap-avoid-unnecessary-overhead-when-tracepoints-are-deactivated.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-pagemap-avoid-unnecessary-overhead-when-tracepoints-are-deactivated.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-pagemap-avoid-unnecessary-overhead-when-tracepoints-are-deactivated.patch
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------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxx>
Subject: mm: pagemap: avoid unnecessary overhead when tracepoints are deactivated
IO performance since 3.0 has been a mixed bag. In many respects we are
better and in some we are worse and one of those places is sequential read
throughput. This is visible in a number of benchmarks but I looked at
tiobench the closest. This is using ext3 on a mid-range desktop and the
series applied.
3.16.0-rc2 3.0.0 3.16.0-rc2
vanilla vanilla fairzone-v4r5
Min SeqRead-MB/sec-1 120.92 ( 0.00%) 133.65 ( 10.53%) 140.68 ( 16.34%)
Min SeqRead-MB/sec-2 100.25 ( 0.00%) 121.74 ( 21.44%) 118.13 ( 17.84%)
Min SeqRead-MB/sec-4 96.27 ( 0.00%) 113.48 ( 17.88%) 109.84 ( 14.10%)
Min SeqRead-MB/sec-8 83.55 ( 0.00%) 97.87 ( 17.14%) 89.62 ( 7.27%)
Min SeqRead-MB/sec-16 66.77 ( 0.00%) 82.59 ( 23.69%) 70.49 ( 5.57%)
Overall system CPU usage is reduced
3.16.0-rc2 3.0.0 3.16.0-rc2
vanilla vanilla fairzone-v4
User 390.13 251.45 396.13
System 404.41 295.13 389.61
Elapsed 5412.45 5072.42 5163.49
This series does not fully restore throughput performance to 3.0 levels
but it brings it close for lower thread counts. Higher thread counts are
known to be worse than 3.0 due to CFQ changes but there is no appetite for
changing the defaults there.
This patch (of 4):
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@xxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/trace/events/pagemap.h | 16 +++++++---------
mm/swap.c | 4 ++--
2 files changed, 9 insertions(+), 11 deletions(-)
diff -puN include/trace/events/pagemap.h~mm-pagemap-avoid-unnecessary-overhead-when-tracepoints-are-deactivated include/trace/events/pagemap.h
--- a/include/trace/events/pagemap.h~mm-pagemap-avoid-unnecessary-overhead-when-tracepoints-are-deactivated
+++ a/include/trace/events/pagemap.h
@@ -28,12 +28,10 @@ TRACE_EVENT(mm_lru_insertion,
TP_PROTO(
struct page *page,
- unsigned long pfn,
- int lru,
- unsigned long flags
+ int lru
),
- TP_ARGS(page, pfn, lru, flags),
+ TP_ARGS(page, lru),
TP_STRUCT__entry(
__field(struct page *, page )
@@ -44,9 +42,9 @@ TRACE_EVENT(mm_lru_insertion,
TP_fast_assign(
__entry->page = page;
- __entry->pfn = pfn;
+ __entry->pfn = page_to_pfn(page);
__entry->lru = lru;
- __entry->flags = flags;
+ __entry->flags = trace_pagemap_flags(page);
),
/* Flag format is based on page-types.c formatting for pagemap */
@@ -64,9 +62,9 @@ TRACE_EVENT(mm_lru_insertion,
TRACE_EVENT(mm_lru_activate,
- TP_PROTO(struct page *page, unsigned long pfn),
+ TP_PROTO(struct page *page),
- TP_ARGS(page, pfn),
+ TP_ARGS(page),
TP_STRUCT__entry(
__field(struct page *, page )
@@ -75,7 +73,7 @@ TRACE_EVENT(mm_lru_activate,
TP_fast_assign(
__entry->page = page;
- __entry->pfn = pfn;
+ __entry->pfn = page_to_pfn(page);
),
/* Flag format is based on page-types.c formatting for pagemap */
diff -puN mm/swap.c~mm-pagemap-avoid-unnecessary-overhead-when-tracepoints-are-deactivated mm/swap.c
--- a/mm/swap.c~mm-pagemap-avoid-unnecessary-overhead-when-tracepoints-are-deactivated
+++ a/mm/swap.c
@@ -502,7 +502,7 @@ static void __activate_page(struct page
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);
@@ -1036,7 +1036,7 @@ static void __pagevec_lru_add_fn(struct
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);
}
/*
_
Patches currently in -mm which might be from mgorman@xxxxxxx are
mm-page_alloc-fix-cma-area-initialisation-when-pageblock-max_order.patch
mm-page_alloc-add-__meminit-to-alloc_pages_exact_nid.patch
mm-thp-move-invariant-bug-check-out-of-loop-in-__split_huge_page_map.patch
mm-thp-replace-smp_mb-after-atomic_add-by-smp_mb__after_atomic.patch
mem-hotplug-improve-zone_movable_is_highmem-logic.patch
mm-vmscan-remove-remains-of-kswapd-managed-zone-all_unreclaimable.patch
mm-vmscan-rework-compaction-ready-signaling-in-direct-reclaim.patch
mm-vmscan-remove-all_unreclaimable.patch
mm-vmscan-move-swappiness-out-of-scan_control.patch
tracing-tell-mm_migrate_pages-event-about-numa_misplaced.patch
mm-export-nr_shmem-via-sysinfo2-si_meminfo-interfaces.patch
mm-pagemap-avoid-unnecessary-overhead-when-tracepoints-are-deactivated.patch
mm-rearrange-zone-fields-into-read-only-page-alloc-statistics-and-page-reclaim-lines.patch
mm-vmscan-do-not-reclaim-from-lower-zones-if-they-are-balanced.patch
mm-page_alloc-reduce-cost-of-the-fair-zone-allocation-policy.patch
mm-introduce-do_shared_fault-and-drop-do_fault-fix-fix.patch
mm-compactionc-isolate_freepages_block-small-tuneup.patch
mm-zbud-zbud_alloc-minor-param-change.patch
mm-zbud-change-zbud_alloc-size-type-to-size_t.patch
mm-zpool-implement-common-zpool-api-to-zbud-zsmalloc.patch
mm-zpool-zbud-zsmalloc-implement-zpool.patch
mm-zpool-update-zswap-to-use-zpool.patch
mm-zpool-prevent-zbud-zsmalloc-from-unloading-when-used.patch
do_shared_fault-check-that-mmap_sem-is-held.patch
linux-next.patch
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