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
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@xxxxxxx>
Acked-by: 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);
@@ -1024,7 +1024,7 @@ 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-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-replace-init_page_accessed-by-__setpagereferenced.patch
mm-update-the-description-for-vm_total_pages.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-move-zone-pages_scanned-into-a-vmstat-counter.patch
mm-vmscan-only-update-per-cpu-thresholds-for-online-cpu.patch
mm-page_alloc-abort-fair-zone-allocation-policy-when-remotes-nodes-are-encountered.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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