24b7e5819a
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>
88 lines
2.1 KiB
C
88 lines
2.1 KiB
C
#undef TRACE_SYSTEM
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#define TRACE_SYSTEM pagemap
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#if !defined(_TRACE_PAGEMAP_H) || defined(TRACE_HEADER_MULTI_READ)
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#define _TRACE_PAGEMAP_H
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#include <linux/tracepoint.h>
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#include <linux/mm.h>
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#define PAGEMAP_MAPPED 0x0001u
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#define PAGEMAP_ANONYMOUS 0x0002u
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#define PAGEMAP_FILE 0x0004u
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#define PAGEMAP_SWAPCACHE 0x0008u
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#define PAGEMAP_SWAPBACKED 0x0010u
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#define PAGEMAP_MAPPEDDISK 0x0020u
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#define PAGEMAP_BUFFERS 0x0040u
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#define trace_pagemap_flags(page) ( \
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(PageAnon(page) ? PAGEMAP_ANONYMOUS : PAGEMAP_FILE) | \
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(page_mapped(page) ? PAGEMAP_MAPPED : 0) | \
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(PageSwapCache(page) ? PAGEMAP_SWAPCACHE : 0) | \
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(PageSwapBacked(page) ? PAGEMAP_SWAPBACKED : 0) | \
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(PageMappedToDisk(page) ? PAGEMAP_MAPPEDDISK : 0) | \
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(page_has_private(page) ? PAGEMAP_BUFFERS : 0) \
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)
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TRACE_EVENT(mm_lru_insertion,
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TP_PROTO(
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struct page *page,
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int lru
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),
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TP_ARGS(page, lru),
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TP_STRUCT__entry(
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__field(struct page *, page )
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__field(unsigned long, pfn )
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__field(int, lru )
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__field(unsigned long, flags )
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),
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TP_fast_assign(
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__entry->page = page;
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__entry->pfn = page_to_pfn(page);
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__entry->lru = lru;
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__entry->flags = trace_pagemap_flags(page);
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),
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/* Flag format is based on page-types.c formatting for pagemap */
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TP_printk("page=%p pfn=%lu lru=%d flags=%s%s%s%s%s%s",
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__entry->page,
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__entry->pfn,
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__entry->lru,
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__entry->flags & PAGEMAP_MAPPED ? "M" : " ",
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__entry->flags & PAGEMAP_ANONYMOUS ? "a" : "f",
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__entry->flags & PAGEMAP_SWAPCACHE ? "s" : " ",
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__entry->flags & PAGEMAP_SWAPBACKED ? "b" : " ",
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__entry->flags & PAGEMAP_MAPPEDDISK ? "d" : " ",
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__entry->flags & PAGEMAP_BUFFERS ? "B" : " ")
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);
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TRACE_EVENT(mm_lru_activate,
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TP_PROTO(struct page *page),
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TP_ARGS(page),
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TP_STRUCT__entry(
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__field(struct page *, page )
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__field(unsigned long, pfn )
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),
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TP_fast_assign(
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__entry->page = page;
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__entry->pfn = page_to_pfn(page);
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),
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/* Flag format is based on page-types.c formatting for pagemap */
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TP_printk("page=%p pfn=%lu", __entry->page, __entry->pfn)
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);
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#endif /* _TRACE_PAGEMAP_H */
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/* This part must be outside protection */
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#include <trace/define_trace.h>
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