f8c9301fa5
During compaction, update_nr_listpages() has been used to count remaining non-migrated and free pages after a call to migrage_pages(). The freepages counting has become unneccessary, and it turns out that migratepages counting is also unnecessary in most cases. The only situation when it's needed to count cc->migratepages is when migrate_pages() returns with a negative error code. Otherwise, the non-negative return value is the number of pages that were not migrated, which is exactly the count of remaining pages in the cc->migratepages list. Furthermore, any non-zero count is only interesting for the tracepoint of mm_compaction_migratepages events, because after that all remaining unmigrated pages are put back and their count is set to 0. This patch therefore removes update_nr_listpages() completely, and changes the tracepoint definition so that the manual counting is done only when the tracepoint is enabled, and only when migrate_pages() returns a negative error code. Furthermore, migrate_pages() and the tracepoints won't be called when there's nothing to migrate. This potentially avoids some wasted cycles and reduces the volume of uninteresting mm_compaction_migratepages events where "nr_migrated=0 nr_failed=0". In the stress-highalloc mmtest, this was about 75% of the events. The mm_compaction_isolate_migratepages event is better for determining that nothing was isolated for migration, and this one was just duplicating the info. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
133 lines
2.9 KiB
C
133 lines
2.9 KiB
C
#undef TRACE_SYSTEM
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#define TRACE_SYSTEM compaction
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#if !defined(_TRACE_COMPACTION_H) || defined(TRACE_HEADER_MULTI_READ)
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#define _TRACE_COMPACTION_H
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#include <linux/types.h>
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#include <linux/list.h>
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#include <linux/tracepoint.h>
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#include <trace/events/gfpflags.h>
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DECLARE_EVENT_CLASS(mm_compaction_isolate_template,
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TP_PROTO(unsigned long nr_scanned,
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unsigned long nr_taken),
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TP_ARGS(nr_scanned, nr_taken),
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TP_STRUCT__entry(
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__field(unsigned long, nr_scanned)
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__field(unsigned long, nr_taken)
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),
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TP_fast_assign(
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__entry->nr_scanned = nr_scanned;
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__entry->nr_taken = nr_taken;
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),
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TP_printk("nr_scanned=%lu nr_taken=%lu",
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__entry->nr_scanned,
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__entry->nr_taken)
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);
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DEFINE_EVENT(mm_compaction_isolate_template, mm_compaction_isolate_migratepages,
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TP_PROTO(unsigned long nr_scanned,
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unsigned long nr_taken),
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TP_ARGS(nr_scanned, nr_taken)
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);
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DEFINE_EVENT(mm_compaction_isolate_template, mm_compaction_isolate_freepages,
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TP_PROTO(unsigned long nr_scanned,
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unsigned long nr_taken),
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TP_ARGS(nr_scanned, nr_taken)
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);
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TRACE_EVENT(mm_compaction_migratepages,
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TP_PROTO(unsigned long nr_all,
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int migrate_rc,
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struct list_head *migratepages),
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TP_ARGS(nr_all, migrate_rc, migratepages),
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TP_STRUCT__entry(
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__field(unsigned long, nr_migrated)
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__field(unsigned long, nr_failed)
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),
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TP_fast_assign(
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unsigned long nr_failed = 0;
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struct list_head *page_lru;
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/*
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* migrate_pages() returns either a non-negative number
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* with the number of pages that failed migration, or an
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* error code, in which case we need to count the remaining
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* pages manually
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*/
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if (migrate_rc >= 0)
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nr_failed = migrate_rc;
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else
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list_for_each(page_lru, migratepages)
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nr_failed++;
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__entry->nr_migrated = nr_all - nr_failed;
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__entry->nr_failed = nr_failed;
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),
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TP_printk("nr_migrated=%lu nr_failed=%lu",
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__entry->nr_migrated,
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__entry->nr_failed)
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);
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TRACE_EVENT(mm_compaction_begin,
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TP_PROTO(unsigned long zone_start, unsigned long migrate_start,
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unsigned long free_start, unsigned long zone_end),
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TP_ARGS(zone_start, migrate_start, free_start, zone_end),
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TP_STRUCT__entry(
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__field(unsigned long, zone_start)
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__field(unsigned long, migrate_start)
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__field(unsigned long, free_start)
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__field(unsigned long, zone_end)
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),
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TP_fast_assign(
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__entry->zone_start = zone_start;
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__entry->migrate_start = migrate_start;
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__entry->free_start = free_start;
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__entry->zone_end = zone_end;
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),
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TP_printk("zone_start=%lu migrate_start=%lu free_start=%lu zone_end=%lu",
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__entry->zone_start,
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__entry->migrate_start,
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__entry->free_start,
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__entry->zone_end)
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);
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TRACE_EVENT(mm_compaction_end,
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TP_PROTO(int status),
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TP_ARGS(status),
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TP_STRUCT__entry(
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__field(int, status)
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),
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TP_fast_assign(
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__entry->status = status;
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),
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TP_printk("status=%d", __entry->status)
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);
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#endif /* _TRACE_COMPACTION_H */
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/* This part must be outside protection */
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#include <trace/define_trace.h>
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