From c8b36003121834cb77fcaf8a1ce0a454d7a97891 Mon Sep 17 00:00:00 2001 From: Richard Chang Date: Wed, 28 Feb 2024 05:11:17 +0000 Subject: mm: add alloc_contig_migrate_range allocation statistics alloc_contig_migrate_range has every information to be able to understand big contiguous allocation latency. For example, how many pages are migrated, how many times they were needed to unmap from page tables. This patch adds the trace event to collect the allocation statistics. In the field, it was quite useful to understand CMA allocation latency. [akpm@linux-foundation.org: a/trace_mm_alloc_config_migrate_range_info_enabled/trace_mm_alloc_contig_migrate_range_info_enabled] Link: https://lkml.kernel.org/r/20240228051127.2859472-1-richardycc@google.com Signed-off-by: Richard Chang Reviewed-by: Steven Rostedt (Google) Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Minchan Kim Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton --- mm/page_alloc.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7873e9375802..29c982542dcc 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6222,9 +6222,14 @@ static void alloc_contig_dump_pages(struct list_head *page_list) } } -/* [start, end) must belong to a single zone. */ +/* + * [start, end) must belong to a single zone. + * @migratetype: using migratetype to filter the type of migration in + * trace_mm_alloc_contig_migrate_range_info. + */ int __alloc_contig_migrate_range(struct compact_control *cc, - unsigned long start, unsigned long end) + unsigned long start, unsigned long end, + int migratetype) { /* This function is based on compact_zone() from compaction.c. */ unsigned int nr_reclaimed; @@ -6235,6 +6240,10 @@ int __alloc_contig_migrate_range(struct compact_control *cc, .nid = zone_to_nid(cc->zone), .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, }; + struct page *page; + unsigned long total_mapped = 0; + unsigned long total_migrated = 0; + unsigned long total_reclaimed = 0; lru_cache_disable(); @@ -6260,9 +6269,18 @@ int __alloc_contig_migrate_range(struct compact_control *cc, &cc->migratepages); cc->nr_migratepages -= nr_reclaimed; + if (trace_mm_alloc_contig_migrate_range_info_enabled()) { + total_reclaimed += nr_reclaimed; + list_for_each_entry(page, &cc->migratepages, lru) + total_mapped += page_mapcount(page); + } + ret = migrate_pages(&cc->migratepages, alloc_migration_target, NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE, NULL); + if (trace_mm_alloc_contig_migrate_range_info_enabled() && !ret) + total_migrated += cc->nr_migratepages; + /* * On -ENOMEM, migrate_pages() bails out right away. It is pointless * to retry again over this error, so do the same here. @@ -6276,9 +6294,13 @@ int __alloc_contig_migrate_range(struct compact_control *cc, if (!(cc->gfp_mask & __GFP_NOWARN) && ret == -EBUSY) alloc_contig_dump_pages(&cc->migratepages); putback_movable_pages(&cc->migratepages); - return ret; } - return 0; + + trace_mm_alloc_contig_migrate_range_info(start, end, migratetype, + total_migrated, + total_reclaimed, + total_mapped); + return (ret < 0) ? ret : 0; } /** @@ -6358,7 +6380,7 @@ int alloc_contig_range(unsigned long start, unsigned long end, * allocated. So, if we fall through be sure to clear ret so that * -EBUSY is not accidentally used or returned to caller. */ - ret = __alloc_contig_migrate_range(&cc, start, end); + ret = __alloc_contig_migrate_range(&cc, start, end, migratetype); if (ret && ret != -EBUSY) goto done; ret = 0; -- cgit v1.2.3