From: Mel Gorman <mgorman@techsingularity.net> To: Andrew Morton <akpm@linux-foundation.org>, Linux-MM <linux-mm@kvack.org> Cc: Johannes Weiner <hannes@cmpxchg.org>, Minchan Kim <minchan@kernel.org>, LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mgorman@techsingularity.net> Subject: [PATCH 3/4] mm, page_alloc: fix dirtyable highmem calculation Date: Wed, 13 Jul 2016 11:00:03 +0100 [thread overview] Message-ID: <1468404004-5085-4-git-send-email-mgorman@techsingularity.net> (raw) In-Reply-To: <1468404004-5085-1-git-send-email-mgorman@techsingularity.net> From: Minchan Kim <minchan@kernel.org> Note from Mel: This may optionally be considered a fix to the mmotm patch mm-page_alloc-consider-dirtyable-memory-in-terms-of-nodes.patch but if so, please preserve credit for Minchan. When I tested vmscale in mmtest in 32bit, I found the benchmark was slow down 0.5 times. base node 1 global-1 User 12.98 16.04 System 147.61 166.42 Elapsed 26.48 38.08 With vmstat, I found IO wait avg is much increased compared to base. The reason was highmem_dirtyable_memory accumulates free pages and highmem_file_pages from HIGHMEM to MOVABLE zones which was wrong. With that, dirth_thresh in throtlle_vm_write is always 0 so that it calls congestion_wait frequently if writeback starts. With this patch, it is much recovered. base node fi 1 global-1 fix User 12.98 16.04 13.78 System 147.61 166.42 143.92 Elapsed 26.48 38.08 29.64 Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> --- mm/page-writeback.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0bca2376bd42..7b41d1290783 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -307,27 +307,31 @@ static unsigned long highmem_dirtyable_memory(unsigned long total) { #ifdef CONFIG_HIGHMEM int node; - unsigned long x = 0; + unsigned long x; int i; - unsigned long dirtyable = atomic_read(&highmem_file_pages); + unsigned long dirtyable = 0; for_each_node_state(node, N_HIGH_MEMORY) { for (i = ZONE_NORMAL + 1; i < MAX_NR_ZONES; i++) { struct zone *z; + unsigned long nr_pages; if (!is_highmem_idx(i)) continue; z = &NODE_DATA(node)->node_zones[i]; - dirtyable += zone_page_state(z, NR_FREE_PAGES); + if (!populated_zone(z)) + continue; + nr_pages = zone_page_state(z, NR_FREE_PAGES); /* watch for underflows */ - dirtyable -= min(dirtyable, high_wmark_pages(z)); - - x += dirtyable; + nr_pages -= min(nr_pages, high_wmark_pages(z)); + dirtyable += nr_pages; } } + x = dirtyable + atomic_read(&highmem_file_pages); + /* * Unreclaimable memory (kernel memory or anonymous memory * without swap) can bring down the dirtyable pages below -- 2.6.4
WARNING: multiple messages have this Message-ID (diff)
From: Mel Gorman <mgorman@techsingularity.net> To: Andrew Morton <akpm@linux-foundation.org>, Linux-MM <linux-mm@kvack.org> Cc: Johannes Weiner <hannes@cmpxchg.org>, Minchan Kim <minchan@kernel.org>, LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mgorman@techsingularity.net> Subject: [PATCH 3/4] mm, page_alloc: fix dirtyable highmem calculation Date: Wed, 13 Jul 2016 11:00:03 +0100 [thread overview] Message-ID: <1468404004-5085-4-git-send-email-mgorman@techsingularity.net> (raw) In-Reply-To: <1468404004-5085-1-git-send-email-mgorman@techsingularity.net> From: Minchan Kim <minchan@kernel.org> Note from Mel: This may optionally be considered a fix to the mmotm patch mm-page_alloc-consider-dirtyable-memory-in-terms-of-nodes.patch but if so, please preserve credit for Minchan. When I tested vmscale in mmtest in 32bit, I found the benchmark was slow down 0.5 times. base node 1 global-1 User 12.98 16.04 System 147.61 166.42 Elapsed 26.48 38.08 With vmstat, I found IO wait avg is much increased compared to base. The reason was highmem_dirtyable_memory accumulates free pages and highmem_file_pages from HIGHMEM to MOVABLE zones which was wrong. With that, dirth_thresh in throtlle_vm_write is always 0 so that it calls congestion_wait frequently if writeback starts. With this patch, it is much recovered. base node fi 1 global-1 fix User 12.98 16.04 13.78 System 147.61 166.42 143.92 Elapsed 26.48 38.08 29.64 Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> --- mm/page-writeback.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0bca2376bd42..7b41d1290783 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -307,27 +307,31 @@ static unsigned long highmem_dirtyable_memory(unsigned long total) { #ifdef CONFIG_HIGHMEM int node; - unsigned long x = 0; + unsigned long x; int i; - unsigned long dirtyable = atomic_read(&highmem_file_pages); + unsigned long dirtyable = 0; for_each_node_state(node, N_HIGH_MEMORY) { for (i = ZONE_NORMAL + 1; i < MAX_NR_ZONES; i++) { struct zone *z; + unsigned long nr_pages; if (!is_highmem_idx(i)) continue; z = &NODE_DATA(node)->node_zones[i]; - dirtyable += zone_page_state(z, NR_FREE_PAGES); + if (!populated_zone(z)) + continue; + nr_pages = zone_page_state(z, NR_FREE_PAGES); /* watch for underflows */ - dirtyable -= min(dirtyable, high_wmark_pages(z)); - - x += dirtyable; + nr_pages -= min(nr_pages, high_wmark_pages(z)); + dirtyable += nr_pages; } } + x = dirtyable + atomic_read(&highmem_file_pages); + /* * Unreclaimable memory (kernel memory or anonymous memory * without swap) can bring down the dirtyable pages below -- 2.6.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-07-13 10:00 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-07-13 10:00 [PATCH 0/4] Follow-up fixes to node-lru series v1 Mel Gorman 2016-07-13 10:00 ` Mel Gorman 2016-07-13 10:00 ` [PATCH 1/4] mm, vmscan: Have kswapd reclaim from all zones if reclaiming and buffer_heads_over_limit -fix Mel Gorman 2016-07-13 10:00 ` Mel Gorman 2016-07-13 13:10 ` Johannes Weiner 2016-07-13 13:10 ` Johannes Weiner 2016-07-14 1:22 ` Minchan Kim 2016-07-14 1:22 ` Minchan Kim 2016-07-13 10:00 ` [PATCH 2/4] mm: vmstat: account per-zone stalls and pages skipped during reclaim -fix Mel Gorman 2016-07-13 10:00 ` Mel Gorman 2016-07-13 13:10 ` Johannes Weiner 2016-07-13 13:10 ` Johannes Weiner 2016-07-14 14:45 ` Vlastimil Babka 2016-07-14 14:45 ` Vlastimil Babka 2016-07-13 10:00 ` Mel Gorman [this message] 2016-07-13 10:00 ` [PATCH 3/4] mm, page_alloc: fix dirtyable highmem calculation Mel Gorman 2016-07-13 13:15 ` Johannes Weiner 2016-07-13 13:15 ` Johannes Weiner 2016-07-14 15:22 ` Vlastimil Babka 2016-07-14 15:22 ` Vlastimil Babka 2016-07-13 10:00 ` [PATCH 4/4] mm: move most file-based accounting to the node -fix Mel Gorman 2016-07-13 10:00 ` Mel Gorman 2016-07-13 13:16 ` Johannes Weiner 2016-07-13 13:16 ` Johannes Weiner
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