Re: [PATCH 3/3] add isolate pages vmstat

From: Andrew Morton
Date: Wed Jul 15 2009 - 23:17:43 EST


On Thu, 16 Jul 2009 09:55:47 +0900 (JST) KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote:

> ChangeLog
> Since v5
> - Rewrote the description
> - Treat page migration
> Since v4
> - Changed displaing order in show_free_areas() (as Wu's suggested)
> Since v3
> - Fixed misaccount page bug when lumby reclaim occur
> Since v2
> - Separated IsolateLRU field to Isolated(anon) and Isolated(file)
> Since v1
> - Renamed IsolatePages to IsolatedLRU
>
> ==================================
> Subject: [PATCH] add isolate pages vmstat
>
> If the system is running a heavy load of processes then concurrent reclaim
> can isolate a large numbe of pages from the LRU. /proc/meminfo and the
> output generated for an OOM do not show how many pages were isolated.
>
> This patch shows the information about isolated pages.
>
>
> reproduce way
> -----------------------
> % ./hackbench 140 process 1000
> => OOM occur
>
> active_anon:146 inactive_anon:0 isolated_anon:49245
> active_file:79 inactive_file:18 isolated_file:113
> unevictable:0 dirty:0 writeback:0 unstable:0 buffer:39
> free:370 slab_reclaimable:309 slab_unreclaimable:5492
> mapped:53 shmem:15 pagetables:28140 bounce:0
>
>
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> Acked-by: Rik van Riel <riel@xxxxxxxxxx>
> Acked-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
> Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>
> ---
> drivers/base/node.c | 4 ++++
> fs/proc/meminfo.c | 4 ++++
> include/linux/mmzone.h | 2 ++
> mm/migrate.c | 11 +++++++++++
> mm/page_alloc.c | 12 +++++++++---
> mm/vmscan.c | 12 +++++++++++-
> mm/vmstat.c | 2 ++
> 7 files changed, 43 insertions(+), 4 deletions(-)
>
> Index: b/fs/proc/meminfo.c
> ===================================================================
> --- a/fs/proc/meminfo.c
> +++ b/fs/proc/meminfo.c
> @@ -65,6 +65,8 @@ static int meminfo_proc_show(struct seq_
> "Active(file): %8lu kB\n"
> "Inactive(file): %8lu kB\n"
> "Unevictable: %8lu kB\n"
> + "Isolated(anon): %8lu kB\n"
> + "Isolated(file): %8lu kB\n"
> "Mlocked: %8lu kB\n"

Are these counters really important enough to justify being present in
/proc/meminfo? They seem fairly low-level developer-only details.
Perhaps relegate them to /proc/vmstat?

> #ifdef CONFIG_HIGHMEM
> "HighTotal: %8lu kB\n"
> @@ -110,6 +112,8 @@ static int meminfo_proc_show(struct seq_
> K(pages[LRU_ACTIVE_FILE]),
> K(pages[LRU_INACTIVE_FILE]),
> K(pages[LRU_UNEVICTABLE]),
> + K(global_page_state(NR_ISOLATED_ANON)),
> + K(global_page_state(NR_ISOLATED_FILE)),
> K(global_page_state(NR_MLOCK)),
> #ifdef CONFIG_HIGHMEM
> K(i.totalhigh),
> Index: b/include/linux/mmzone.h
> ===================================================================
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -100,6 +100,8 @@ enum zone_stat_item {
> NR_BOUNCE,
> NR_VMSCAN_WRITE,
> NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
> + NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
> + NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
> NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
> #ifdef CONFIG_NUMA
> NUMA_HIT, /* allocated in intended node */
> Index: b/mm/page_alloc.c
> ===================================================================
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2115,16 +2115,18 @@ void show_free_areas(void)
> }
> }
>
> - printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n"
> - " inactive_file:%lu"
> + printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
> + " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
> " unevictable:%lu"
> " dirty:%lu writeback:%lu unstable:%lu buffer:%lu\n"
> " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
> " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
> global_page_state(NR_ACTIVE_ANON),
> - global_page_state(NR_ACTIVE_FILE),
> global_page_state(NR_INACTIVE_ANON),
> + global_page_state(NR_ISOLATED_ANON),
> + global_page_state(NR_ACTIVE_FILE),
> global_page_state(NR_INACTIVE_FILE),
> + global_page_state(NR_ISOLATED_FILE),
> global_page_state(NR_UNEVICTABLE),
> global_page_state(NR_FILE_DIRTY),
> global_page_state(NR_WRITEBACK),
> @@ -2152,6 +2154,8 @@ void show_free_areas(void)
> " active_file:%lukB"
> " inactive_file:%lukB"
> " unevictable:%lukB"
> + " isolated(anon):%lukB"
> + " isolated(file):%lukB"
> " present:%lukB"
> " mlocked:%lukB"
> " dirty:%lukB"
> @@ -2178,6 +2182,8 @@ void show_free_areas(void)
> K(zone_page_state(zone, NR_ACTIVE_FILE)),
> K(zone_page_state(zone, NR_INACTIVE_FILE)),
> K(zone_page_state(zone, NR_UNEVICTABLE)),
> + K(zone_page_state(zone, NR_ISOLATED_ANON)),
> + K(zone_page_state(zone, NR_ISOLATED_FILE)),
> K(zone->present_pages),
> K(zone_page_state(zone, NR_MLOCK)),
> K(zone_page_state(zone, NR_FILE_DIRTY)),
> Index: b/mm/vmscan.c
> ===================================================================
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1067,6 +1067,8 @@ static unsigned long shrink_inactive_lis
> unsigned long nr_active;
> unsigned int count[NR_LRU_LISTS] = { 0, };
> int mode = lumpy_reclaim ? ISOLATE_BOTH : ISOLATE_INACTIVE;
> + unsigned long nr_anon;
> + unsigned long nr_file;
>
> nr_taken = sc->isolate_pages(sc->swap_cluster_max,
> &page_list, &nr_scan, sc->order, mode,
> @@ -1097,6 +1099,10 @@ static unsigned long shrink_inactive_lis
> __mod_zone_page_state(zone, NR_INACTIVE_ANON,
> -count[LRU_INACTIVE_ANON]);
>
> + nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON];
> + nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE];
> + __mod_zone_page_state(zone, NR_ISOLATED_ANON, nr_anon);
> + __mod_zone_page_state(zone, NR_ISOLATED_FILE, nr_file);
>
> reclaim_stat->recent_scanned[0] += count[LRU_INACTIVE_ANON];
> reclaim_stat->recent_scanned[0] += count[LRU_ACTIVE_ANON];
> @@ -1164,6 +1170,9 @@ static unsigned long shrink_inactive_lis
> spin_lock_irq(&zone->lru_lock);
> }
> }
> + __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon);
> + __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file);
> +
> } while (nr_scanned < max_scan);

This is a non-trivial amount of extra stuff. Do we really need it?


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