Re: [PATCH 3/5] writeback: nr_dirtied and nr_written in/proc/vmstat

From: Andrew Morton
Date: Mon Sep 13 2010 - 17:21:13 EST


On Sun, 12 Sep 2010 22:58:11 -0700
Michael Rubin <mrubin@xxxxxxxxxx> wrote:

> To help developers and applications gain visibility into writeback
> behaviour adding two entries to vm_stat_items and /proc/vmstat. This
> will allow us to track the "written" and "dirtied" counts.
>
> # grep nr_dirtied /proc/vmstat
> nr_dirtied 3747
> # grep nr_written /proc/vmstat
> nr_written 3618
>
> Signed-off-by: Michael Rubin <mrubin@xxxxxxxxxx>
> Reviewed-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
> ---
> include/linux/mmzone.h | 2 ++
> mm/page-writeback.c | 2 ++
> mm/vmstat.c | 3 +++
> 3 files changed, 7 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index 6e6e626..d0d7454 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -104,6 +104,8 @@ enum zone_stat_item {
> 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) */
> + NR_FILE_DIRTIED, /* accumulated dirty pages */
> + NR_WRITTEN, /* accumulated written pages */

I think we can make those comments less ambiguous>

--- a/include/linux/mmzone.h
+++ a/include/linux/mmzone.h
@@ -104,8 +104,8 @@ enum zone_stat_item {
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) */
- NR_FILE_DIRTIED, /* accumulated dirty pages */
- NR_WRITTEN, /* accumulated written pages */
+ NR_FILE_DIRTIED, /* page dirtyings since bootup */
+ NR_WRITTEN, /* page writings since bootup */
#ifdef CONFIG_NUMA
NUMA_HIT, /* allocated in intended node */
NUMA_MISS, /* allocated in non intended node */

>
> ...
>
> index f389168..d448ef4 100644
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -732,6 +732,9 @@ static const char * const vmstat_text[] = {
> "nr_isolated_anon",
> "nr_isolated_file",
> "nr_shmem",
> + "nr_dirtied",
> + "nr_written",
> +

The mismatch between "NR_FILE_DIRTIED" and "nr_dirtied" is a bit, umm,
dirty. I can kinda see the logic in the naming but still..

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/