Re: [PATCH 4/4] writeback: Reporting dirty thresholds in /proc/vmstat
From: KOSAKI Motohiro <hidden>
Date: 2010-08-30 00:28:33
Also in:
linux-fsdevel, lkml
The kernel already exposes the user desired thresholds in /proc/sys/vm
with dirty_background_ratio and background_ratio. But the kernel may
alter the number requested without giving the user any indication that
is the case.
Knowing the actual ratios the kernel is honoring can help app developers
understand how their buffered IO will be sent to the disk.
$ grep threshold /proc/vmstat
nr_dirty_threshold 409111
nr_dirty_background_threshold 818223? afaict, you and wu agreed /debug/bdi/default/stats is enough good. why do you change your mention?
quoted hunk ↗ jump to hunk
Signed-off-by: Michael Rubin <redacted> --- include/linux/mmzone.h | 2 ++ mm/vmstat.c | 5 +++++ 2 files changed, 7 insertions(+), 0 deletions(-)diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index d42f179..ad48963 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h@@ -106,6 +106,8 @@ enum zone_stat_item { NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ NR_FILE_PAGES_DIRTIED, /* number of times pages get dirtied */ NR_PAGES_CLEANED, /* number of times pages enter writeback */ + NR_DIRTY_THRESHOLD, /* writeback threshold */ + NR_DIRTY_BG_THRESHOLD, /* bg writeback threshold */
Don't need this even though we add this two fields into /proc/sys/vm. It can be calculated at displaing time.
quoted hunk ↗ jump to hunk
#ifdef CONFIG_NUMA NUMA_HIT, /* allocated in intended node */ NUMA_MISS, /* allocated in non intended node */diff --git a/mm/vmstat.c b/mm/vmstat.c index 8521475..2342010 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c@@ -17,6 +17,7 @@ #include <linux/vmstat.h> #include <linux/sched.h> #include <linux/math64.h> +#include <linux/writeback.h> #ifdef CONFIG_VM_EVENT_COUNTERS DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};@@ -734,6 +735,8 @@ static const char * const vmstat_text[] = { "nr_shmem", "nr_dirtied", "nr_cleaned", + "nr_dirty_threshold", + "nr_dirty_background_threshold", #ifdef CONFIG_NUMA "numa_hit",@@ -917,6 +920,8 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos) return ERR_PTR(-ENOMEM); for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) v[i] = global_page_state(i); + + global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD, v + NR_DIRTY_THRESHOLD); #ifdef CONFIG_VM_EVENT_COUNTERS e = v + NR_VM_ZONE_STAT_ITEMS; all_vm_events(e);-- 1.7.1
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