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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2007-10-16 23:25:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-17 08:42:45 -0700 |
| commit | b2e8fb6efa209c82203c79b491b5bc952d44aa57 (patch) | |
| tree | e4c82e3f2c70a188ced7126435bf153f5f6c4a1c /mm/backing-dev.c | |
| parent | e0bf68ddec4f4f90e5871404be4f1854c17f3120 (diff) | |
| download | lwn-b2e8fb6efa209c82203c79b491b5bc952d44aa57.tar.gz lwn-b2e8fb6efa209c82203c79b491b5bc952d44aa57.zip | |
mm: scalable bdi statistics counters
Provide scalable per backing_dev_info statistics counters.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/backing-dev.c')
| -rw-r--r-- | mm/backing-dev.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 841901a95595..a47065e084a4 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -5,6 +5,33 @@ #include <linux/sched.h> #include <linux/module.h> +int bdi_init(struct backing_dev_info *bdi) +{ + int i, j; + int err; + + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) { + err = percpu_counter_init_irq(&bdi->bdi_stat[i], 0); + if (err) { + for (j = 0; j < i; j++) + percpu_counter_destroy(&bdi->bdi_stat[i]); + break; + } + } + + return err; +} +EXPORT_SYMBOL(bdi_init); + +void bdi_destroy(struct backing_dev_info *bdi) +{ + int i; + + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) + percpu_counter_destroy(&bdi->bdi_stat[i]); +} +EXPORT_SYMBOL(bdi_destroy); + static wait_queue_head_t congestion_wqh[2] = { __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]), __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1]) |