[PATCH] count bounce buffer pages in vmstat
This is a patch for counting the number of pages for bounce buffers. It's
shown in /proc/vmstat.
Currently, the number of bounce pages are not counted anywhere. So, if
there are many bounce pages, it seems that there are leaked pages. And
it's difficult for a user to imagine the usage of bounce pages. So, it's
meaningful to show # of bouce pages.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 6b74fcf..39ab8c6 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -131,6 +131,7 @@
unsigned long allocstall; /* direct reclaim calls */
unsigned long pgrotated; /* pages rotated to tail of the LRU */
+ unsigned long nr_bounce; /* pages for bounce buffers */
};
extern void get_page_state(struct page_state *ret);
diff --git a/mm/highmem.c b/mm/highmem.c
index d012765..4009115 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -325,6 +325,7 @@
continue;
mempool_free(bvec->bv_page, pool);
+ dec_page_state(nr_bounce);
}
bio_endio(bio_orig, bio_orig->bi_size, err);
@@ -405,6 +406,7 @@
to->bv_page = mempool_alloc(pool, q->bounce_gfp);
to->bv_len = from->bv_len;
to->bv_offset = from->bv_offset;
+ inc_page_state(nr_bounce);
if (rw == WRITE) {
char *vto, *vfrom;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 04a35b3..80ce7f2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1897,6 +1897,7 @@
"allocstall",
"pgrotated",
+ "nr_bounce",
};
static void *vmstat_start(struct seq_file *m, loff_t *pos)