[PATCH] zoned vm counters: split NR_ANON_PAGES off from NR_FILE_MAPPED
The current NR_FILE_MAPPED is used by zone reclaim and the dirty load
calculation as the number of mapped pagecache pages. However, that is not
true. NR_FILE_MAPPED includes the mapped anonymous pages. This patch
separates those and therefore allows an accurate tracking of the anonymous
pages per zone.
It then becomes possible to determine the number of unmapped pages per zone
and we can avoid scanning for unmapped pages if there are none.
Also it may now be possible to determine the mapped/unmapped ratio in
get_dirty_limit. Isnt the number of anonymous pages irrelevant in that
calculation?
Note that this will change the meaning of the number of mapped pages reported
in /proc/vmstat /proc/meminfo and in the per node statistics. This may affect
user space tools that monitor these counters! NR_FILE_MAPPED works like
NR_FILE_DIRTY. It is only valid for pagecache pages.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/base/node.c b/drivers/base/node.c
index ae9e3fe..c3bf051 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -71,6 +71,7 @@
"Node %d Writeback: %8lu kB\n"
"Node %d FilePages: %8lu kB\n"
"Node %d Mapped: %8lu kB\n"
+ "Node %d AnonPages: %8lu kB\n"
"Node %d Slab: %8lu kB\n",
nid, K(i.totalram),
nid, K(i.freeram),
@@ -85,6 +86,7 @@
nid, K(ps.nr_writeback),
nid, K(node_page_state(nid, NR_FILE_PAGES)),
nid, K(node_page_state(nid, NR_FILE_MAPPED)),
+ nid, K(node_page_state(nid, NR_ANON_PAGES)),
nid, K(ps.nr_slab));
n += hugetlb_report_node_meminfo(nid, buf + n);
return n;
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 1af12fd7..ff80965 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -168,6 +168,7 @@
"SwapFree: %8lu kB\n"
"Dirty: %8lu kB\n"
"Writeback: %8lu kB\n"
+ "AnonPages: %8lu kB\n"
"Mapped: %8lu kB\n"
"Slab: %8lu kB\n"
"CommitLimit: %8lu kB\n"
@@ -191,6 +192,7 @@
K(i.freeswap),
K(ps.nr_dirty),
K(ps.nr_writeback),
+ K(global_page_state(NR_ANON_PAGES)),
K(global_page_state(NR_FILE_MAPPED)),
K(ps.nr_slab),
K(allowed),
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 08be91e..4833abd 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -47,7 +47,8 @@
#endif
enum zone_stat_item {
- NR_FILE_MAPPED, /* mapped into pagetables.
+ NR_ANON_PAGES, /* Mapped anonymous pages */
+ NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
only modified from process context */
NR_FILE_PAGES,
NR_VM_ZONE_STAT_ITEMS };
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 60c7244..0faacfe 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -111,7 +111,8 @@
{
wbs->nr_dirty = read_page_state(nr_dirty);
wbs->nr_unstable = read_page_state(nr_unstable);
- wbs->nr_mapped = global_page_state(NR_FILE_MAPPED);
+ wbs->nr_mapped = global_page_state(NR_FILE_MAPPED) +
+ global_page_state(NR_ANON_PAGES);
wbs->nr_writeback = read_page_state(nr_writeback);
}
diff --git a/mm/rmap.c b/mm/rmap.c
index af5e980..40158b5 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -455,7 +455,7 @@
* nr_mapped state can be updated without turning off
* interrupts because it is not modified via interrupt.
*/
- __inc_zone_page_state(page, NR_FILE_MAPPED);
+ __inc_zone_page_state(page, NR_ANON_PAGES);
}
/**
@@ -531,7 +531,8 @@
*/
if (page_test_and_clear_dirty(page))
set_page_dirty(page);
- __dec_zone_page_state(page, NR_FILE_MAPPED);
+ __dec_zone_page_state(page,
+ PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
}
}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 08bc54e..2f03901 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -742,7 +742,8 @@
* how much memory
* is mapped.
*/
- mapped_ratio = (global_page_state(NR_FILE_MAPPED) * 100) /
+ mapped_ratio = ((global_page_state(NR_FILE_MAPPED) +
+ global_page_state(NR_ANON_PAGES)) * 100) /
vm_total_pages;
/*
diff --git a/mm/vmstat.c b/mm/vmstat.c
index f16b33e..3baf4df 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -395,6 +395,7 @@
static char *vmstat_text[] = {
/* Zoned VM counters */
+ "nr_anon_pages",
"nr_mapped",
"nr_file_pages",
