[PATCH 17/23] mm: count writeback pages per BDI

Peter Zijlstra
2007-08-03T12:37:30Z

[-- Attachment #1: bdi_stat_writeback.patch --]
[-- Type: text/plain, Size: 2155 bytes --]

Count per BDI writeback pages.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
include/linux/backing-dev.h | 1 +
mm/page-writeback.c | 12 ++++++++++--
2 files changed, 11 insertions(+), 2 deletions(-)

Index: linux-2.6/mm/page-writeback.c
===================================================================
--- linux-2.6.orig/mm/page-writeback.c
+++ linux-2.6/mm/page-writeback.c
@@ -981,14 +981,18 @@ int test_clear_page_writeback(struct pag
int ret;

if (mapping) {
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
unsigned long flags;

write_lock_irqsave(&mapping->tree_lock, flags);
ret = TestClearPageWriteback(page);
- if (ret)
+ if (ret) {
radix_tree_tag_clear(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_WRITEBACK);
+ if (bdi_cap_writeback_dirty(bdi))
+ __dec_bdi_stat(bdi, BDI_WRITEBACK);
+ }
write_unlock_irqrestore(&mapping->tree_lock, flags);
} else {
ret = TestClearPageWriteback(page);
@@ -1004,14 +1008,18 @@ int test_set_page_writeback(struct page
int ret;

if (mapping) {
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
unsigned long flags;

write_lock_irqsave(&mapping->tree_lock, flags);
ret = TestSetPageWriteback(page);
- if (!ret)
+ if (!ret) {
radix_tree_tag_set(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_WRITEBACK);
+ if (bdi_cap_writeback_dirty(bdi))
+ __inc_bdi_stat(bdi, BDI_WRITEBACK);
+ }
if (!PageDirty(page))
radix_tree_tag_clear(&mapping->page_tree,
page_index(page),
Index: linux-2.6/include/linux/backing-dev.h
===================================================================
--- linux-2.6.orig/include/linux/backing-dev.h
+++ linux-2.6/include/linux/backing-dev.h
@@ -28,6 +28,7 @@ typedef int (congested_fn)(void *, int);

enum bdi_stat_item {
BDI_RECLAIMABLE,
+ BDI_WRITEBACK,
NR_BDI_STAT_ITEMS
};