[PATCH 24/49] writeback: attribute stats to the matching per-cgroup bdi_writeback

Tejun Heo
2015-04-06T20:16:56Z

Until now, all WB_* stats were accounted against the root wb
(bdi_writeback), now that multiple wb (bdi_writeback) support is in
place, let's attributes the stats to the respective per-cgroup wb's.

As no filesystem has FS_CGROUP_WRITEBACK yet, this doesn't lead to
visible behavior differences.

v2: Updated for per-inode wb association.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
---
mm/filemap.c | 2 +-
mm/page-writeback.c | 22 ++++++++++++++--------
mm/truncate.c | 6 ++++--
3 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index a2b098b..64698fa 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -215,7 +215,7 @@ void __delete_from_page_cache(struct page *page, void *shadow,
if (PageDirty(page) && mapping_cap_account_dirty(mapping)) {
mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
dec_zone_page_state(page, NR_FILE_DIRTY);
- dec_wb_stat(&inode_to_bdi(mapping->host)->wb, WB_RECLAIMABLE);
+ dec_wb_stat(inode_to_wb(mapping->host), WB_RECLAIMABLE);
}
}

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 79c9026..3b6d058 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2175,10 +2175,13 @@ EXPORT_SYMBOL(__set_page_dirty_nobuffers);
void account_page_redirty(struct page *page)
{
struct address_space *mapping = page->mapping;
+
if (mapping && mapping_cap_account_dirty(mapping)) {
+ struct bdi_writeback *wb = inode_to_wb(mapping->host);
+
current->nr_dirtied--;
dec_zone_page_state(page, NR_DIRTIED);
- dec_wb_stat(&inode_to_bdi(mapping->host)->wb, WB_DIRTIED);
+ dec_wb_stat(wb, WB_DIRTIED);
}
}
EXPORT_SYMBOL(account_page_redirty);
@@ -2324,8 +2327,7 @@ int clear_page_dirty_for_io(struct page *page)
if (TestClearPageDirty(page)) {
mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
dec_zone_page_state(page, NR_FILE_DIRTY);
- dec_wb_stat(&inode_to_bdi(mapping->host)->wb,
- WB_RECLAIMABLE);
+ dec_wb_stat(inode_to_wb(mapping->host), WB_RECLAIMABLE);
ret = 1;
}
mem_cgroup_end_page_stat(memcg);
@@ -2343,7 +2345,8 @@ int test_clear_page_writeback(struct page *page)

memcg = mem_cgroup_begin_page_stat(page);
if (mapping) {
- struct backing_dev_info *bdi = inode_to_bdi(mapping->host);
+ struct inode *inode = mapping->host;
+ struct backing_dev_info *bdi = inode_to_bdi(inode);
unsigned long flags;

spin_lock_irqsave(&mapping->tree_lock, flags);
@@ -2353,8 +2356,10 @@ int test_clear_page_writeback(struct page *page)
page_index(page),
PAGECACHE_TAG_WRITEBACK);
if (bdi_cap_account_writeback(bdi)) {
- __dec_wb_stat(&bdi->wb, WB_WRITEBACK);
- __wb_writeout_inc(&bdi->wb);
+ struct bdi_writeback *wb = inode_to_wb(inode);
+
+ __dec_wb_stat(wb, WB_WRITEBACK);
+ __wb_writeout_inc(wb);
}
}
spin_unlock_irqrestore(&mapping->tree_lock, flags);
@@ -2378,7 +2383,8 @@ int __test_set_page_writeback(struct page *page, bool keep_write)

memcg = mem_cgroup_begin_page_stat(page);
if (mapping) {
- struct backing_dev_info *bdi = inode_to_bdi(mapping->host);
+ struct inode *inode = mapping->host;
+ struct backing_dev_info *bdi = inode_to_bdi(inode);
unsigned long flags;

spin_lock_irqsave(&mapping->tree_lock, flags);
@@ -2388,7 +2394,7 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
page_index(page),
PAGECACHE_TAG_WRITEBACK);
if (bdi_cap_account_writeback(bdi))
- __inc_wb_stat(&bdi->wb, WB_WRITEBACK);
+ __inc_wb_stat(inode_to_wb(inode), WB_WRITEBACK);
}
if (!PageDirty(page))
radix_tree_tag_clear(&mapping->page_tree,
diff --git a/mm/truncate.c b/mm/truncate.c
index df16f8c..fe2d769 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -113,11 +113,13 @@ void cancel_dirty_page(struct page *page, unsigned int account_size)
memcg = mem_cgroup_begin_page_stat(page);
if (TestClearPageDirty(page)) {
struct address_space *mapping = page->mapping;
+
if (mapping && mapping_cap_account_dirty(mapping)) {
+ struct bdi_writeback *wb = inode_to_wb(mapping->host);
+
mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
dec_zone_page_state(page, NR_FILE_DIRTY);
- dec_wb_stat(&inode_to_bdi(mapping->host)->wb,
- WB_RECLAIMABLE);
+ dec_wb_stat(wb, WB_RECLAIMABLE);
if (account_size)
task_io_account_cancelled_write(account_size);
}
--
2.1.0