Re: [PATCH 09/12] mm: count unstable pages per BDI

Peter Zijlstra
2007-04-19T18:46:46Z

On Thu, 2007-04-19 at 20:12 +0200, Peter Zijlstra wrote:
> On Thu, 2007-04-19 at 19:44 +0200, Miklos Szeredi wrote:
> > > Count per BDI unstable pages.
> > >
> >
> > I'm wondering, is it really worth having this category separate from
> > per BDI brity pages?
> >
> > With the exception of the export to sysfs, always the sum of unstable
> > + dirty is used.
>
> I guess you are right, but it offends my sense of aesthetics to break
> symmetry with the zone statistics. However, it has the added advantage
> of only needing 2 deltas as well.

I guess, this should do.

---
fs/buffer.c | 2 +-
fs/nfs/write.c | 11 +++++++----
include/linux/backing-dev.h | 3 +--
mm/page-writeback.c | 16 +++++++---------
mm/truncate.c | 2 +-
5 files changed, 17 insertions(+), 17 deletions(-)

Index: linux-2.6/fs/buffer.c
===================================================================
--- linux-2.6.orig/fs/buffer.c 2007-04-19 19:59:26.000000000 +0200
+++ linux-2.6/fs/buffer.c 2007-04-19 20:35:39.000000000 +0200
@@ -733,7 +733,7 @@ int __set_page_dirty_buffers(struct page
if (page->mapping) { /* Race with truncate? */
if (mapping_cap_account_dirty(mapping)) {
__inc_zone_page_state(page, NR_FILE_DIRTY);
- __inc_bdi_stat(mapping->backing_dev_info, BDI_DIRTY);
+ __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIM);
task_io_account_write(PAGE_CACHE_SIZE);
}
radix_tree_tag_set(&mapping->page_tree,
Index: linux-2.6/fs/nfs/write.c
===================================================================
--- linux-2.6.orig/fs/nfs/write.c 2007-04-19 19:59:26.000000000 +0200
+++ linux-2.6/fs/nfs/write.c 2007-04-19 20:39:03.000000000 +0200
@@ -456,7 +456,7 @@ nfs_mark_request_commit(struct nfs_page
nfsi->ncommit++;
spin_unlock(&nfsi->req_lock);
inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
- inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_UNSTABLE);
+ inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIM);
__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
}
#endif
@@ -518,7 +518,8 @@ static void nfs_cancel_commit_list(struc
while(!list_empty(head)) {
req = nfs_list_entry(head->next);
dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
- dec_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_UNSTABLE);
+ dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
+ BDI_RECLAIM);
nfs_list_remove_request(req);
nfs_inode_remove_request(req);
nfs_unlock_request(req);
@@ -1247,7 +1248,8 @@ nfs_commit_list(struct inode *inode, str
nfs_list_remove_request(req);
nfs_mark_request_commit(req);
dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
- dec_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_UNSTABLE);
+ dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
+ BDI_RECLAIM);
nfs_clear_page_writeback(req);
}
return -ENOMEM;
@@ -1272,7 +1274,8 @@ static void nfs_commit_done(struct rpc_t
req = nfs_list_entry(data->pages.next);
nfs_list_remove_request(req);
dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
- dec_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_UNSTABLE);
+ dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
+ BDI_RECLAIM);

dprintk("NFS: commit (%s/%Ld %d@%Ld)",
req->wb_context->dentry->d_inode->i_sb->s_id,
Index: linux-2.6/include/linux/backing-dev.h
===================================================================
--- linux-2.6.orig/include/linux/backing-dev.h 2007-04-19 19:59:26.000000000 +0200
+++ linux-2.6/include/linux/backing-dev.h 2007-04-19 20:39:24.000000000 +0200
@@ -26,9 +26,8 @@ enum bdi_state {
typedef int (congested_fn)(void *, int);

enum bdi_stat_item {
- BDI_DIRTY,
+ BDI_RECLAIM,
BDI_WRITEBACK,
- BDI_UNSTABLE,
BDI_WRITEOUT,
NR_BDI_STAT_ITEMS
};
Index: linux-2.6/mm/page-writeback.c
===================================================================
--- linux-2.6.orig/mm/page-writeback.c 2007-04-19 20:00:09.000000000 +0200
+++ linux-2.6/mm/page-writeback.c 2007-04-19 20:40:29.000000000 +0200
@@ -300,8 +300,7 @@ static void balance_dirty_pages(struct a

get_dirty_limits(&background_thresh, &dirty_thresh,
&bdi_thresh, bdi);
- bdi_nr_reclaimable = bdi_stat(bdi, BDI_DIRTY) +
- bdi_stat(bdi, BDI_UNSTABLE);
+ bdi_nr_reclaimable = bdi_stat(bdi, BDI_RECLAIM);
bdi_nr_writeback = bdi_stat(bdi, BDI_WRITEBACK);
if (bdi_nr_reclaimable + bdi_nr_writeback <= bdi_thresh)
break;
@@ -321,16 +320,14 @@ static void balance_dirty_pages(struct a
get_dirty_limits(&background_thresh, &dirty_thresh,
&bdi_thresh, bdi);

- if (bdi_thresh < 3*bdi_stat_delta()) {
+ if (bdi_thresh < 2*bdi_stat_delta()) {
bdi_nr_reclaimable =
- bdi_stat_sum(bdi, BDI_DIRTY) +
- bdi_stat_sum(bdi, BDI_UNSTABLE);
+ bdi_stat_sum(bdi, BDI_RECLAIM);
bdi_nr_writeback =
bdi_stat_sum(bdi, BDI_WRITEBACK);
} else {
bdi_nr_reclaimable =
- bdi_stat(bdi, BDI_DIRTY) +
- bdi_stat(bdi, BDI_UNSTABLE);
+ bdi_stat(bdi, BDI_RECLAIM);
bdi_nr_writeback =
bdi_stat(bdi, BDI_WRITEBACK);
}
@@ -907,7 +904,8 @@ int __set_page_dirty_nobuffers(struct pa
BUG_ON(mapping2 != mapping);
if (mapping_cap_account_dirty(mapping)) {
__inc_zone_page_state(page, NR_FILE_DIRTY);
- __inc_bdi_stat(mapping->backing_dev_info, BDI_DIRTY);
+ __inc_bdi_stat(mapping->backing_dev_info,
+ BDI_RECLAIM);
task_io_account_write(PAGE_CACHE_SIZE);
}
radix_tree_tag_set(&mapping->page_tree,
@@ -1034,7 +1032,7 @@ int clear_page_dirty_for_io(struct page
set_page_dirty(page);
if (TestClearPageDirty(page)) {
dec_zone_page_state(page, NR_FILE_DIRTY);
- dec_bdi_stat(mapping->backing_dev_info, BDI_DIRTY);
+ dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIM);
return 1;
}
return 0;
Index: linux-2.6/mm/truncate.c
===================================================================
--- linux-2.6.orig/mm/truncate.c 2007-04-19 19:59:26.000000000 +0200
+++ linux-2.6/mm/truncate.c 2007-04-19 20:40:36.000000000 +0200
@@ -71,7 +71,7 @@ void cancel_dirty_page(struct page *page
struct address_space *mapping = page->mapping;
if (mapping && mapping_cap_account_dirty(mapping)) {
dec_zone_page_state(page, NR_FILE_DIRTY);
- dec_bdi_stat(mapping->backing_dev_info, BDI_DIRTY);
+ dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIM);
if (account_size)
task_io_account_cancelled_write(account_size);