[RFC][PATCH 4/6] mm: count unstable pages per BDI

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

[-- Attachment #1: bdi_stat_unstable.patch --]
[-- Type: text/plain, Size: 2019 bytes --]

Count per BDI unstable pages.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 fs/nfs/write.c              |    4 ++++
 include/linux/backing-dev.h |    1 +
 2 files changed, 5 insertions(+)

Index: linux-2.6/fs/nfs/write.c
===================================================================
--- linux-2.6.orig/fs/nfs/write.c
+++ linux-2.6/fs/nfs/write.c
@@ -474,6 +474,7 @@ 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);
 	__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
 }
 #endif
@@ -545,6 +546,7 @@ 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);
 		nfs_list_remove_request(req);
 		nfs_inode_remove_request(req);
 		nfs_unlock_request(req);
@@ -1278,6 +1280,7 @@ 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);
 		nfs_clear_page_writeback(req);
 	}
 	return -ENOMEM;
@@ -1302,6 +1305,7 @@ 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);
 
 		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
+++ linux-2.6/include/linux/backing-dev.h
@@ -25,6 +25,7 @@ enum bdi_state {
 enum bdi_stat_item {
 	BDI_DIRTY,
 	BDI_WRITEBACK,
+	BDI_UNSTABLE,
 	NR_BDI_STAT_ITEMS
 };
 

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