writeback: account per-bdi accumulated written pages

Introduce the BDI_WRITTEN counter. It will be used for estimating the bdi's write bandwidth. Peter Zijlstra <[email protected]>: Move BDI_WRITTEN accounting into __bdi_writeout_inc(). This will cover and fix fuse, which only calls bdi_writeout_inc(). CC: Michael Rubin <[email protected]> Reviewed-by: KOSAKI Motohiro <[email protected]> Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Wu Fengguang <[email protected]>
caferrari · Jul 10, 2011 · f7d2b1e · f7d2b1e
1 parent d46db3d
commit f7d2b1e
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Showing 3 changed files with 10 additions and 2 deletions.
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
@@ -40,6 +40,7 @@ typedef int (congested_fn)(void *, int);
 enum bdi_stat_item {
 	BDI_RECLAIMABLE,
 	BDI_WRITEBACK,
+	BDI_WRITTEN,
 	NR_BDI_STAT_ITEMS
 };
 

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
@@ -97,15 +97,21 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
 		   "BdiDirtyThresh:   %8lu kB\n"
 		   "DirtyThresh:      %8lu kB\n"
 		   "BackgroundThresh: %8lu kB\n"
+		   "BdiWritten:       %8lu kB\n"
 		   "b_dirty:          %8lu\n"
 		   "b_io:             %8lu\n"
 		   "b_more_io:        %8lu\n"
 		   "bdi_list:         %8u\n"
 		   "state:            %8lx\n",
 		   (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)),
 		   (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)),
-		   K(bdi_thresh), K(dirty_thresh),
-		   K(background_thresh), nr_dirty, nr_io, nr_more_io,
+		   K(bdi_thresh),
+		   K(dirty_thresh),
+		   K(background_thresh),
+		   (unsigned long) K(bdi_stat(bdi, BDI_WRITTEN)),
+		   nr_dirty,
+		   nr_io,
+		   nr_more_io,
 		   !list_empty(&bdi->bdi_list), bdi->state);
 #undef K
 

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
@@ -219,6 +219,7 @@ int dirty_bytes_handler(struct ctl_table *table, int write,
  */
 static inline void __bdi_writeout_inc(struct backing_dev_info *bdi)
 {
+	__inc_bdi_stat(bdi, BDI_WRITTEN);
 	__prop_inc_percpu_max(&vm_completions, &bdi->completions,
 			      bdi->max_prop_frac);
 }