writeback: show bdi write bandwidth in debugfs

Add a "BdiWriteBandwidth" entry and indent others in /debug/bdi/*/stats.

btw, increase digital field width to 10, for keeping the possibly
huge BdiWritten number aligned at least for desktop systems.

Impact: this could break user space tools if they are dumb enough to
depend on the number of white spaces.

CC: Theodore Ts'o <tytso@mit.edu>
CC: Jan Kara <jack@suse.cz>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index a76cdd160277bc733e09f3a63bae40dbc2c7bb1e..ddd0345e2e6dd052d52e8e60fa38dc89991b89a3 100644 (file)
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -92,23 +92,25 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
 
 #define K(x) ((x) << (PAGE_SHIFT - 10))
        seq_printf(m,
-                  "BdiWriteback:     %8lu kB\n"
-                  "BdiReclaimable:   %8lu kB\n"
-                  "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",
+                  "BdiWriteback:       %10lu kB\n"
+                  "BdiReclaimable:     %10lu kB\n"
+                  "BdiDirtyThresh:     %10lu kB\n"
+                  "DirtyThresh:        %10lu kB\n"
+                  "BackgroundThresh:   %10lu kB\n"
+                  "BdiWritten:         %10lu kB\n"
+                  "BdiWriteBandwidth:  %10lu kBps\n"
+                  "b_dirty:            %10lu\n"
+                  "b_io:               %10lu\n"
+                  "b_more_io:          %10lu\n"
+                  "bdi_list:           %10u\n"
+                  "state:              %10lx\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),
                   (unsigned long) K(bdi_stat(bdi, BDI_WRITTEN)),
+                  (unsigned long) K(bdi->write_bandwidth),
                   nr_dirty,
                   nr_io,
                   nr_more_io,