tree b9f55833c83a41a6e047f0de82b17d9753ad0542
parent ee8b81b03dffa1c0075553d01c557714aedb85a1
author Paul Clements <paul.clements@steeleye.com> 1268024557 +1100
committer NeilBrown <neilb@suse.de> 1274160466 +1000

md: expose max value of behind writes counter

Keep track of the maximum number of concurrent write-behind requests
for an md array and exposed this number in sysfs at
   md/bitmap/max_backlog_used

Writing any value to this file will clear it.

This allows userspace to be involved in tuning bitmap/backlog.

Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: NeilBrown <neilb@suse.de>