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authorPaul Clements <paul.clements@steeleye.com>2010-03-08 16:02:37 +1100
committerNeilBrown <neilb@suse.de>2010-05-18 15:27:46 +1000
commit696fcd535b5a8cfc0617e9cf1d9d69a13895cc1e (patch)
treeb9f55833c83a41a6e047f0de82b17d9753ad0542 /drivers/md/bitmap.h
parentee8b81b03dffa1c0075553d01c557714aedb85a1 (diff)
downloadop-kernel-dev-696fcd535b5a8cfc0617e9cf1d9d69a13895cc1e.zip
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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>
Diffstat (limited to 'drivers/md/bitmap.h')
-rw-r--r--drivers/md/bitmap.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index cb821d7..aa82b7c 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -227,6 +227,7 @@ struct bitmap {
int allclean;
atomic_t behind_writes;
+ unsigned long behind_writes_used; /* highest actual value at runtime */
/*
* the bitmap daemon - periodically wakes up and sweeps the bitmap
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