From 8311c29d40235062a843f4a8e8a70a44af6fe4c9 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 4 Mar 2008 14:29:30 -0800 Subject: md: reduce CPU wastage on idle md array with a write-intent bitmap On an md array with a write-intent bitmap, a thread wakes up every few seconds and scans the bitmap looking for work to do. If the array is idle, there will be no work to do, but a lot of scanning is done to discover this. So cache the fact that the bitmap is completely clean, and avoid scanning the whole bitmap when the cache is known to be clean. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/raid/bitmap.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/raid') diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h index e51b531cd0b2..47fbcba11850 100644 --- a/include/linux/raid/bitmap.h +++ b/include/linux/raid/bitmap.h @@ -235,6 +235,8 @@ struct bitmap { unsigned long flags; + int allclean; + unsigned long max_write_behind; /* write-behind mode */ atomic_t behind_writes; -- cgit v1.2.3 From d0fae18f1b53a1d39135a968792be034bdf7ff26 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 4 Mar 2008 14:29:31 -0800 Subject: md: clean up irregularity with raid autodetect When a raid1 array is stopped, all components currently get added to the list for auto-detection. However we should really only add components that were found by autodetection in the first place. So add a flag to record that information, and use it. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/raid/md_k.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/raid') diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h index 85a068bab625..7bb6d1abf71e 100644 --- a/include/linux/raid/md_k.h +++ b/include/linux/raid/md_k.h @@ -83,6 +83,7 @@ struct mdk_rdev_s #define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */ #define AllReserved 6 /* If whole device is reserved for * one array */ +#define AutoDetected 7 /* added by auto-detect */ int desc_nr; /* descriptor index in the superblock */ int raid_disk; /* role of device in array */ -- cgit v1.2.3