On Tue, 8 May 2007, Neil Brown wrote:

On Tuesday May 8, [EMAIL PROTECTED] wrote:
Kernel: 2.6.21.1

Here is the bug:

md2: RAID1 (works fine)
md3: RAID5 (only syncs at the sync_speed_min set by the kernel)

If I do not run this command:
echo 55000 > /sys/block/md3/md/sync_speed_min

I will get 2 megabytes per second check speed for RAID 5.

I can only reproduce this if I set the stripe_cache_size somewhat
larger than the default of 256 - did you do this?

This code (is_mddev_idle) has always been a bit fragile, particularly
so since the block layer started account IO when it finished rather
than when it started.

This patch might help though.  Let me know if it does what you expect.

Thanks,
NeilBrown


Signed-off-by: Neil Brown <[EMAIL PROTECTED]>

### Diffstat output
./drivers/md/md.c |    2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff .prev/drivers/md/md.c ./drivers/md/md.c
--- .prev/drivers/md/md.c       2007-05-07 17:47:15.000000000 +1000
+++ ./drivers/md/md.c   2007-05-08 22:57:51.000000000 +1000
@@ -5095,7 +5095,7 @@ static int is_mddev_idle(mddev_t *mddev)
                 *
                 * Note: the following is an unsigned comparison.
                 */
-               if ((curr_events - rdev->last_events + 4096) > 8192) {
+               if ((long)curr_events - (long)rdev->last_events > 8192) {
                        rdev->last_events = curr_events;
                        idle = 0;
                }
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html


I can only reproduce this if I set the stripe_cache_size somewhat
larger than the default of 256 - did you do this?
Yes, upon bootup I use:
echo 16384 > /sys/block/md3/md/stripe_cache_size

I have applied this patch and will test it now.

Justin.

-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to