Re: [PATCH 002 of 2] md: Improve the is_mddev_idle test

From: Andrew Morton
Date: Thu May 10 2007 - 03:33:26 EST


On Thu, 10 May 2007 16:22:31 +1000 NeilBrown <neilb@xxxxxxx> wrote:

> The test currently looks for any (non-fuzz) difference, either
> positive or negative. This clearly is not needed. Any non-sync
> activity will cause the total sectors to grow faster than the sync_io
> count (never slower) so we only need to look for a positive differences.
>
> ...
>
> --- .prev/drivers/md/md.c 2007-05-10 15:51:54.000000000 +1000
> +++ ./drivers/md/md.c 2007-05-10 16:05:10.000000000 +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 > 4096) {
> rdev->last_events = curr_events;
> idle = 0;

In which case would unsigned counters be more appropriate?
-
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