From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: [PATCH 002 of 2] md: Improve the is_mddev_idle test Date: Thu, 10 May 2007 19:46:38 +1000 Message-ID: <17986.59902.831796.721280@notabene.brown> References: <20070510161940.20204.patches@notabene> <1070510062231.20403@suse.de> <20070510003304.c5fc35d2.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from Andrew Morton on Thursday May 10 Sender: linux-raid-owner@vger.kernel.org To: Andrew Morton Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-raid.ids On Thursday May 10, akpm@linux-foundation.org wrote: > On Thu, 10 May 2007 16:22:31 +1000 NeilBrown 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? I guess..... It is really the comparison that I want to be signed, I don't much care about the counted - they are expected to wrap (though they might not). So maybe I really want if ((signed long)(curr_events - rdev->last_events) > 4096) { to make it clear... But people expect number to be signed by default, so that probably isn't necessary. Yeah, I'll make them signed one day. Thanks, NeilBrown