Date: Sat, 15 Feb 2003 18:10:41 -0500 From: Jake Burkholder <jake@locore.ca> To: Tim Robbins <tjr@FreeBSD.ORG> Cc: freebsd-smp@FreeBSD.ORG Subject: Re: Locking down itimers Message-ID: <20030215181041.K63597@locore.ca> In-Reply-To: <20030215154024.A53601@dilbert.robbins.dropbear.id.au>; from tjr@FreeBSD.ORG on Sat, Feb 15, 2003 at 03:40:24PM %2B1100 References: <20030215154024.A53601@dilbert.robbins.dropbear.id.au>
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Apparently, On Sat, Feb 15, 2003 at 03:40:24PM +1100, Tim Robbins said words to the effect of; > This patch protects p_realtimer with the proc mutex instead of Giant, > and obtains sched_lock around accesses to p_stats->p_timer[] to avoid > a potential race with hardclock. It makes getitimer(), setitimer() > and the realitexpire() callout MP-safe. > > It was necessary to restructure setitimer() a bit to guarantee that > the swap: > ovalue = p_realtimer, p_realtimer = value; > occurs atomically with respect to other threads in the same process > calling setitimer() and the callout. > > Does the patch seem reasonable? Any comments? Looks reasonable to me. Jake To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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