From owner-freebsd-smp Mon Apr 30 19:58:57 2001 Delivered-To: freebsd-smp@freebsd.org Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16]) by hub.freebsd.org (Postfix) with ESMTP id 19EC337B423; Mon, 30 Apr 2001 19:58:54 -0700 (PDT) (envelope-from bde@zeta.org.au) Received: from bde.zeta.org.au (bde.zeta.org.au [203.2.228.102]) by mailman.zeta.org.au (8.9.3/8.8.7) with ESMTP id MAA09241; Tue, 1 May 2001 12:58:50 +1000 Date: Tue, 1 May 2001 12:57:44 +1000 (EST) From: Bruce Evans X-Sender: bde@besplex.bde.org To: John Baldwin Cc: Alfred Perlstein , smp@FreeBSD.ORG, Jake Burkholder Subject: Re: that vm diff now makes it into single user mode. In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Mon, 30 Apr 2001, John Baldwin wrote: > On 29-Apr-01 Alfred Perlstein wrote: > > * Jake Burkholder [010428 23:10] wrote: > >> > >> i386/i386/vm_machdep.c: > >> > >> the mtx_trylock in vm_page_zero_idle is unnecessary, the lock is > >> already held. This whole thing needs to be non-blocking if its > >> going to be called from the idle loop, but I'm not sure that > >> that's still possible. Its currently commented out. > > > > Ok, should be fixed. I guess we now know where it could have been > > useful to be able to spin on a sleeplock, ie not worry about > > idle getting stuck on a runqueue/sleepqueue. > > Having the idle process hold locks that other threads block on can really start > wreaking havoc when you throw priority propagation into the mix. It would be > best to push the page zeroing off into a very low priority kernel thread or > something. Why would that do more than move the problem (if any)? Priority propagation should allow the low-priority idle process to become high prority so that it can release its locks as necessary just as well as it allows this for any other low-priority process. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message