Date: Mon, 4 Oct 2004 11:38:54 -0400 From: David Schultz <das@FreeBSD.ORG> To: John Baldwin <jhb@FreeBSD.ORG> Cc: cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/sys/kern kern_fork.c Message-ID: <20041004153854.GA14022@VARK.MIT.EDU> In-Reply-To: <200410041034.32221.jhb@FreeBSD.org> References: <200410010501.i9151US7086474@repoman.freebsd.org> <200410041034.32221.jhb@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Oct 04, 2004, John Baldwin wrote: > On Friday 01 October 2004 01:01 am, David Schultz wrote: > > das 2004-10-01 05:01:29 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/kern kern_fork.c > > Log: > > Avoid calling _PHOLD(p1) with p2's lock held, since _PHOLD() > > may block to swap in p1. Instead, call _PHOLD earlier, at a > > point where the only lock held happens to be p1's. > > FWIW, I don't think this can actually happen because curthread belonging to p1 > is executing and it wouldn't be executing unless it was swapped in, so I > don't think that PHOLD could ever have blocked. Yes, you're right. I'll revert this one. Shall I also change the _PHOLD() into simply p1->p_lock++ (and similarly for _PRELE()) to avoid the useless test?
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20041004153854.GA14022>