Date: Fri, 30 Jul 2004 15:32:24 -0400 From: John Baldwin <jhb@FreeBSD.org> To: Brian Fundakowski Feldman <green@FreeBSD.org> Cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/vm vm_map.c vm_map.h Message-ID: <200407301532.24968.jhb@FreeBSD.org> In-Reply-To: <20040730160645.GB33220@green.homeunix.org> References: <200407300910.i6U9ASg5077534@repoman.freebsd.org> <20040730160645.GB33220@green.homeunix.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Friday 30 July 2004 12:06 pm, Brian Fundakowski Feldman wrote: > On Fri, Jul 30, 2004 at 09:10:28AM +0000, Maxime Henrion wrote: > > mux 2004-07-30 09:10:28 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/vm vm_map.c vm_map.h > > Log: > > Get rid of another lockmgr(9) consumer by using sx locks for the user > > maps. We always acquire the sx lock exclusively here, but we can't > > use a mutex because we want to be able to sleep while holding the > > lock. This is completely equivalent to what we were doing with the > > lockmgr(9) locks before. > > Not that I don't think it's worth doing in general, but is there a > comparison anyone has done between speeds of sx and lockmgr? Speed aside, when allproc_lock and proctree_lock were lockmgr locks (before sx was implemented), my SMP machines routinely locked up and when I looked at things in the debugger it seemed that no one held allproc_lock but several processes were blocked on it. Quite frankly, I don't trust lockmgr()'s implementation. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200407301532.24968.jhb>