From owner-freebsd-hackers Wed Mar 21 11:34: 0 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from earth.backplane.com (earth.backplane.com [208.161.114.65]) by hub.freebsd.org (Postfix) with ESMTP id F20BB37B765; Wed, 21 Mar 2001 11:33:29 -0800 (PST) (envelope-from dillon@earth.backplane.com) Received: (from dillon@localhost) by earth.backplane.com (8.11.2/8.9.3) id f2LIHR416007; Wed, 21 Mar 2001 10:17:27 -0800 (PST) (envelope-from dillon) Date: Wed, 21 Mar 2001 10:17:27 -0800 (PST) From: Matt Dillon Message-Id: <200103211817.f2LIHR416007@earth.backplane.com> To: "Michael C . Wu" Cc: Rik van Riel , Peter Wemm , Alfred Perlstein , "Michael C . Wu" , izero@ms26.hinet.net, cross@math.psu.edu, grog@FreeBSD.ORG, fs@FreeBSD.ORG, hackers@FreeBSD.ORG Subject: Re: tuning a VERY heavily (30.0) loaded s cerver References: <200103211114.f2LBE0h57371@mobile.wemm.org> <20010321120620.A932@peorth.iteration.net> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :B) Added 3gb of swap on one drive, 1gb of swap on a raid volume : another 1gb swap on another raid volume :C) enabled vfs.vmiodirenable and kern.ipc.shm_use_phys : :-- :+-----------------------------------------------------------+ :| keichii@iteration.net | keichii@freebsd.org | I'd reduce that 3gb on that one drive to 1gb. The kernel allocates a bitmap for 4 * (largest_swap_partition), i.e. it will allocate a bitmap for 3gb x 4 = 12 gb worth of swap, even though you only have 5. If you reduce the 3gb to 1gb, then the kernel will allocate a bitmap for 1gb x 4 = 4gb worth of swap, using 1/3 the memory for the bitmap. Each page of swap eats 2 bits of memory for the bitmap so we aren't talking about a huge amount of memory, but it's worth doing. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message