From owner-cvs-src@FreeBSD.ORG Wed Aug 27 20:42:07 2003 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6789C16A4BF; Wed, 27 Aug 2003 20:42:07 -0700 (PDT) Received: from ns1.xcllnt.net (209-128-86-226.BAYAREA.NET [209.128.86.226]) by mx1.FreeBSD.org (Postfix) with ESMTP id E401A43F75; Wed, 27 Aug 2003 20:42:05 -0700 (PDT) (envelope-from marcel@xcllnt.net) Received: from athlon.pn.xcllnt.net (athlon.pn.xcllnt.net [192.168.4.3]) by ns1.xcllnt.net (8.12.9/8.12.9) with ESMTP id h7S3g3wO036671; Wed, 27 Aug 2003 20:42:03 -0700 (PDT) (envelope-from marcel@piii.pn.xcllnt.net) Received: from athlon.pn.xcllnt.net (localhost [127.0.0.1]) by athlon.pn.xcllnt.net (8.12.9/8.12.9) with ESMTP id h7S3g3fU007853; Wed, 27 Aug 2003 20:42:03 -0700 (PDT) (envelope-from marcel@athlon.pn.xcllnt.net) Received: (from marcel@localhost) by athlon.pn.xcllnt.net (8.12.9/8.12.9/Submit) id h7S3g3RH007852; Wed, 27 Aug 2003 20:42:03 -0700 (PDT) (envelope-from marcel) Date: Wed, 27 Aug 2003 20:42:03 -0700 From: Marcel Moolenaar To: Jeff Roberson Message-ID: <20030828034203.GB7763@athlon.pn.xcllnt.net> References: <20030828031421.GA7763@athlon.pn.xcllnt.net> <20030827231807.I12093-100000@mail.chesapeake.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030827231807.I12093-100000@mail.chesapeake.net> User-Agent: Mutt/1.5.4i cc: cvs-src@FreeBSD.org cc: src-committers@FreeBSD.org cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/fs/specfs spec_vnops.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Aug 2003 03:42:07 -0000 On Wed, Aug 27, 2003 at 11:20:31PM -0400, Jeff Roberson wrote: > On Wed, 27 Aug 2003, Marcel Moolenaar wrote: > > > On Wed, Aug 27, 2003 at 10:55:13PM -0400, Jeff Roberson wrote: > > > On Wed, 27 Aug 2003, Marcel Moolenaar wrote: > > > > > > > marcel 2003/08/27 18:52:14 PDT > > > > > > > > FreeBSD src repository > > > > > > > > Modified files: > > > > sys/fs/specfs spec_vnops.c > > > > Log: > > > > The valid field in struct vm_page can be of type unsigned long when > > > > 32K pages are selected. In spec_getpages() change the printf format > > > > specifier and add an explicit cast so that we always print the field > > > > as a long type. > > > > > > > > Revision Changes Path > > > > 1.209 +2 -2 src/sys/fs/specfs/spec_vnops.c > > > > > > Are you aware of the UMA problems with 32k pages? > > > > No, what are the problems? > > > > It uses an 8 bit index to identify individual items in a slab. This is to > save space in place of the full pointer that is used in traditional slab > allocators. With an 8 bit index your smallest allocation on 4k pages is > 16 bytes and 32 bytes on 8k. It'd be 128 bytes on 32k. You're going to > have to conditionally compile UMA with 16bit indexes. Ah, ok. This is not specific to 32K pages, really. It's just that the internal fragmentation tends to reach unacceptable levels when the page size is too large. Have you measured the space overhead of using 16-bit indexes as compared to using 8-bit indexes? -- Marcel Moolenaar USPA: A-39004 marcel@xcllnt.net