From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q5BEsxmE104525 for ; Mon, 11 Jun 2012 09:54:59 -0500 Received: from greer.hardwarefreak.com (mo-65-41-216-221.sta.embarqhsd.net [65.41.216.221]) by cuda.sgi.com with ESMTP id KPZgi6oulFMVhv8C for ; Mon, 11 Jun 2012 07:54:58 -0700 (PDT) Received: from [192.168.100.53] (gffx.hardwarefreak.com [192.168.100.53]) by greer.hardwarefreak.com (Postfix) with ESMTP id 1FED16C080 for ; Mon, 11 Jun 2012 09:54:58 -0500 (CDT) Message-ID: <4FD606C1.1070103@hardwarefreak.com> Date: Mon, 11 Jun 2012 09:54:57 -0500 From: Stan Hoeppner MIME-Version: 1.0 Subject: Re: block sizes > 4K ?? possible w/large page support? References: <4FD5643F.5070801@tlinx.org> <20120611132932.GA18432@andromeda.usersys.redhat.com> In-Reply-To: <20120611132932.GA18432@andromeda.usersys.redhat.com> Reply-To: stan@hardwarefreak.com List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com On 6/11/2012 8:29 AM, Carlos Maiolino wrote: > The maximum block size of a XFS filesystem is 64kiB. But in linux it's limited > to the PAGE_SIZE value. Correct. > so, on x86 architectures, the maximum block size is > 4kiB. Not entirely correct. Since ~1996, 16 years ago, PPro and higher 32bit CPUs with PSE/PSE36 support pages of 4MB, or 2MB with PAE enabled. x86-64 CPUs in long mode also support a 2MB page size. But the problem of internal fragmentation may outweigh the TLB and other benefits of these very large pages. I'm not an MM dev so I can't elaborate further. There may be other issues. > although it could benefit from a 16kiB page size, you'll need to be running an > operating system which supports this page size value. And AFAIK the kernel MM team doesn't have x86 2MB pages on their radar. Or do they? -- Stan _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs