From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from thermo.lanl.gov (thermo.lanl.gov [128.165.59.202]) by mailwasher-b.lanl.gov (8.12.11/8.12.11/(ccn-5)) with SMTP id jA70Yv7d021298 for ; Sun, 6 Nov 2005 17:34:58 -0700 Subject: RE: [Lhms-devel] [PATCH 0/7] Fragmentation Avoidance V19 In-Reply-To: <01EF044AAEE12F4BAAD955CB75064943051354C4@scsmsx401.amr.corp.intel.com> Message-Id: <20051107003452.3A0B41855A0@thermo.lanl.gov> Date: Sun, 6 Nov 2005 17:34:52 -0700 (MST) From: andy@thermo.lanl.gov (Andy Nelson) Sender: owner-linux-mm@kvack.org Return-Path: To: ak@suse.de, nickpiggin@yahoo.com.au, rohit.seth@intel.com Cc: akpm@osdl.org, andy@thermo.lanl.gov, arjan@infradead.org, arjanv@infradead.org, gmaxwell@gmail.com, haveblue@us.ibm.com, kravetz@us.ibm.com, lhms-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mbligh@mbligh.org, mel@csn.ul.ie, mingo@elte.hu, torvalds@osdl.org List-ID: Hi folks, >Not sure how applications seamlessly can use the proposed hugetlb zone >based on hugetlbfs. Depending on the programming language, it might >actually need changes in libs/tools etc. This is my biggest worry as well. I can't recall the details right now, but I have some memories of people telling me, for example, that large pages on linux were not now available to fortran programs period, due to lack of toolchain/lib stuff, just as you note. What the reasons were/are I have no idea. I do know that the Power 5 numbers I quoted a couple of days ago required that the sysadmin apply some special patches to linux and linking to extra library. I don't know what patches (they came from ibm), but for xlf95 on Power5, the library I had to link with was this one: -T /usr/local/lib64/elf64ppc.lbss.x No changes were required to my code, which is what I need, but codes that did not link to this library would not run on a kernel that had the patches installed, and code that did link with this library would not run on a kernel that didn't have those patches. I don't know what library this is or what was in it, but I cant imagine it would have been something very standard or mainline, with that sort of drastic behavior. Maybe the ibm folk can explain what this was about. I will ask some folks here who should know how it may work on intel/amd machines about how large pages can be used this coming week, when I attempt to do page size speed testing for my code, as I promised before, as I promised before, as I promised before. Andy -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org