| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <87hcdsznep.fsf@basil.nowhere.org> Date: Wed, 23 Apr 2008 15:55:10 +0200 From: Andi Kleen <andi@...stfloor.org> To: Mel Gorman <mel@....ul.ie> Cc: wli@...omorphy.com, agl@...ibm.com, linux-mm@...ck.org, linux-kernel@...r.kernel.org Subject: Re: [RFC] Reserve huge pages for reliable MAP_PRIVATE hugetlbfs mappings Mel Gorman <mel@....ul.ie> writes: > MAP_SHARED mappings on hugetlbfs reserve huge pages at mmap() time. This is > so that all future faults will be guaranteed to succeed. Applications are not > expected to use mlock() as this can result in poor NUMA placement. > > MAP_PRIVATE mappings do not reserve pages. This can result in an application > being SIGKILLed later if a large page is not available at fault time. This > makes huge pages usage very ill-advised in some cases as the unexpected > application failure is intolerable. Forcing potential poor placement with > mlock() is not a great solution either. > > This patch reserves huge pages at mmap() time for MAP_PRIVATE mappings similar > to what happens for MAP_SHARED mappings. This will break all applications that mmap more hugetlbpages than they actually use. How do you know these don't exist? > Opinions? Seems like a risky interface change to me. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists