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
| ||
|
Date: Sat, 28 Mar 2009 09:46:57 +0100 From: Brice Goglin <Brice.Goglin@...ia.fr> To: Peter Zijlstra <peterz@...radead.org> CC: Eric Anholt <eric@...olt.net>, Andi Kleen <andi@...stfloor.org>, linux-kernel@...r.kernel.org, dri-devel@...ts.sourceforge.net, Nick Piggin <nickpiggin@...oo.com.au> Subject: Re: DRM lock ordering fix series Peter Zijlstra wrote: > Also note that doing large gup() with gup_fast() will be undesirable due > to it disabling IRQs. So iterating say several MB worth of pages will > hurt like crazy. Currently all gup_fast() users do a single page lookup. > In 2.6.29, fs/bio.c:955, fs/direct-io.c:153 and fs/splice.c:1222 do multiple-pages lookup at once. The latter might be limited to 16 pages because of the pipe-depth, I don't know about the formers. Is there some sort of reasonable limit? A couple dozens pages at once maybe? Brice -- 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