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 PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 08 Sep 2010 21:32:42 +0800 From: Miao Xie <miaox@...fujitsu.com> To: Andi Kleen <andi@...stfloor.org> CC: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, Andrew Morton <akpm@...ux-foundation.org>, "Theodore Ts'o" <tytso@....edu>, Linux Kernel <linux-kernel@...r.kernel.org>, Linux Ext4 <linux-ext4@...r.kernel.org>, Linux Btrfs <linux-btrfs@...r.kernel.org> Subject: Re: [PATCH V2 1/3] lib: introduce some memory copy macros and functions On Wed, 8 Sep 2010 15:05:19 +0200, Andi Kleen wrote: > On Wed, 08 Sep 2010 20:57:07 +0800 > Miao Xie<miaox@...fujitsu.com> wrote: > >> On Wed, 8 Sep 2010 14:19:25 +0200 (cest), Andi Kleen wrote: >>> >>>> According to the data, the length of the most copies is>=128. >>> >>> Thanks for the data. Large is easier to optimize than small, that's >>> good. >>> >>> Could you also measure how many memsets need the backwards copy? ^^^^^^^ :-) >>> (should be easy to add) >> >> I think memset doesn't need the backwards copy. > > I meant for memmove of course. Obviously memset doesn't need a backwards > copy. That was just the only thing the script didn't measure because > the original version didn't have memmove support. memmove total 5224252 [snip] forward copy value |-------------------------------------------------- count 0 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 980253 backward copy value |-------------------------------------------------- count 0 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 4243999 the backward copy is much more than the forward copy. Thanks Miao -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists