linux-kernel - Re: [PATCH 0/2] Add percpu smp cacheline align section

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 5 May 2007 09:52:27 -0700 (PDT)
From:	Christoph Lameter <clameter@....com>
To:	Fenghua Yu <fenghua.yu@...el.com>
cc:	akpm@...ux-foundation.org, suresh.b.siddha@...el.com,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/2] Add percpu smp cacheline align section

On Fri, 4 May 2007, Fenghua Yu wrote:

> This is follow-up for Suresh's runqueue align in smp patch at:
> http://www.uwsg.iu.edu/hypermail/linux/kernel/0704.1/0340.html
> 
> The patches place all of smp cacheline aligned percpu data into 
> .data.percpu.cacheline_aligned_in_smp. Other percpu data is still in 
> data.percpu section. The patches can reduce cache line access in SMP and 
> reduce alignment gap waste. The patches also define PERCPU macro for 
> vmlinux.lds.S for code clean up.

Ummm... The per cpu area is for exclusive use of a particular processor. 
If there is contention in the per cpu area then a data object needs to be 
removed from the per cpu area because the object is *not* accessed only 
from a certain cpu.

-
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/