linux-kernel - Re: [PATCH 4/4, v2] x86: enlightenment for ticket spin locks

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 for Android: free password hash cracker in your pocket

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

Date:	Wed, 30 Jun 2010 11:24:14 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Jan Beulich <JBeulich@...ell.com>
Cc:	jeremy.fitzhardinge@...rix.com, mingo@...e.hu, tglx@...utronix.de,
	Ky Srinivasan <KSrinivasan@...ell.com>,
	linux-kernel@...r.kernel.org, hpa@...or.com
Subject: Re: [PATCH 4/4, v2] x86: enlightenment for ticket spin locks -
 improve yield behavior on Xen

On Wed, 2010-06-30 at 09:49 +0100, Jan Beulich wrote:
> >>> On 30.06.10 at 10:11, Peter Zijlstra <peterz@...radead.org> wrote:
> > On Tue, 2010-06-29 at 15:35 +0100, Jan Beulich wrote:
> >> 
> >> The (only) additional overhead this introduces for native execution is
> >> the writing of the owning CPU in the lock acquire paths. 
> > 
> > Uhm, and growing the size of spinlock_t to 6 (or 8 bytes when aligned)
> > bytes when NR_CPUS>256.
> 
> Indeed, I should have mentioned that. Will do so in an eventual
> next version.

It would be good to also get a measure of data structure bloat caused by
this, not sure .data section size is representable there, but its
something easy to provide.

Something like: pahole -s build/vmlinux | awk '{t+=$2} END {print t}'
from before and after might also be interesting.
--
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/