linux-kernel - Re: [PATCH] configure HAVE_UNSTABLE_SCHED_CLOCK for SGI

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:	Wed, 7 Jan 2009 07:32:30 -0600
From:	Dimitri Sivanich <sivanich@....com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Robin Holt <holt@....com>, Nick Piggin <npiggin@...e.de>,
	"Luck, Tony" <tony.luck@...el.com>,
	"linux-ia64@...r.kernel.org" <linux-ia64@...r.kernel.org>,
	Greg KH <greg@...ah.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Gregory Haskins <ghaskins@...ell.com>,
	Tony Luck <tony.luck@...il.com>
Subject: Re: [PATCH] configure HAVE_UNSTABLE_SCHED_CLOCK for SGI_SN systems

Peter,

On Wed, Jan 07, 2009 at 10:53:57AM +0100, Peter Zijlstra wrote:
> 
> Clock state is kept per-cpu, and locked with a spinlock. When we request

Admittedly I have not looked at this possibility too closely, but my initial concern upon looking at sched_clock_cpu() for the UNSTABLE case was the lock_double_clock() and what sort of contention that might cause on larger systems under certain conditions.
--
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/