linux-kernel - Re: lmbench lat_mmap slowdown with CONFIG

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]

Message-ID: <20090120151347.GA4309@elte.hu>
Date:	Tue, 20 Jan 2009 16:13:47 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Nick Piggin <npiggin@...e.de>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>, hpa@...or.com,
	jeremy@...source.com, chrisw@...s-sol.org, zach@...are.com,
	rusty@...tcorp.com.au, Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: lmbench lat_mmap slowdown with CONFIG_PARAVIRT


* Ingo Molnar <mingo@...e.hu> wrote:

> That shows the expected $cache risks here as well: i ran this on an 
> Extreme Edition CPU which has a ton of L2 cache [4MB] which mutes L2 
> $cache misses quite a bit.

[ there's no such thing as "L2 $cache misses" - what i wanted to say is 
  that while the instruction cache size is rather small and static, a
  large L2 cache helps in keeping the costs of instruction-cache misses
  low - hence my measurement skews in favor of paravirt. ]

	Ingo
--
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/