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 for Android: free password hash cracker in your pocket

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

Message-ID: <4977A051.8050203@goop.org>
Date:	Wed, 21 Jan 2009 14:23:13 -0800
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Nick Piggin <npiggin@...e.de>
CC:	Ingo Molnar <mingo@...e.hu>,
	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>,
	Xen-devel <xen-devel@...ts.xensource.com>
Subject: Re: lmbench lat_mmap slowdown with CONFIG_PARAVIRT

Nick Piggin wrote:
> Oh, _llc_ references/misses? Ouch.
>
> You have, what 32K L1I, 32K L1D, and 4MB L2? And even this microbenchmark
> is seeing increased L2 misses by nearly 3%. Hmm, I wonder where that is
> coming from? Instruction fetches?
>   

I assume so.  There should be no extra data accesses with 
CONFIG_PARAVIRT (hm, there's probably some extra stack/spill traffic, 
but I surely hope that's not falling out of cache).

    J
--
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/