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  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:	Sun, 08 Nov 2009 23:36:12 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	"Ma, Ling" <ling.ma@...el.com>
CC:	Ingo Molnar <mingo@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH RFC] [X86] performance improvement for memcpy_64.S by
 fast string.

On 11/08/2009 11:24 PM, Ma, Ling wrote:
> Hi All
> 
> Today we run our benchmark on Core2 and Sandy Bridge:
> 

Hi Ling,

Thanks for doing that.  Do you also have access to any older CPUs?  I
suspect that the CPUs that Andi are worried about are older CPUs like
P4, K8 or Pentium M/Core 1.  (Andi: please do clarify if you have
additional information.)

My personal opinion is that if we can show no significant slowdown on
P4, K8, P-M/Core 1, Core 2, and Nehalem then we can simply use this code
unconditionally.  If one of them is radically worse than baseline, then
we have to do something conditional, which is a lot more complicated.

[Ingo, Thomas: do you agree?]

Thanks,

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
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/

Powered by blists - more mailing lists