linux-kernel - Re: [RFT] Please test rdtsc on various x86-64 hardware (app included)

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: <BANLkTi=hpNy3iA+49N90dbU4f0_L2RVJNQ@mail.gmail.com>
Date:	Mon, 18 Apr 2011 13:16:11 -0700
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Andrew Lutomirski <luto@....edu>
Cc:	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>,
	Andi Kleen <andi@...stfloor.org>, x86 <x86@...nel.org>
Subject: Re: [RFT] Please test rdtsc on various x86-64 hardware (app included)

On Mon, Apr 18, 2011 at 12:32 PM, Andrew Lutomirski <luto@....edu> wrote:
>
> I've tested on Sandy Bridge, Allendale (i.e. Pentium Dual-Core),
> Bloomfield. and C2D.

Arrandale:

  CPU vendor   : GenuineIntel
  CPU model    : Intel(R) Core(TM) i5 CPU         670  @ 3.47GHz
  CPU stepping : 2
  TSC flags    : tsc rdtscp constant_tsc nonstop_tsc
  Using lfence_rdtsc because you have an Intel CPU
  Will test the "lfence;rdtsc" clock.
  Now test passed  : margin 98 with 71696816 samples
  Load3 test passed: margin 72 with 8926478 samples
  Load test passed : margin 88 with 14660759 samples
  Store test failed as expected: worst error 764 with 10784245 samples

but that wasn't very surprising since you already tested the
micro-architectures just around it.

On a dual-socket X5550 (master.kernel.org: 16 threads total: 4 cores
per socket, with HT):

  CPU vendor   : GenuineIntel
  CPU model    : Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
  CPU stepping : 5
  TSC flags    : tsc rdtscp constant_tsc nonstop_tsc
  Using lfence_rdtsc because you have an Intel CPU
  Will test the "lfence;rdtsc" clock.
  Now test passed  : margin 166 with 38875272 samples
  Load3 test passed: margin 235 with 2972261 samples
  Load test passed : margin 119 with 4409699 samples
  Store test failed as expected: worst error 2710 with 3764216 samples

Some opteron love would be good, but I don't have access to any right here.

                     Linus
--
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/