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Re: time stamp counter in "make check"

From: Roland McGrath <roland at hack dot frob dot com>
To: Dmitrieva Liubov <liubov dot dmitrieva at gmail dot com>
Cc: libc-alpha at sourceware dot org
Date: Wed, 25 Jul 2012 11:24:20 -0700 (PDT)
Subject: Re: time stamp counter in "make check"
References: <CAHjhQ93k9cAv9=hh8W0BbBsR6Gf6fFC4498j21ksfrjcFCME4w@mail.gmail.com>

Using rdtsc or the like for user-mode CPU timings is always wrong.
Even if the CPU issues are handled perfectly, it's only ever right
when the luck of the draw doesn't introduce any scheduling delays
in the middle of what you're timing.

Follow-Ups:
- Re: time stamp counter in "make check"
  - From: OndÅej BÃlka

References:
- time stamp counter in "make check"
  - From: Dmitrieva Liubov

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