Groups > linux.kernel > #1206984

Re: get_vmalloc_info() and /proc/meminfo insanely expensive

From	Linus Torvalds <torvalds@linux-foundation.org>
Newsgroups	linux.kernel
Subject	Re: get_vmalloc_info() and /proc/meminfo insanely expensive
Date	2015-08-13 19:00 +0200
Message-ID	<pX41d-Hx-53@gated-at.bofh.it> (permalink)
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On Thu, Aug 13, 2015 at 12:42 AM, Rasmus Villemoes
<linux@rasmusvillemoes.dk> wrote:
>
> I think it's simpler and better to fix glibc.

Well, I certainly don't disagree, but at the same time I suspect that
(a) many distros will not update glibc very aggressively and (b) we
should fix the unnecessarily expensive kernel operation regardless.

I think that just printing out the ASCII numbers in /proc/meminfo
should be a lot more expensive than computing the numbers. Which is
clearly not the case now, because we do that crazy expensive dynamic
computation every time, even though it hardly ever really changes (and
nobody even really cares about the values).

So I'd prefer to fix the kernel for existing insane users (because the
kernel is just doing stupid things that it didn't expect anybody to
care about), _and_ fix glibc.

                     Linus
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Thread

get_vmalloc_info() and /proc/meminfo insanely expensive Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 05:30 +0200
  Re: get_vmalloc_info() and /proc/meminfo insanely expensive Andrew Morton <akpm@linux-foundation.org> - 2015-08-13 06:10 +0200
    Re: get_vmalloc_info() and /proc/meminfo insanely expensive Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 08:00 +0200
      Re: get_vmalloc_info() and /proc/meminfo insanely expensive Rasmus Villemoes <linux@rasmusvillemoes.dk> - 2015-08-13 09:50 +0200
        Re: get_vmalloc_info() and /proc/meminfo insanely expensive Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 19:00 +0200
      Re: get_vmalloc_info() and /proc/meminfo insanely expensive Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 20:40 +0200
        Re: get_vmalloc_info() and /proc/meminfo insanely expensive Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 21:00 +0200
          Re: get_vmalloc_info() and /proc/meminfo insanely expensive David Rientjes <rientjes@google.com> - 2015-08-13 22:00 +0200
            Re: get_vmalloc_info() and /proc/meminfo insanely expensive Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 22:10 +0200
        Re: get_vmalloc_info() and /proc/meminfo insanely expensive Tony Luck <tony.luck@gmail.com> - 2015-08-13 23:30 +0200
          Re: get_vmalloc_info() and /proc/meminfo insanely expensive Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 01:00 +0200
      Re: get_vmalloc_info() and /proc/meminfo insanely expensive Andrew Morton <akpm@linux-foundation.org> - 2015-08-13 22:30 +0200

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