Re: Mysterious slowdown in Chromium

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From	Gregor Kofler <usenet@gregorkofler.com>
Newsgroups	comp.lang.javascript
Subject	Re: Mysterious slowdown in Chromium
Date	Sun, 06 Jan 2013 16:25:59 +0100
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Am 2013-01-06 15:12, Stefan Weiss meinte:
> I was doing a quick benchmark in Chromium, when I noticed that
> subsequent runs were getting slower and slower. Reduced to the minimal
> case, the effect can be reproduced with this:
>
> <!DOCTYPE html>
> <html>
> <head>
>      <title>Test</title>
> </head>
> <body>
>      <script>
>      function bench() {
>          function test() {}
>          var runs = 10000000,  // adjust as needed
>              t0 = +new Date();
>          while (runs--) test();
>          console.log((+new Date() - t0) + "ms");
>      }
>      </script>
>      <button onclick="bench()">bench()</button>
> </body>
> </html>


Checked this on Chromium 22 (Ubuntu AMD64) in the web developer console

(function bench() {
   function test() {}
   var runs = 10000000,  // adjust as needed
   t0 = +new Date();
   while (runs--) test();
   console.log((+new Date() - t0) + "ms");
})();

Execution time stays constant with 90ms to 95ms.

Duplicating your test case I get

13ms
48ms
53ms
50ms
48ms
48ms
51ms
49ms
52ms
54ms
53ms
93ms
84ms
90ms
84ms
88ms
..
95ms (or less)

HTH, Gregor

Thread

Mysterious slowdown in Chromium Stefan Weiss <krewecherl@gmail.com> - 2013-01-06 15:12 +0100
  Re: Mysterious slowdown in Chromium GGolf <invalid@invalid.com> - 2013-01-06 20:22 +0530
  Re: Mysterious slowdown in Chromium Gregor Kofler <usenet@gregorkofler.com> - 2013-01-06 16:25 +0100
    Re: Mysterious slowdown in Chromium Stefan Weiss <krewecherl@gmail.com> - 2013-01-06 17:33 +0100
      Re: Mysterious slowdown in Chromium Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-01-06 23:44 +0100
  Re: Mysterious slowdown in Chromium Scott Sauyet <scott.sauyet@gmail.com> - 2013-01-06 08:19 -0800
  Re: Mysterious slowdown in Chromium Patricia Shanahan <pats@acm.org> - 2013-01-06 08:32 -0800

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