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    SubjectRE: [patch 0/3] no MAX_ARG_PAGES -v2
    > This patch-set aims at removing the current limit on argv+env space aka.

    Running with this patch shows that /bin/bash has some unpleasant
    O(n^2) performance issues with long argument lists. I made a
    1Mbyte file full of pathnames, then timed the execution of:

    $ /bin/echo `cat megabyte` | wc
    $ /bin/echo `cat megabyte megabyte` | wc
    etc. ...

    System time was pretty much linear as the arglist grew
    (and only got up to 0.144 seconds at 5Mbytes).

    But user time ~= real time (in seconds) looks like:

    1 5.318
    2 18.871
    3 40.620
    4 70.819
    5 108.911

    Above 5Mbytes, I started seeing problems. The line/word/char
    counts from "wc" started being "0 0 0". Not sure if this is
    a problem in "wc" dealing with a single line >5MBytes, or some
    other problem (possibly I was exceeding the per-process stack
    limit which is only 8MB on that machine).

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      Last update: 2007-06-14 01:39    [W:0.020 / U:46.116 seconds]
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