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    SubjectRe: [PATCH] get rid of NR_OPEN and introduce a sysctl_nr_open
    On Tue, 27 Nov 2007 08:09:19 +0100, Eric Dumazet said:

    > Changing NR_OPEN is not considered safe because of vmalloc space potential
    > exhaust.

    Verbiage about this point...

    > +nr_open
    > +-------
    > +
    > +Denotes the maximum number of file-handles a process can
    > +allocate. Default value is 1024*1024 (1048576) which should be
    > +enough for most machines. Actual limit depends on RLIMIT_NOFILE
    > +resource limit.
    > +

    should probably be in here - can you add something of the form "Setting this
    too high can cause vmalloc failures, especially on smaller-RAM machines",
    and/or *say* how much RAM the default takes? Sure, it's 1M entries, but
    my tuning on a 2G-RAM machine will differ if these are byte-sized, or 128-byte
    sized - one is off in a corner, the other is 1/16th of my entire memory.

    Also, would it be useful to *lower* the value drastically, if you know a priori
    that no process should get up to 1K file handles, much less 1M? Does that
    buy me anything different than setting RLIMIT_NOFILE=1024?
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      Last update: 2007-11-27 08:31    [W:0.044 / U:35.560 seconds]
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