Messages in this thread | | | Subject | Re: [PATCH] get rid of NR_OPEN and introduce a sysctl_nr_open | From | Valdis.Kletnieks@vt ... | Date | Tue, 27 Nov 2007 02:25:56 -0500 |
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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? [unhandled content-type:application/pgp-signature] | |