Re: [Patch 1/1] init: Provide a kernel start parameter to increase pid_max v2

[Hedi Berriche <hedi@sgi.com>]

On Wed, Apr 21, 2010 at 20:52 Greg KH wrote:
| On Wed, Apr 21, 2010 at 08:12:13PM +0100, Hedi Berriche wrote:
| > Let's also not forget all those ephemeral user space tasks (udev and the likes)
| > that will be spawned at boot time on even large systems with even more
| > thousands of disks, arguably one might consider hack initrd and similar to work
| > around the problem and set pid_max as soon as /proc becomes available but it's
| > a bit of a PITA.
| 
| udev should properly handle large numbers of cpus and the tasks that it
| spawns so as to not overload things.  If not, and you feel it is
| creating too many tasks, please let the udev developers know and they
| will be glad to work with you on this issue.

Just to be clear here --and be done with the udev parenthesis-- we kind of need
udev to take advantage of the fact that there's a large number of CPUs on the
machine especially on in the case of a config with thousands of disks, as that
shortens the time required to have a box in a working state with all disks
available and all.

IOW, I am not after throttling or serialising udev, just mentioned it as an
example of user space beast that can contribute --in the current state of things--
to the need of having a large number of pid_max on certain configurations.

That said I do realise that bit too should be looked at and any problems, as you
quite rightly pointed out, should be discussed with the udev chaps.

Cheers,
Hedi.
-- 
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