Re: [RFC][PATCH 6/6] automatic tuning applied to some kernel components

From: Nadia Derbey
Date: Thu Feb 15 2007 - 03:22:24 EST


Eric W. Biederman wrote:
Nadia Derbey <Nadia.Derbey@xxxxxxxx> writes:


But, what do you do with Oracle that's asking maxfiles to be set to 0x10000,
while the default value might be enough for a system that's not running Oracle.
I'm afraid that giving boot time values to the max_* tunables we will loose all
the benefits from /proc (or /sys): it is impossible to anticipate what an OS
will be used for. So allowing such things to be changed without having to reboot
the machine is in my mind quite a powerful feature we should keep taking
adavntage of.


I'm not saying remove user spaces' ability to set the
denial-of-service limits. I'm saying if they need to be frequently
changed we need to update the default so they are higher by default.

There really is no cost in moving those values up and down it is just
an arbitrary integer used in comparisons. But if we can make a good
guess that still catches runaway programs before they kill the machine
but also allows more programs to work out of the box we are in better
shape.

OK, happy to see we are on the same wavelength (and sorry for misunderstanding what you were saying ;-) )

Regards,
Nadia
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