Re: [PATCH] make vm_enough_memory more efficient

Martin J. Bligh (mbligh@aracnet.com)
Thu, 16 Jan 2003 07:22:33 -0800


>> vm_enough_memory seems to call si_meminfo just to get the total
>> RAM, which seems far too expensive. This replaces the comment
>> saying "this is crap" with some code that's less crap.
>>
>> Not heavily tested (compiles and boots), but seems pretty obvious.
>
> Yup, obviously correct.

Cool.

> The really hurtful part of vm_enough_memory() is the call to
> get_page_cache_size(), which has to go over every CPU's local VM statistics
> in get_page_state().
>
> But I guess you're running with sysctl_overcommit_memory != 0.

Yup, I manually disable that because it's so expensive. I'll see if
I can make the default case cheaper as well.

M.

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