Re: [PATCH 0/5] make slab gfp fair

Paul Jackson
2007-05-17T21:44:36Z

> The way I read the cpuset page allocator, it will only respect the
> cpuset if there is memory aplenty. Otherwise it will grab whatever. So
> still, it will only ever use ALLOC_NO_WATERMARKS if the whole system is
> in distress.

Wrong. Well, only a little right.

For allocations that can't fail (the kernel could die if it failed)
then yes, the kernel will eventually take any damn page it can find,
regardless of cpusets.

Allocations for user space are hardwall enforced to be in the current
tasks cpuset.

Allocations off interrupts ignore the current tasks cpuset (such allocations
don't have a valid current contect.)

Allocations for most kernel space allocations will try to fit in the
current tasks cpuset, but may come from the possibly larger context of
the closest ancestor cpuset that is marked memory_exclusive.

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@sgi.com> 1.925.600.0401