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

Christoph Lameter
2007-05-14T16:37:49Z

On Mon, 14 May 2007, Peter Zijlstra wrote:

> > Why does this have to handled by the slab allocators at all? If you have
> > free pages in the page allocator then the slab allocators will be able to
> > use that reserve.
>
> Yes, too freely. GFP flags are only ever checked when you allocate a new
> page. Hence, if you have a low reaching alloc allocating a slab page;
> subsequent non critical GFP_KERNEL allocs can fill up that slab. Hence
> you would need to reserve a slab per object instead of the normal
> packing.

This is all about making one thread fail rather than another? Note that
the allocations are a rather compex affair in the slab allocators. Per
node and per cpu structures play a big role.