Re: [PATCH v2] slab,slub: ignore __GFP_WAIT if we're booting or suspending

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Sat, 2009-06-20 at 02:28 +0200, Pavel Machek wrote:
> 
> Academic for boot, probably real for suspend/resume. There the atomic
> reserves could matter because the memory can be pretty full when you
> start suspend.

Right, that might be something to look into, though we haven't yet
applied the technique for suspend & resume. My main issue with it at the
moment is how do I synchronize with allocations that are already
sleeping when changing the gfp flag mask without bloating the normal
path. I haven't had time to look into it, it's mostly a problem local to
the page allocator and reclaim, not much to do with SL*Bs though, which
is fortunate.

I also suspect that we might want to try to make -some- amount of free
space before starting suspend, though of course not nearly as
aggressively as with std.

Cheers,
Ben.