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    SubjectRe: [PATCH 0/5] make slab gfp fair
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    On Mon, 2007-05-14 at 09:29 -0700, Christoph Lameter wrote:
    > On Mon, 14 May 2007, Matt Mackall wrote:
    >
    > > privileged thread unprivileged greedy process
    > > kmem_cache_alloc(...)
    > > adds new slab page from lowmem pool
    >
    > Yes but it returns an object for the privileged thread. Is that not
    > enough?

    No, because we reserved memory for n objects, and like matt illustrates
    most of those that will be eaten by the greedy process.

    We could reserve 1 page per object but that rather bloats the reserve.

    > > do_io()
    > > kmem_cache_alloc(...)
    > > kmem_cache_alloc(...)
    > > kmem_cache_alloc(...)
    > > kmem_cache_alloc(...)
    > > kmem_cache_alloc(...)
    > > ...
    > > eats it all
    > > kmem_cache_alloc(...) -> ENOMEM
    > > who ate my donuts?!
    > >
    > > But I think this solution is somehow overkill. If we only care about
    > > this issue in the OOM avoidance case, then our rank reduces to a
    > > boolean.

    I tried to slim it down to a two state affair; but last time I tried
    performance runs that actually slowed it down some.

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