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    SubjectRe: [PATCH] pidmap: Use GFP_ATOMIC to allocate page (was: Re: [ 00/54] 3.0.32-stable review)
    On Sat, May 19, 2012 at 7:32 PM, David Rientjes <> wrote:
    > Why wasn't this caught by gfp_allowed_mask in slab_pre_alloc_hook()?
    > GFP_KERNEL should be allowed in this context.

    We set gfp_allowed_mask to allow all allocations before this point: it
    happens when we enable interrupts fairly early during start_kernel().

    So by the time pidmap_init() is called, GFP_KERNEL does imply that
    scheduling can happen.

    Which does imply that we set gfp_allowed_mask *much* too early. We
    still cannot schedule at that point (well, at least there's a comment
    saying so):

    * Disable preemption - early bootup scheduling is extremely
    * fragile until we cpu_idle() for the first time.

    so logically we should move the gfp_allowed_mask setting down to where
    we really are properly alive.

    How about moving it down to after we've done the full smp_init() and
    after we've actually done the first schedule and have proper idle

    Something like the attached (UNTESTED!) patch?

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      Last update: 2012-05-20 21:41    [W:0.025 / U:9.500 seconds]
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