Re: [RFC PATCH] sparse_irq aka dyn_irq

From: Ingo Molnar
Date: Mon Nov 10 2008 - 05:10:29 EST



* Yinghai Lu <yinghai@xxxxxxxxxx> wrote:

> Ingo Molnar wrote:
> > * Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> >
> >> Andrew Morton wrote:
> >>> On Mon, 10 Nov 2008 10:40:33 +0100 Ingo Molnar <mingo@xxxxxxx> wrote:
> >>>
> >>>>>>> @@ -987,6 +988,8 @@ void __init mem_init(void)
> >>>>>>>
> >>>>>>> set_highmem_pages_init();
> >>>>>>>
> >>>>>>> + after_bootmem = 1;
> >>>>>> this hack can go away once we have a proper percpu_alloc() that can be
> >>>>>> used early enough.
> >>>>> where is that fancy patch? current percpu_alloc(), will keep big
> >>>>> pointer in array..., instead of put that pointer in percpu_area
> >>>>>
> >>>>> 64bit has that after_bootmem already.
> >>>> or at least introduce a "bootmem agnostic" allocator instead of
> >>>> open-coding the after_bootmem flag.
> >>>>
> >>>> Something like:
> >>>>
> >>>> early_kzalloc()
> >>>>
> >>>> ?
> >>>>
> >>>> Andrew, any preferences?
> >>> My mind reading ain't what it was, and this after_bootmem flag is
> >>> write-only in this patch.
> >>>
> >>> So what's all this about?
> >> if i use alloc_bootmem to get some memory, and later after_bootmem,
> >> can I use kfree to free it?
> >
> > hm, no. If we used alloc_bootmem(), then we must not free it after
> > after_bootmem has been set.
>
> ok, let keep irq_desc for legacy irqs not movable...

most of them are movable right now, correct? If we restrict their
movability now that might surprise existing usecases negatively.

Ingo
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