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Date: Sun, 16 Nov 2008 23:13:01 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com>
Cc: "KAMEZAWA Hiroyuki" <kamezawa.hiroyu@jp.fujitsu.com>,
       balbir@linux.vnet.ibm.com, "Lai Jiangshan" <laijs@cn.fujitsu.com>,
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       linux-kernel@vger.kernel.org, dada1@cosmosbay.com,
       "Alexey Dobriyan" <adobriyan@gmail.com>
Subject: Re: [PATCH 1/7] mm: introduce simple_malloc()/simple_free()
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On Mon, 17 Nov 2008 15:43:59 +0900 "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com> wrote:

> >> > (I'll rename simple_malloc/simple_free to kvmalloc/kvfree)
> >> >
> >>
> >> I would prefer to find a way to say that one cannot select gfp_mask with this API.
> >>
> > I think gfp_mask must be passed explicitly.
> 
> Agreed.

It would only make sense if __vmalloc() can be called in atomic contexts.

__vmalloc() cannot be called from irq contexts due to it taking
non-irq-safe spinlocks.

__vmalloc() kinda looks like it could be called from non-irq atomic
contexts with GFP_ATOMIC, but I think it lies.  For example,
pud_alloc_one/pmd_alloc_one/etc use hard-wired GFP_KERNEL.

In which case this new allocation function can only be called from
contexts where GFP_KERNEL can be used, hence we don't need to pass that
in - it would be misleading to do so.

In fact it's not immediately clear why __vmalloc() takes a gfp_t
argument either?