Re: [RFC] propagate gfp_t to page table alloc functions

[KAMEZAWA Hiroyuki]

(2012/04/25 6:30), Andrew Morton wrote:

> On Tue, 24 Apr 2012 17:48:29 +1000
> Nick Piggin <npiggin@xxxxxxxxx> wrote:
> 
>>> Hmm, there are several places to use GFP_NOIO and GFP_NOFS even, GFP_ATOMIC.
>>> I believe it's not trivial now.
>>
>> They're all buggy then. Unfortunately not through any real fault of their own.
> 
> There are gruesome problems in block/blk-throttle.c (thread "mempool,
> percpu, blkcg: fix percpu stat allocation and remove stats_lock").  It
> wants to do an alloc_percpu()->vmalloc() from the IO submission path,
> under GFP_NOIO.
> 
> Changing vmalloc() to take a gfp_t does make lots of sense, although I
> worry a bit about making vmalloc() easier to use!
> 
> I do wonder whether the whole scheme of explicitly passing a gfp_t was
> a mistake and that the allocation context should be part of the task
> context.  ie: pass the allocation mode via *current.  


yes...that's very interesting. 

Regards,
-Kame

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/