Message-ID: <54645B38.10603@lge.com>
Date: Thu, 13 Nov 2014 16:18:16 +0900
From: Gioh Kim <gioh.kim@lge.com>
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To: Colin Cross <ccross@android.com>, Joonsoo Kim <js1304@gmail.com>
CC: John Stultz <john.stultz@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>, lauraa@codeaurora.org,
        devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
        =?EUC-KR?B?IsDMsMfIoy/DpcDTv6yxuL/4L1NXIFBs?=
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	<gunho.lee@lge.com>
Subject: Why does ion_cma_allocate need GFP_HIGHUSER | __GFP_ZERO flags?
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Hi,

I'm wondering why dma_alloc_coherent needs GFP_HIGHUSER | __GFP_ZERO flags in ion_cma_allocate().

I think dma_alloc_coherent can go to __dma_alloc if the system has CMA area.
If __GFP_WAIT flag is set, it allocates memory from atomic pool.
So I think calling dma_alloc_coherent with __GFP_WAIT is enough.

And can I get zero-filled-memory from CMA if I set __GFP_ZERO?


-- 
Thanks,
Gioh Kim
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