From: Vinod Koul <vinod.koul@intel.com>
To: Xiang Wang <wangxfdu@gmail.com>
Cc: Dan Williams <djbw@fb.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
cxie4@marvell.com, Xiang Wang <wangx@marvell.com>
Subject: Re: [PATCH v2] dma: mmp_pdma: fix a memory alloc error
Date: Mon, 29 Jul 2013 10:59:30 +0530 [thread overview]
Message-ID: <20130729052930.GC29095@intel.com> (raw)
In-Reply-To: <CACDNBm1jTTWLi3Prk+s_fk_BxNdzra4fG690sSMrKvwWXVW5oQ@mail.gmail.com>
On Thu, Jul 25, 2013 at 10:22:50AM +0800, Xiang Wang wrote:
Btw its generally a good idea to remove the parts not required for further
discussion
> Would you please explain a little more about why we should use
> GFP_NOWAIT here? This memory is not dedicated for DMA controller. Do
> we have special reasons to use GFP_NOWAIT? Thanks!
There are few reasons
- the dma requests can be triggered from atomic context
- so for above you can argue to use the GFP_ATOMIC and the guideline for dma
drivers [1] was discussed briefly
~Vinod
[1]: http://lkml.indiana.edu/hypermail/linux/kernel/0911.1/02316.html
--
next prev parent reply other threads:[~2013-07-29 6:08 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-18 6:21 [PATCH v2] dma: mmp_pdma: fix a memory alloc error Xiang Wang
2013-07-03 12:12 ` Xiang Wang
2013-07-05 6:45 ` Vinod Koul
2013-07-25 2:22 ` Xiang Wang
2013-07-29 5:29 ` Vinod Koul [this message]
2013-08-01 2:27 ` Xiang Wang
2013-08-19 9:17 ` Vinod Koul
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