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From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni)
To: kernelnewbies@lists.kernelnewbies.org
Subject: CMA question
Date: Tue, 28 Feb 2017 11:04:42 +0100	[thread overview]
Message-ID: <20170228110442.379dfc66@free-electrons.com> (raw)
In-Reply-To: <8f4cc452-c25d-64ca-3806-816c819f683c@johannesthoma.com>

Hello,

On Sun, 26 Feb 2017 18:14:42 +0100, Johannes Thoma wrote:

> As you pointed out the solution would be to allocate the memory earlier in the
> boot process, by modifying the driver. I will try that in the next few days and
> let you know the result.

The whole point of CMA is that allocating earlier in the boot process
should not be necessary. CMA guarantees that the memory reserved for
the CMA pool is "movable", i.e it can be discarded when a CMA
allocation is done.

So if a CMA allocation fails, I would rather suggest that the size of
your CMA pool is not large enough. Check your Device Tree and/or kernel
command (you can specify the size of the CMA pool on both if I remember
correctly).

Best regarsd,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

  reply	other threads:[~2017-02-28 10:04 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-26 16:29 CMA question Johannes Thoma
2017-02-26 16:31 ` Greg KH
2017-02-26 17:14   ` Johannes Thoma
2017-02-28 10:04     ` Thomas Petazzoni [this message]
2017-02-28 17:48       ` Johannes Thoma

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