From: Paul Cercueil <paul@crapouillou.net>
To: Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>
Cc: Paul Cercueil <paul@crapouillou.net>,
iommu@lists.linux-foundation.org, od@zcrc.me,
linux-kernel@vger.kernel.org
Subject: [PATCH] cma: decrease CMA_ALIGNMENT lower limit to 2
Date: Wed, 30 Sep 2020 12:28:21 +0200 [thread overview]
Message-ID: <20200930102821.26421-1-paul@crapouillou.net> (raw)
On an embedded system with a tiny (1 MiB) CMA area for video memory, and
a simple enough video pipeline, we can decrease the CMA_ALIGNMENT by a
factor of 2 to avoid wasting memory, as all the allocations for video
buffers will be of the exact same size (dictated by the size of the
screen).
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
kernel/dma/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 847a9d1fa634..f15e782e19ca 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -162,7 +162,7 @@ endchoice
config CMA_ALIGNMENT
int "Maximum PAGE_SIZE order of alignment for contiguous buffers"
- range 4 12
+ range 2 12
default 8
help
DMA mapping framework by default aligns all buffers to the smallest
--
2.28.0
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next reply other threads:[~2020-10-01 0:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-30 10:28 Paul Cercueil [this message]
2020-10-05 13:04 ` [PATCH] cma: decrease CMA_ALIGNMENT lower limit to 2 Christoph Hellwig
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