On 21/11/2018 16:07, Will Deacon wrote:
On Wed, Nov 21, 2018 at 10:54:10PM +0800, John Garry wrote:
From: Ganapatrao Kulkarni <[email protected]>
Change function __iommu_dma_alloc_pages() to allocate pages for DMA from
respective device NUMA node. The ternary operator which would be for
alloc_pages_node() is tidied along with this.
We also include a change to use kvzalloc() for kzalloc()/vzalloc()
combination.
Signed-off-by: Ganapatrao Kulkarni <[email protected]>
[JPG: Added kvzalloc(), drop pages ** being device local, tidied ternary
operator]
Signed-off-by: John Garry <[email protected]>
Weird, you're missing a diffstat here.
Anyway, the patch looks fine to me, but it would be nice if you could
justify the change with some numbers. Do you actually see an improvement
from this change?
Hi Will,
Ah, I missed adding my comments explaining the motivation. It would be
better in the commit log. Anyway, here's the snippet:
" ... as mentioned in [3], dma_alloc_coherent() uses the locality
information from the device - as in direct DMA - so this patch is just
applying this same policy.
[3]
https://www.mail-archive.com/[email protected]/msg1692998.html";
I did have some numbers to show improvement in some scenarios when I
tested this a while back which I'll dig out.
However I would say that some scenarios will improve and the opposite
for others with this change, considering different conditions in which
DMA memory may be used.
Cheers,
John
Will
.
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