On 10/11/2020 08:10, Song Bao Hua (Barry Song) wrote:
Hello Robin, Christoph,
Any further comment? John suggested that "depends on DEBUG_FS" should be added
in Kconfig.
I am collecting more comments to send v4 together with fixing this minor issue
:-)
Thanks
Barry
-----Original Message-----
From: Song Bao Hua (Barry Song)
Sent: Monday, November 2, 2020 9:07 PM
To: [email protected]; [email protected]; [email protected];
[email protected]
Cc: Linuxarm <[email protected]>; [email protected]; xuwei
(O) <[email protected]>; Song Bao Hua (Barry Song)
<[email protected]>; Joerg Roedel <[email protected]>; Will Deacon
<[email protected]>; Shuah Khan <[email protected]>
Subject: [PATCH v3 1/2] dma-mapping: add benchmark support for streaming
DMA APIs
Nowadays, there are increasing requirements to benchmark the performance
of dma_map and dma_unmap particually while the device is attached to an
IOMMU.
This patch enables the support. Users can run specified number of threads to
do dma_map_page and dma_unmap_page on a specific NUMA node with the
specified duration. Then dma_map_benchmark will calculate the average
latency for map and unmap.
A difficulity for this benchmark is that dma_map/unmap APIs must run on a
particular device. Each device might have different backend of IOMMU or
non-IOMMU.
So we use the driver_override to bind dma_map_benchmark to a particual
device by:
For platform devices:
echo dma_map_benchmark > /sys/bus/platform/devices/xxx/driver_override
echo xxx > /sys/bus/platform/drivers/xxx/unbind
echo xxx > /sys/bus/platform/drivers/dma_map_benchmark/bind
Hi Barry,
For PCI devices:
echo dma_map_benchmark >
/sys/bus/pci/devices/0000:00:01.0/driver_override
echo 0000:00:01.0 > /sys/bus/pci/drivers/xxx/unbind echo 0000:00:01.0 >
/sys/bus/pci/drivers/dma_map_benchmark/bind
Do we need to check if the device to which we attach actually has DMA
mapping capability?
Cc: Joerg Roedel <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Robin Murphy <[email protected]>
Signed-off-by: Barry Song <[email protected]>
---
Thanks,
John
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