Re: [PATCH 0/8] dmaengine: Add new API to combine onfiguration and descriptor preparation

Niklas Cassel
2025-12-09T07:20:09Z

On Mon, Dec 08, 2025 at 12:09:39PM -0500, Frank Li wrote:
> Frank Li (8):
> dmaengine: Add API to combine configuration and preparation (sg and single)
> PCI: endpoint: pci-epf-test: use new DMA API to simple code
> dmaengine: dw-edma: Use new .device_prep_slave_sg_config() callback
> dmaengine: dw-edma: Pass dma_slave_config to dw_edma_device_transfer()
> nvmet: pci-epf: Remove unnecessary dmaengine_terminate_sync() on each DMA transfer
> nvmet: pci-epf: Use dmaengine_prep_slave_single_config() API
> PCI: epf-mhi:Using new API dmaengine_prep_slave_single_config() to simple code.
> crypto: atmel: Use dmaengine_prep_slave_single_config() API
>
> drivers/crypto/atmel-aes.c | 10 ++---
> drivers/dma/dw-edma/dw-edma-core.c | 38 +++++++++++-----
> drivers/nvme/target/pci-epf.c | 21 +++------
> drivers/pci/endpoint/functions/pci-epf-mhi.c | 52 +++++++---------------
> drivers/pci/endpoint/functions/pci-epf-test.c | 8 +---
> include/linux/dmaengine.h | 64 ++++++++++++++++++++++++---
> 6 files changed, 111 insertions(+), 82 deletions(-)
> ---
> base-commit: bc04acf4aeca588496124a6cf54bfce3db327039
> change-id: 20251204-dma_prep_config-654170d245a2

For the series (tested using drivers/nvme/target/pci-epf.c):
Tested-by: Niklas Cassel <cassel@kernel.org>

Mainline:
Rnd read, 4KB, QD=1, 1 job : IOPS=5721, BW=22.3MiB/s (23.4MB/s)
Rnd read, 4KB, QD=32, 1 job : IOPS=51.8k, BW=202MiB/s (212MB/s)
Rnd read, 4KB, QD=32, 4 jobs: IOPS=109k, BW=426MiB/s (447MB/s)
Rnd read, 128KB, QD=1, 1 job : IOPS=2678, BW=335MiB/s (351MB/s)
Rnd read, 128KB, QD=32, 1 job : IOPS=19.1k, BW=2388MiB/s (2504MB/s)
Rnd read, 128KB, QD=32, 4 jobs: IOPS=18.1k, BW=2258MiB/s (2368MB/s)
Rnd read, 512KB, QD=1, 1 job : IOPS=1388, BW=694MiB/s (728MB/s)
Rnd read, 512KB, QD=32, 1 job : IOPS=4554, BW=2277MiB/s (2388MB/s)
Rnd read, 512KB, QD=32, 4 jobs: IOPS=4516, BW=2258MiB/s (2368MB/s)
Rnd write, 4KB, QD=1, 1 job : IOPS=4679, BW=18.3MiB/s (19.2MB/s)
Rnd write, 4KB, QD=32, 1 job : IOPS=35.1k, BW=137MiB/s (144MB/s)
Rnd write, 4KB, QD=32, 4 jobs: IOPS=33.7k, BW=132MiB/s (138MB/s)
Rnd write, 128KB, QD=1, 1 job : IOPS=2490, BW=311MiB/s (326MB/s)
Rnd write, 128KB, QD=32, 1 job : IOPS=4964, BW=621MiB/s (651MB/s)
Rnd write, 128KB, QD=32, 4 jobs: IOPS=4966, BW=621MiB/s (651MB/s)
Seq read, 128KB, QD=1, 1 job : IOPS=2586, BW=323MiB/s (339MB/s)
Seq read, 128KB, QD=32, 1 job : IOPS=17.5k, BW=2190MiB/s (2296MB/s)
Seq read, 512KB, QD=1, 1 job : IOPS=1614, BW=807MiB/s (847MB/s)
Seq read, 512KB, QD=32, 1 job : IOPS=4540, BW=2270MiB/s (2381MB/s)
Seq read, 1MB, QD=32, 1 job : IOPS=2283, BW=2284MiB/s (2395MB/s)
Seq write, 128KB, QD=1, 1 job : IOPS=2313, BW=289MiB/s (303MB/s)
Seq write, 128KB, QD=32, 1 job : IOPS=4948, BW=619MiB/s (649MB/s)
Seq write, 512KB, QD=1, 1 job : IOPS=901, BW=451MiB/s (473MB/s)
Seq write, 512KB, QD=32, 1 job : IOPS=1289, BW=645MiB/s (676MB/s)
Seq write, 1MB, QD=32, 1 job : IOPS=632, BW=633MiB/s (663MB/s)
Rnd rdwr, 4K..1MB, QD=8, 4 jobs: IOPS=1756, BW=880MiB/s (923MB/s)
IOPS=1767, BW=886MiB/s (929MB/s)

Mainline + this series applied:
Rnd read, 4KB, QD=1, 1 job : IOPS=3681, BW=14.4MiB/s (15.1MB/s)
Rnd read, 4KB, QD=32, 1 job : IOPS=54.8k, BW=214MiB/s (224MB/s)
Rnd read, 4KB, QD=32, 4 jobs: IOPS=123k, BW=479MiB/s (502MB/s)
Rnd read, 128KB, QD=1, 1 job : IOPS=2132, BW=267MiB/s (280MB/s)
Rnd read, 128KB, QD=32, 1 job : IOPS=19.0k, BW=2369MiB/s (2485MB/s)
Rnd read, 128KB, QD=32, 4 jobs: IOPS=18.7k, BW=2341MiB/s (2454MB/s)
Rnd read, 512KB, QD=1, 1 job : IOPS=1135, BW=568MiB/s (595MB/s)
Rnd read, 512KB, QD=32, 1 job : IOPS=4546, BW=2273MiB/s (2384MB/s)
Rnd read, 512KB, QD=32, 4 jobs: IOPS=4708, BW=2354MiB/s (2469MB/s)
Rnd write, 4KB, QD=1, 1 job : IOPS=3369, BW=13.2MiB/s (13.8MB/s)
Rnd write, 4KB, QD=32, 1 job : IOPS=31.7k, BW=124MiB/s (130MB/s)
Rnd write, 4KB, QD=32, 4 jobs: IOPS=31.1k, BW=122MiB/s (127MB/s)
Rnd write, 128KB, QD=1, 1 job : IOPS=1820, BW=228MiB/s (239MB/s)
Rnd write, 128KB, QD=32, 1 job : IOPS=5703, BW=713MiB/s (748MB/s)
Rnd write, 128KB, QD=32, 4 jobs: IOPS=5813, BW=727MiB/s (762MB/s)
Seq read, 128KB, QD=1, 1 job : IOPS=1958, BW=245MiB/s (257MB/s)
Seq read, 128KB, QD=32, 1 job : IOPS=18.8k, BW=2345MiB/s (2459MB/s)
Seq read, 512KB, QD=1, 1 job : IOPS=1319, BW=660MiB/s (692MB/s)
Seq read, 512KB, QD=32, 1 job : IOPS=4542, BW=2271MiB/s (2382MB/s)
Seq read, 1MB, QD=32, 1 job : IOPS=2325, BW=2325MiB/s (2438MB/s)
Seq write, 128KB, QD=1, 1 job : IOPS=2174, BW=272MiB/s (285MB/s)
Seq write, 128KB, QD=32, 1 job : IOPS=5697, BW=712MiB/s (747MB/s)
Seq write, 512KB, QD=1, 1 job : IOPS=1035, BW=518MiB/s (543MB/s)
Seq write, 512KB, QD=32, 1 job : IOPS=1462, BW=731MiB/s (767MB/s)
Seq write, 1MB, QD=32, 1 job : IOPS=720, BW=721MiB/s (756MB/s)
Rnd rdwr, 4K..1MB, QD=8, 4 jobs: IOPS=2029, BW=1018MiB/s (1067MB/s)
IOPS=2037, BW=1023MiB/s (1072MB/s)

Small performance boost, but I think the nicest thing with this series is
to be able to remove the ugly mutex in pci-epf.c.

Kind regards,
Niklas