lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 18 Jul 2014 01:41:34 +0200 From: Apelete Seketeli <apelete@...eteli.net> To: Chris Ball <chris@...ntf.net>, Ulf Hansson <ulf.hansson@...aro.org>, H Hartley Sweeten <hsweeten@...ionengravers.com>, Lars-Peter Clausen <lars@...afoo.de>, Wei Yongjun <yongjun_wei@...ndmicro.com.cn>, Alex Smith <alex.smith@...tec.com>, Laurent Pinchart <laurent.pinchart+renesas@...asonboard.com>, linux-mmc@...r.kernel.org Cc: linux-kernel@...r.kernel.org Subject: [PATCH v5] Use DMA for data transfers in JZ4740 MMC driver Hello, MMC driver for JZ4740 SoC is currently relying on PIO mode only for data transfers. The patch that comes as a follow-up of this message allows the use of DMA for data transfers. Changes since v4: - prefix functions with jz4740_mmc_ instead of jz4740_ to keep consistency with the rest of the code, - test (host->sg_len == 0) instead of (host->sg_len < 0) after dma_map_sg() in jz4740_mmc_start_dma_transfer() according to dmaengine.txt instructions. Changes since v3: - use DMA engine device instead of MMC device in dma_map_sg() and dma_unmap_sg() as the memory transfers will be performed by the DMA engine, - remove unnecessary mem_res == NULL check in jz4740_mmc_probe() since devm_ioremap_resource() handles the mem_res == NULL case and print a message, - added a check to host->use_dma in jz4740_mmc_remove() to avoid calling jz4740_release_dma_channels() unnecessarily. Changes since v2: - declare sg_len member of struct jz4740_mmc_host as int instead of unsigned int. Changes since v1: - remove blank line added by mistake in jz_mmc_prepare_data_transfer(). According to the following DMA vs PIO benchmarks there seems to be a slight improvement in transfer speed with the Ben NanoNote booting from SD card, while load average seems to be roughly on par: * With DMA: Test cases | root@...NanoNote:/# uptime | root@...NanoNote:/# time zcat root/fedora-16.iso.gz > /dev/null && uptime -----------|---------------------------------------------------------------------------------------------------------------------------------- Test run 1 | 00:20:55 up 1 min, load average: 1.26, 0.42, 0.14 | 00:26:10 up 6 min, load average: 2.89, 1.94, 0.89 Test run 2 | 00:30:22 up 1 min, load average: 1.16, 0.38, 0.13 | 00:35:34 up 6 min, load average: 2.68, 1.86, 0.85 Test run 3 | 00:39:56 up 1 min, load average: 1.16, 0.38, 0.13 | 00:45:06 up 6 min, load average: 2.57, 1.76, 0.81 -----------|---------------------------------------------------------------------------------------------------------------------------------- Average | 1 min, load average: 1.19, 0.39, 0.13 | 6 min, load average: 2.71, 1.85, 0.85 * With PIO: Test cases | root@...NanoNote:/# uptime | root@...NanoNote:/# time zcat root/fedora-16.iso.gz > /dev/null && uptime ---------------------------------------------------------------------------------------------------------------------------------------------- Test run 1 | 00:50:47 up 1 min, load average: 1.42, 0.49, 0.17 | 00:56:52 up 7 min, load average: 2.47, 2.00, 0.98 Test run 2 | 01:00:19 up 1 min, load average: 1.21, 0.39, 0.14 | 01:06:29 up 7 min, load average: 2.45, 1.96, 0.96 Test run 3 | 01:11:27 up 1 min, load average: 1.15, 0.36, 0.12 | 01:17:33 up 7 min, load average: 2.63, 2.01, 0.97 -----------|---------------------------------------------------------------------------------------------------------------------------------- Average | 1 min, load average: 1.26, 0.41, 0.14 | 7 min, load average: 2.52, 1.99, 0.97 DMA transfers performance might be further improved with a latter patch by taking advantage of the asynchronous request capability of the MMC framework. Changes were rebased on top of linux master branch, built and tested successfully. The following changes since commit 1795cd9: Linux 3.16-rc5 are available in the git repository at: git://git.seketeli.net/~apelete/linux.git jz4740-mmc-dma Apelete Seketeli (1): mmc: jz4740: add dma infrastructure for data transfers drivers/mmc/host/jz4740_mmc.c | 174 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 166 insertions(+), 8 deletions(-) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists