On 19 December 2014 at 09:04, Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx> wrote: > Hello, > > Seems community already have some implementation for the eMMC5.1 device command > queue feature, but that require the eMMC host controller to support CMDQ. In my > platform, I don't have this kind of eMMC host controller but I have a > Samsung eMMC5.1 device which can support the Command queue. > > With this limitation, I have to let eMMC host controller to manually send the > CMD44/45/13/46/47. So in this way, more commands are needed for an I/O request, > more interrupts/schedule are needed in driver. > > Even this way have some more software overhead, but it can still use the eMMC5.1 > device Command queue feature. After test with the iozone command: > "iozone -zec -t 4 -i0 -i2 -F iozonefile1 iozonefile2 iozonefile3 iozonefile4 -+n > -I -r 4k -s 500m -O -R -+r -+D" to test random performance, I saw a performance > improvment for random read on my eMMC5.1 device: > > Random read > SW CMDQ: 5544.6 > Normal Read: 3993.05 Thanks for the patchset Chuanxiao! I will spend some time reviewing this in more detail as soon as I can. One important point though, before I start reviewing. I would like the "Normal read" to be performed for a host driver supporting the asynchronous mmc request feature. Currently sdhci don't support this, but there is patch suggesting to add this which you might want to use/review. https://www.marc.info/?l=linux-mmc&m=141811588607432&w=2 Kind regards Uffe > > So I want to send this serial patches as RFC patch for reviewing > > > Chuanxiao Dong (5): > mmc: replace sbc to precmd and add postcmd > mmc: host: add runtime PM for host class dev > mmc: queue: change mqrq_cur and mqrq_pre to mq qdepth > mmc: core: add support for CMDQ feature in MMC Core stack > mmc: sdhci: add SW CMDQ support for CHT SDHCI host > > drivers/mmc/card/block.c | 538 ++++++++++++++++++++++++++++++++++++++--- > drivers/mmc/card/queue.c | 213 ++++++++-------- > drivers/mmc/card/queue.h | 14 +- > drivers/mmc/core/core.c | 78 +++++- > drivers/mmc/core/host.c | 14 ++ > drivers/mmc/core/mmc.c | 43 +++- > drivers/mmc/host/dw_mmc.c | 8 +- > drivers/mmc/host/mmci.c | 14 +- > drivers/mmc/host/omap_hsmmc.c | 18 +- > drivers/mmc/host/sdhci-acpi.c | 1 - > drivers/mmc/host/sdhci-pci.c | 1 - > drivers/mmc/host/sdhci.c | 137 +++++++++-- > include/linux/mmc/card.h | 3 + > include/linux/mmc/core.h | 5 +- > include/linux/mmc/host.h | 5 + > include/linux/mmc/mmc.h | 21 ++ > include/linux/mmc/pm.h | 1 + > include/linux/mmc/sdhci.h | 1 + > 18 files changed, 909 insertions(+), 206 deletions(-) > > -- > 1.7.10.4 > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
