Change in v3: - Use "mrq->data->blksz * mrq->data->blocks == 4096" for 4K. - Add explanation for "HSQ_PERFORMANCE_DEPTH". Change in v2: - Support for dynamic adjustment of hsq_depth. Test ===== I tested 3 times for each case and output a average speed. Ran 'fio' to evaluate the performance: 1.Fixed hsq_depth 1) Sequential write: Speed: 168 164 165 Average speed: 165.67MB/S 2) Sequential read: Speed: 326 326 326 Average speed: 326MB/S 3) Random write: Speed: 82.6 83 83 Average speed: 82.87MB/S 4) Random read: Speed: 48.2 48.3 47.6 Average speed: 48.03MB/S 2.Dynamic hsq_depth 1) Sequential write: Speed: 167 166 166 Average speed: 166.33MB/S 2) Sequential read: Speed: 327 326 326 Average speed: 326.3MB/S 3) Random write: Speed: 86.1 86.2 87.7 Average speed: 86.67MB/S 4) Random read: Speed: 48.1 48 48 Average speed: 48.03MB/S Based on the above data, dynamic hsq_depth can improve the performance of random writes. Random write improved by 4.6%. In addition, we tested 8K and 16K. 1.Fixed hsq_depth 1) Random write(bs=8K): Speed: 116 114 115 Average speed: 115MB/S 2) Random read(bs=8K): Speed: 83 83 82.5 Average speed: 82.8MB/S 3) Random write(bs=16K): Speed: 141 142 141 Average speed: 141.3MB/S 4) Random read(bs=16K): Speed: 132 132 132 Average speed: 132MB/S 2.Dynamic hsq_depth(mrq->data->blksz * mrq->data->blocks == 8192 or 16384) 1) Random write(bs=8K): Speed: 115 115 115 Average speed: 115MB/S 2) Random read(bs=8K): Speed: 82.7 82.9 82.8 Average speed: 82.8MB/S 3) Random write(bs=16K): Speed: 143 141 141 Average speed: 141.6MB/S 4) Random read(bs=16K): Speed: 132 132 132 Average speed: 132MB/S Increasing hsq_depth cannot improve 8k and 16k random read/write performance. To reduce latency, we dynamically increase hsq_depth only for 4k random writes. Test cmd ========= 1)write: fio -filename=/dev/mmcblk0p72 -direct=1 -rw=write -bs=512K -size=512M -group_reporting -name=test -numjobs=8 -thread -iodepth=64 2)read: fio -filename=/dev/mmcblk0p72 -direct=1 -rw=read -bs=512K -size=512M -group_reporting -name=test -numjobs=8 -thread -iodepth=64 3)randwrite: fio -filename=/dev/mmcblk0p72 -direct=1 -rw=randwrite -bs=4K -size=512M -group_reporting -name=test -numjobs=8 -thread -iodepth=64 4)randread: fio -filename=/dev/mmcblk0p72 -direct=1 -rw=randread -bs=4K -size=512M -group_reporting -name=test -numjobs=8 -thread -iodepth=64 5)randwrite: fio -filename=/dev/mmcblk0p72 -direct=1 -rw=randwrite -bs=8K -size=512M -group_reporting -name=test -numjobs=8 -thread -iodepth=64 6)randread: fio -filename=/dev/mmcblk0p72 -direct=1 -rw=randread -bs=8K -size=512M -group_reporting -name=test -numjobs=8 -thread -iodepth=64 7)randwrite: fio -filename=/dev/mmcblk0p72 -direct=1 -rw=randwrite -bs=16K -size=512M -group_reporting -name=test -numjobs=8 -thread -iodepth=64 8)randread: fio -filename=/dev/mmcblk0p72 -direct=1 -rw=randread -bs=16K -size=512M -group_reporting -name=test -numjobs=8 -thread -iodepth=64 Wenchao Chen (2): mmc: queue: replace immediate with hsq->depth mmc: hsq: dynamic adjustment of hsq->depth drivers/mmc/core/queue.c | 6 +----- drivers/mmc/host/mmc_hsq.c | 28 ++++++++++++++++++++++++++++ drivers/mmc/host/mmc_hsq.h | 11 +++++++++++ include/linux/mmc/host.h | 1 + 4 files changed, 41 insertions(+), 5 deletions(-) -- 2.17.1
