From: Purushotam Kumar Date: Mon, 19 May 2008 12:06:23 +0000 (+0530) Subject: MMC: Performance improvement for CONFIG_MMC_BLOCK_BOUNCE X-Git-Tag: v2.6.26-omap1~123^2~72 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b4dab1140a0a75c0cd622b5aa9faa2792e1e6e93;p=pandora-kernel.git MMC: Performance improvement for CONFIG_MMC_BLOCK_BOUNCE This patch will increase performance significantly.It is supposed that larger/bounce buffers will be used by mmc core if CONFIG_MMC_BLOCK_BOUNCE is defined. But, in the mmc core, size of buffer is set to mmc->max_req_size if mmc->max_req_size is smaller than MMC_QUEUE_BOUNCESZ i.e. bounce buffer size (which is 64KB).By default, mmc->max_req_size is set to 4K. So, buffers of 4K will be used instead of 64K even if CONFIG_MMC_BLOCK_BOUNCE is defined without this patch. This patches forces mmc core to use bounce buffer of size MMC_QUEUE_BOUNCESZ and so performance is increased. In my test environment, write and Read speed without this patch was 2.6Mbytes/sec and 2.7Mbytes/sec respectively whereas write and read performance with this patch has jumped to 4.4Mbytes/sec and 5MBytes/sec, respectively. This testing has been done on SD Extreme III high speed 2GB SD card using FAT file system with help of dd command Signed-off-by: Purushotam Kumar Signed-off-by: Tony Lindgren --- Reading git-diff-tree failed