Hi,
On Fri, Apr 22, 2011 at 6:01 AM, Jaehoon Chung jh80.chung@samsung.com wrote:
Hi Andrei..
Did you test this patch with ADMA? I wonder that be increased performance or others..
FWIW...
ADMA
With changes
adb shell "echo 0 > /sys/module/sdhci/parameters/no_prepost" time adb shell "iozone -a -f /cache/file -g 4m > /mnt/obb/with"
real 0m37.245s user 0m0.010s sys 0m0.000s
Without changes
adb shell "echo 1 > /sys/module/sdhci/parameters/no_prepost" time adb shell "iozone -a -f /cache/file -g 4m > /mnt/obb/without"
real 0m38.400s user 0m0.000s sys 0m0.010s
SDMA plus BOUNCE_BUFFER
With changes
adb shell "echo 0 > /sys/module/sdhci/parameters/no_prepost" time adb shell "iozone -a -f /cache/file -g 4m > /mnt/obb/with"
real 0m37.999s user 0m0.000s sys 0m0.010s
Without changes
adb shell "echo 1 > /sys/module/sdhci/parameters/no_prepost" time adb shell "iozone -a -f /cache/file -g 4m > /mnt/obb/without"
real 0m39.717s user 0m0.000s sys 0m0.010s
Collected data using this patch on top of Shawn's...
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 3320c75..f698586 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -39,6 +39,7 @@ #endif
static unsigned int debug_quirks = 0; +static unsigned int no_prepost = 0;
static void sdhci_prepare_data(struct sdhci_host *, struct mmc_data *); static void sdhci_finish_data(struct sdhci_host *); @@ -1140,6 +1141,8 @@ static void sdhci_pre_req(struct mmc_host *mmc, struct mmc_request *mrq, bool is_first_req) { struct sdhci_host *host = mmc_priv(mmc); + if (no_prepost) + return;
if (mrq->data->host_cookie) { mrq->data->host_cookie = 0; @@ -1157,6 +1160,9 @@ static void sdhci_post_req(struct mmc_host *mmc, struct mmc_request *mrq, struct sdhci_host *host = mmc_priv(mmc); struct mmc_data *data = mrq->data;
+ if (no_prepost) + return; + if (host->flags & SDHCI_REQ_USE_DMA) { dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len, (data->flags & MMC_DATA_WRITE) ? @@ -2163,6 +2169,7 @@ module_init(sdhci_drv_init); module_exit(sdhci_drv_exit);
module_param(debug_quirks, uint, 0444); +module_param(no_prepost, uint, 0644);
MODULE_AUTHOR("Pierre Ossman pierre@ossman.eu"); MODULE_DESCRIPTION("Secure Digital Host Controller Interface core driver");
A