evie/android_kernel_oneplus_msm8998
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mmc: core: capture performance numbers only when asked

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Currently performance numbers are captured for each SDCC
transfers unconditionally which may add the overhead and
could reduce the SDCC read/write throughput numbers.

This change adds additional control for enabling/disabling the
capturing of performance numbers at runtime. We already have sysfs
entry named "perf" for msm sdcc devices. Currently setting this
entry to 0 clears the performance statistics. But now we are
changing the definition of this entry as mentioned below:

Disable performance capturing and clear the performance statistics:
	"echo 0 > /sys/devices/platform/msm_sdcc.<n>/perf"

Enable performance capturing:
	"echo 1 > /sys/devices/platform/msm_sdcc.<n>/perf"

CRs-fixed: 345170
Change-Id: I3ab9288fd87cc8a8ada6c0c3d066cac4f68d79b7
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
This commit is contained in:
Subhash Jadavani 2012-03-25 11:15:41 +05:30
parent 0f618d04ba
commit 9a09218381
3 changed files with 24 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
drivers/mmc/core/core.c
View file

@ -179,17 +179,21 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
if (mrq->data) {
#ifdef CONFIG_MMC_PERF_PROFILING
diff = ktime_sub(ktime_get(), host->perf.start);
if (mrq->data->flags == MMC_DATA_READ) {
host->perf.rbytes_drv +=
if (host->perf_enable) {
diff = ktime_sub(ktime_get(), host->perf.start);
if (mrq->data->flags == MMC_DATA_READ) {
host->perf.rbytes_drv +=
mrq->data->bytes_xfered;
host->perf.rtime_drv =
ktime_add(host->perf.rtime_drv,
diff);
} else {
host->perf.wbytes_drv +=
mrq->data->bytes_xfered;
host->perf.rtime_drv =
ktime_add(host->perf.rtime_drv, diff);
} else {
host->perf.wbytes_drv +=
mrq->data->bytes_xfered;
host->perf.wtime_drv =
ktime_add(host->perf.wtime_drv, diff);
host->perf.wtime_drv =
ktime_add(host->perf.wtime_drv,
diff);
}
}
#endif
pr_debug("%s: %d bytes transferred: %d\n",
@ -313,7 +317,8 @@ static int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
mrq->stop->mrq = mrq;
}
#ifdef CONFIG_MMC_PERF_PROFILING
host->perf.start = ktime_get();
if (host->perf_enable)
host->perf.start = ktime_get();
#endif
}
mmc_host_clk_hold(host);

9
drivers/mmc/core/host.c
View file

@ -651,18 +651,23 @@ set_perf(struct device *dev, struct device_attribute *attr,
{
int64_t value;
struct mmc_host *host = dev_get_drvdata(dev);
sscanf(buf, "%lld", &value);
spin_lock(&host->lock);
if (!value) {
spin_lock(&host->lock);
memset(&host->perf, 0, sizeof(host->perf));
spin_unlock(&host->lock);
host->perf_enable = false;
} else {
host->perf_enable = true;
}
spin_unlock(&host->lock);
return count;
}
static DEVICE_ATTR(perf, S_IRUGO | S_IWUSR,
show_perf, set_perf);
#endif
static struct attribute *dev_attrs[] = {

1
include/linux/mmc/host.h
View file

@ -442,6 +442,7 @@ struct mmc_host {
ktime_t wtime_drv; /* Wr time MMC Host */
ktime_t start;
} perf;
bool perf_enable;
#endif
unsigned long private[0] ____cacheline_aligned;