mmc: core: capture performance numbers only when asked
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>
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 362bdbe..7d34bfd 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -122,17 +122,21 @@
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",
@@ -210,7 +214,8 @@
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);
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 1985745..a162586 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -399,18 +399,23 @@
{
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[] = {
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 46f71a1..e19225e 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -352,6 +352,7 @@
ktime_t wtime_drv; /* Wr time MMC Host */
ktime_t start;
} perf;
+ bool perf_enable;
#endif
struct mmc_async_req *areq; /* active async req */