On Tuesday, July 23, 2013 11:24:37 PM Aaro Koskinen wrote: > Some functions on switch path use msleep() which is inaccurate, and > depends on HZ. With HZ=100 msleep(1) takes actually over ten times longer. > Using usleep_range() we get more accurate sleeps. > > I measured the "pfunc_slewing_done" polling to take 300us at max (on > 2.3GHz dual-processor Xserve G5), so using 500us sleep there should > be fine. > > With the patch, g5_switch_freq() duration drops from ~50ms to ~10ms on > Xserve with HZ=100. > > Signed-off-by: Aaro Koskinen <aaro.koski...@iki.fi>
All looks good in the patchset from 10000 feet (or more), but I need Ben to speak here. Thanks, Rafael > --- > drivers/cpufreq/pmac64-cpufreq.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/cpufreq/pmac64-cpufreq.c > b/drivers/cpufreq/pmac64-cpufreq.c > index 7ba4234..674807d 100644 > --- a/drivers/cpufreq/pmac64-cpufreq.c > +++ b/drivers/cpufreq/pmac64-cpufreq.c > @@ -141,7 +141,7 @@ static void g5_vdnap_switch_volt(int speed_mode) > pmf_call_one(pfunc_vdnap0_complete, &args); > if (done) > break; > - msleep(1); > + usleep_range(1000, 1000); > } > if (done == 0) > printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n"); > @@ -240,7 +240,7 @@ static void g5_pfunc_switch_volt(int speed_mode) > if (pfunc_cpu1_volt_low) > pmf_call_one(pfunc_cpu1_volt_low, NULL); > } > - msleep(10); /* should be faster , to fix */ > + usleep_range(10000, 10000); /* should be faster , to fix */ > } > > /* > @@ -285,7 +285,7 @@ static int g5_pfunc_switch_freq(int speed_mode) > pmf_call_one(pfunc_slewing_done, &args); > if (done) > break; > - msleep(1); > + usleep_range(500, 500); > } > if (done == 0) > printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n"); > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
