On Sat, 2019-03-16 at 14:42 +0000, Wiles, Keith wrote: > > On Mar 16, 2019, at 2:03 AM, Pavan Nikhilesh Bhagavatula < > > pbhagavat...@marvell.com> wrote: > > > > From: Pavan Nikhilesh <pbhagavat...@marvell.com> > > > > When estimating tsc frequency using sleep/gettime round it up to > > the > > nearest multiple of 10Mhz for more accuracy. > > > > Signed-off-by: Pavan Nikhilesh <pbhagavat...@marvell.com> > > --- > > Useful in case of ARM64 if we enable RTE_ARM_EAL_RDTSC_USE_PMU, > > get_tsc_freq_arch() will return 0 as there is no instruction to > > determine > > the clk of PMU and eal falls back to sleep(1). > > > > lib/librte_eal/common/eal_common_timer.c | 4 ++-- > > lib/librte_eal/linuxapp/eal/eal_timer.c | 2 +- > > 2 files changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/lib/librte_eal/common/eal_common_timer.c > > b/lib/librte_eal/common/eal_common_timer.c > > index dcf26bfea..1358bbed0 100644 > > --- a/lib/librte_eal/common/eal_common_timer.c > > +++ b/lib/librte_eal/common/eal_common_timer.c > > @@ -69,7 +69,7 @@ estimate_tsc_freq(void) > > /* assume that the sleep(1) will sleep for 1 second */ > > uint64_t start = rte_rdtsc(); > > sleep(1); > > - return rte_rdtsc() - start; > > + return RTE_ALIGN_MUL_NEAR(rte_rdtsc() - start, 1E7); > > } > > > > void > > @@ -83,7 +83,7 @@ set_tsc_freq(void) > > if (!freq) > > freq = estimate_tsc_freq(); > > > > - RTE_LOG(DEBUG, EAL, "TSC frequency is ~%" PRIu64 " KHz\n", freq > > / 1000); > > + RTE_LOG(INFO, EAL, "TSC frequency is ~%" PRIu64 " Hz\n", freq); > > eal_tsc_resolution_hz = freq;
I missed this log will remove it in the next version. > > } > > > > diff --git a/lib/librte_eal/linuxapp/eal/eal_timer.c > > b/lib/librte_eal/linuxapp/eal/eal_timer.c > > index bc8f05199..864d6ef29 100644 > > --- a/lib/librte_eal/linuxapp/eal/eal_timer.c > > +++ b/lib/librte_eal/linuxapp/eal/eal_timer.c > > @@ -248,7 +248,7 @@ get_tsc_freq(void) > > > > double secs = (double)ns/NS_PER_SEC; > > tsc_hz = (uint64_t)((end - start)/secs); > > - return tsc_hz; > > + return RTE_ALIGN_MUL_NEAR(tsc_hz, 1E7); > > Maybe I missed an email about this, but why would I want the TSC hz > rounded here? I do not mind the macro just the fact that we are > changing TSC hz value. If the TSC value is wrong then we need to fix > the value, but I do not see it being wrong here. Since in this function nanosleep might not be cycle accurate we need to round it up. Please note that estimation only applies when get_tsc_freq_arch() fails. i.e there is no CPU instruction that specifies the cyc/sec. As I mentioned in the patch notes "Useful in case of ARM64 if we enable RTE_ARM_EAL_RDTSC_USE_PMU, get_tsc_freq_arch() will return 0 as there is no instruction to determine the clock of PMU and eal falls back to sleep(1)/nanosleep." > > } > > #endif > > return 0; > > -- > > 2.21.0 > > > > Regards, > Keith >
