From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavan Nikhilesh Bhagavatula Subject: [PATCH v3 2/2] eal: roundup tsc frequency when estimating Date: Sat, 16 Mar 2019 19:01:54 +0000 Message-ID: <20190316190119.6142-2-pbhagavatula@marvell.com> References: <20181129083138.23029-1-pbhagavatula@caviumnetworks.com> <20190316190119.6142-1-pbhagavatula@marvell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: "dev@dpdk.org" , Pavan Nikhilesh Bhagavatula To: Jerin Jacob Kollanukkaran , "keith.wiles@intel.com" , "stephen@networkplumber.org" , "thomas@monjalon.net" Return-path: Received: from mx0b-0016f401.pphosted.com (mx0b-0016f401.pphosted.com [67.231.156.173]) by dpdk.org (Postfix) with ESMTP id 379A711A4 for ; Sat, 16 Mar 2019 20:02:09 +0100 (CET) In-Reply-To: <20190316190119.6142-1-pbhagavatula@marvell.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" From: Pavan Nikhilesh When estimating tsc frequency using sleep/gettime round it up to the nearest multiple of 10Mhz for more accuracy. Signed-off-by: Pavan Nikhilesh Reviewed-by: Keith Wiles --- 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/linux/eal/eal_timer.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/lib/librte_eal/common/eal_common_timer.c b/lib/librte_eal/comm= on/eal_common_timer.c index dcf26bfea..68d67e684 100644 --- a/lib/librte_eal/common/eal_common_timer.c +++ b/lib/librte_eal/common/eal_common_timer.c @@ -64,12 +64,14 @@ rte_get_tsc_hz(void) static uint64_t estimate_tsc_freq(void) { +#define CYC_PER_10MHZ 1E7 RTE_LOG(WARNING, EAL, "WARNING: TSC frequency estimated roughly" " - clock timings may be less accurate.\n"); /* assume that the sleep(1) will sleep for 1 second */ uint64_t start =3D rte_rdtsc(); sleep(1); - return rte_rdtsc() - start; + /* Round up to 10Mhz. 1E7 ~ 10Mhz */ + return RTE_ALIGN_MUL_NEAR(rte_rdtsc() - start, CYC_PER_10MHZ); } void diff --git a/lib/librte_eal/linux/eal/eal_timer.c b/lib/librte_eal/linux/ea= l/eal_timer.c index bc8f05199..76ec17034 100644 --- a/lib/librte_eal/linux/eal/eal_timer.c +++ b/lib/librte_eal/linux/eal/eal_timer.c @@ -232,6 +232,7 @@ get_tsc_freq(void) { #ifdef CLOCK_MONOTONIC_RAW #define NS_PER_SEC 1E9 +#define CYC_PER_10MHZ 1E7 struct timespec sleeptime =3D {.tv_nsec =3D NS_PER_SEC / 10 }; /* 1/10 se= cond */ @@ -248,7 +249,8 @@ get_tsc_freq(void) double secs =3D (double)ns/NS_PER_SEC; tsc_hz =3D (uint64_t)((end - start)/secs); - return tsc_hz; + /* Round up to 10Mhz. 1E7 ~ 10Mhz */ + return RTE_ALIGN_MUL_NEAR(tsc_hz, CYC_PER_10MHZ); } #endif return 0; -- 2.21.0