[dpdk-dev] [PATCH 0/5] improve tsc frequency calibration

[dpdk-dev] [PATCH 0/5] improve tsc frequency calibration

[Jerin Jacob]

Some architecture like armv8 provides an architecture specific function
to get the rdtsc frequency. The existing rdtsc calibration scheme uses
OS serivce like sleep(1) to calibrate the frequency which may not
produce the accurate result. Introducing an architecture specific hook
to get the rdtsc frequency if architecture provides it. If not, use the
exiting the calibrate scheme to get the rdtsc frequency.

Jerin Jacob (5):
  eal/x86: define architecture specific rdtsc hz
  eal/ppc64: define architecture specific rdtsc hz
  eal/armv7: define architecture specific rdtsc hz
  eal/armv8: define architecture specific rdtsc hz
  eal/timer: honor architecture specific rdtsc hz function

 lib/librte_eal/common/eal_common_timer.c           |  5 +++-
 .../common/include/arch/arm/rte_cycles_32.h        | 13 ++++++++++
 .../common/include/arch/arm/rte_cycles_64.h        | 30 ++++++++++++++++++++++
 .../common/include/arch/ppc_64/rte_cycles.h        | 13 ++++++++++
 .../common/include/arch/x86/rte_cycles.h           | 13 ++++++++++
 5 files changed, 73 insertions(+), 1 deletion(-)

-- 
2.14.0

[dpdk-dev] [PATCH 1/5] eal/x86: define architecture specific rdtsc hz

[Jerin Jacob]

CC: Bruce Richardson <bruce.richardson@intel.com>
CC: Konstantin Ananyev <konstantin.ananyev@intel.com>

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
---
 lib/librte_eal/common/include/arch/x86/rte_cycles.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/librte_eal/common/include/arch/x86/rte_cycles.h b/lib/librte_eal/common/include/arch/x86/rte_cycles.h
index 1bb3e1dbe..e2661e278 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_cycles.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_cycles.h
@@ -77,6 +77,19 @@ rte_rdtsc(void)
 	return tsc.tsc_64;
 }
 
+/**
+ * Get the number of rdtsc cycles in one second if the architecture supports.
+ *
+ * @return
+ *   The number of rdtsc cycles in one second. Return zero if the architecture
+ *   support is not available.
+ */
+static inline uint64_t
+rte_rdtsc_arch_hz(void)
+{
+	return 0;
+}
+
 static inline uint64_t
 rte_rdtsc_precise(void)
 {
-- 
2.14.0

Re: [dpdk-dev] [PATCH 1/5] eal/x86: define architecture specific rdtsc hz

[Burakov, Anatoly]

On 13-Aug-17 8:03 AM, jerin.jacob at caviumnetworks.com (Jerin Jacob) wrote:
> CC: Bruce Richardson <bruce.richardson at intel.com>
> CC: Konstantin Ananyev <konstantin.ananyev at intel.com>
> 
> Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
> ---

Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

[dpdk-dev] [PATCH 2/5] eal/ppc64: define architecture specific rdtsc hz

[Jerin Jacob]

CC: Chao Zhu <chaozhu@linux.vnet.ibm.com>
Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
---
 lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
index 8fa6fc60b..20243fb29 100644
--- a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
+++ b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
@@ -79,6 +79,19 @@ rte_rdtsc(void)
 	return tsc.tsc_64;
 }
 
+/**
+ * Get the number of rdtsc cycles in one second if the architecture supports.
+ *
+ * @return
+ *   The number of rdtsc cycles in one second. Return zero if the architecture
+ *   support is not available.
+ */
+static inline uint64_t
+rte_rdtsc_arch_hz(void)
+{
+	return 0;
+}
+
 static inline uint64_t
 rte_rdtsc_precise(void)
 {
-- 
2.14.0

Re: [dpdk-dev] [PATCH 2/5] eal/ppc64: define architecture specific rdtsc hz

[Chao Zhu]

> -----Original Message-----
> From: Jerin Jacob [mailto:jerin.jacob@caviumnetworks.com]
> Sent: 2017年8月13日 15:04
> To: dev@dpdk.org
> Cc: thomas@monjalon.net; bruce.richardson@intel.com;
> konstantin.ananyev@intel.com; viktorin@rehivetech.com;
> jianbo.liu@linaro.org; chaozhu@linux.vnet.ibm.com; Jerin Jacob
> <jerin.jacob@caviumnetworks.com>
> Subject: [dpdk-dev] [PATCH 2/5] eal/ppc64: define architecture specific
rdtsc hz
> 
> CC: Chao Zhu <chaozhu@linux.vnet.ibm.com>
> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> ---
>  lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
> b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
> index 8fa6fc60b..20243fb29 100644
> --- a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
> +++ b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
> @@ -79,6 +79,19 @@ rte_rdtsc(void)
>  	return tsc.tsc_64;
>  }
> 
> +/**
> + * Get the number of rdtsc cycles in one second if the architecture
supports.
> + *
> + * @return
> + *   The number of rdtsc cycles in one second. Return zero if the
architecture
> + *   support is not available.
> + */
> +static inline uint64_t
> +rte_rdtsc_arch_hz(void)
> +{
> +	return 0;
> +}
> +
>  static inline uint64_t
>  rte_rdtsc_precise(void)
>  {
> --
> 2.14.0
Acked-by: Chao Zhu <chaozhu@linux.vnet.ibm.com>

[dpdk-dev] [PATCH 3/5] eal/armv7: define architecture specific rdtsc hz

[Jerin Jacob]

CC: Jan Viktorin <viktorin@rehivetech.com>
CC: Jianbo Liu <jianbo.liu@linaro.org>
Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
---
 lib/librte_eal/common/include/arch/arm/rte_cycles_32.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h b/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h
index 9c1be71ea..68d7462c4 100644
--- a/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h
+++ b/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h
@@ -104,6 +104,19 @@ __rte_rdtsc_pmccntr(void)
 
 #endif /* RTE_ARM_EAL_RDTSC_USE_PMU */
 
+/**
+ * Get the number of rdtsc cycles in one second if the architecture supports.
+ *
+ * @return
+ *   The number of rdtsc cycles in one second. Return zero if the architecture
+ *   support is not available.
+ */
+static inline uint64_t
+rte_rdtsc_arch_hz(void)
+{
+	return 0;
+}
+
 static inline uint64_t
 rte_rdtsc_precise(void)
 {
-- 
2.14.0

[dpdk-dev] [PATCH 4/5] eal/armv8: define architecture specific rdtsc hz

[Jerin Jacob]

Use cntvct_el0 system register to get the system counter frequency.

If the system is configured with RTE_ARM_EAL_RDTSC_USE_PMU then
return 0(let the common code calibrate the tsc frequency).

CC: Jianbo Liu <jianbo.liu@linaro.org>
Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
---
 .../common/include/arch/arm/rte_cycles_64.h        | 30 ++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/lib/librte_eal/common/include/arch/arm/rte_cycles_64.h b/lib/librte_eal/common/include/arch/arm/rte_cycles_64.h
index 154576910..5b95cb67d 100644
--- a/lib/librte_eal/common/include/arch/arm/rte_cycles_64.h
+++ b/lib/librte_eal/common/include/arch/arm/rte_cycles_64.h
@@ -58,6 +58,23 @@ rte_rdtsc(void)
 	asm volatile("mrs %0, cntvct_el0" : "=r" (tsc));
 	return tsc;
 }
+
+/**
+ * Get the number of rdtsc cycles in one second if the architecture supports.
+ *
+ * @return
+ *   The number of rdtsc cycles in one second. Return zero if the architecture
+ *   support is not available.
+ */
+static inline uint64_t
+rte_rdtsc_arch_hz(void)
+{
+	uint64_t freq;
+
+	asm volatile("mrs %0, cntfrq_el0" : "=r" (freq));
+	return freq;
+}
+
 #else
 /**
  * This is an alternative method to enable rte_rdtsc() with high resolution
@@ -85,6 +102,19 @@ rte_rdtsc(void)
 	asm volatile("mrs %0, pmccntr_el0" : "=r"(tsc));
 	return tsc;
 }
+
+/**
+ * Get the number of rdtsc cycles in one second if the architecture supports.
+ *
+ * @return
+ *   The number of rdtsc cycles in one second. Return zero if the architecture
+ *   support is not available.
+ */
+static inline uint64_t
+rte_rdtsc_arch_hz(void)
+{
+	return 0;
+}
 #endif
 
 static inline uint64_t
-- 
2.14.0

Re: [dpdk-dev] [PATCH 4/5] eal/armv8: define architecture specific rdtsc hz

[Jianbo Liu]

On 13 August 2017 at 15:03, Jerin Jacob <jerin.jacob@caviumnetworks.com> wrote:
> Use cntvct_el0 system register to get the system counter frequency.
>
> If the system is configured with RTE_ARM_EAL_RDTSC_USE_PMU then
> return 0(let the common code calibrate the tsc frequency).
>
> CC: Jianbo Liu <jianbo.liu@linaro.org>
> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> ---
>  .../common/include/arch/arm/rte_cycles_64.h        | 30 ++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
>
> diff --git a/lib/librte_eal/common/include/arch/arm/rte_cycles_64.h b/lib/librte_eal/common/include/arch/arm/rte_cycles_64.h
> index 154576910..5b95cb67d 100644
> --- a/lib/librte_eal/common/include/arch/arm/rte_cycles_64.h
> +++ b/lib/librte_eal/common/include/arch/arm/rte_cycles_64.h
> @@ -58,6 +58,23 @@ rte_rdtsc(void)
>         asm volatile("mrs %0, cntvct_el0" : "=r" (tsc));
>         return tsc;
>  }
> +
> +/**
> + * Get the number of rdtsc cycles in one second if the architecture supports.
> + *
> + * @return
> + *   The number of rdtsc cycles in one second. Return zero if the architecture
> + *   support is not available.
> + */
> +static inline uint64_t
> +rte_rdtsc_arch_hz(void)
> +{
> +       uint64_t freq;
> +
> +       asm volatile("mrs %0, cntfrq_el0" : "=r" (freq));
> +       return freq;
> +}
> +
>  #else
>  /**
>   * This is an alternative method to enable rte_rdtsc() with high resolution
> @@ -85,6 +102,19 @@ rte_rdtsc(void)
>         asm volatile("mrs %0, pmccntr_el0" : "=r"(tsc));
>         return tsc;
>  }
> +
> +/**
> + * Get the number of rdtsc cycles in one second if the architecture supports.
> + *
> + * @return
> + *   The number of rdtsc cycles in one second. Return zero if the architecture
> + *   support is not available.
> + */
> +static inline uint64_t
> +rte_rdtsc_arch_hz(void)
> +{
> +       return 0;
> +}
>  #endif
>
>  static inline uint64_t
> --
> 2.14.0
>

Acked-by: Jianbo Liu <jianbo.liu@linaro.org>

[dpdk-dev] [PATCH 5/5] eal/timer: honor architecture specific rdtsc hz function

[Jerin Jacob]

When calibrating the tsc frequency, first, probe the architecture specific
rdtsc hz function. if not available, use the existing calibrate scheme
to calibrate the tsc frequency.

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
---
 lib/librte_eal/common/eal_common_timer.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/librte_eal/common/eal_common_timer.c b/lib/librte_eal/common/eal_common_timer.c
index ed0b16d05..978edaed7 100644
--- a/lib/librte_eal/common/eal_common_timer.c
+++ b/lib/librte_eal/common/eal_common_timer.c
@@ -80,8 +80,11 @@ estimate_tsc_freq(void)
 void
 set_tsc_freq(void)
 {
-	uint64_t freq = get_tsc_freq();
+	uint64_t freq;
 
+	freq = rte_rdtsc_arch_hz();
+	if (!freq)
+		freq = get_tsc_freq();
 	if (!freq)
 		freq = estimate_tsc_freq();
 
-- 
2.14.0