[4/4] event/octeontx2: timer always use virtual counter
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Commit Message
From: Pavan Nikhilesh <pbhagavatula@marvell.com>
Use virtual counter for estimating current bucket as PMU cannot be
reliably used to estimate time.
Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
---
drivers/event/octeontx2/otx2_tim_evdev.c | 19 +++-----------
drivers/event/octeontx2/otx2_tim_evdev.h | 32 +++++++++++++++++++++++
drivers/event/octeontx2/otx2_tim_worker.c | 4 +--
drivers/event/octeontx2/otx2_tim_worker.h | 2 +-
4 files changed, 38 insertions(+), 19 deletions(-)
Comments
On Thu, Feb 25, 2021 at 5:53 PM <pbhagavatula@marvell.com> wrote:
>
> From: Pavan Nikhilesh <pbhagavatula@marvell.com>
>
> Use virtual counter for estimating current bucket as PMU cannot be
> reliably used to estimate time.
>
> Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
>
> +#ifdef RTE_ARCH_ARM64
> +static inline uint64_t
> +tim_cntvct(void)
> +{
> + uint64_t tsc;
> +
> + asm volatile("mrs %0, cntvct_el0" : "=r"(tsc));
> + return tsc;
Reuse __rte_arm64_cntvct()
> +}
> +
> +static inline uint64_t
> +tim_cntfrq(void)
> +{
> + uint64_t freq;
> +
> + asm volatile("mrs %0, cntfrq_el0" : "=r"(freq));
> + return freq;
Reuse __rte_arm64_cntfrq()
Please fix the following checkpatch and check format errors too.
[1]
Wrong headline case:
"event/octeontx2: optimize timer arm routine":
arm --> Arm
Invalid patch(es) found - checked 4 patches
[2]
total: 0 errors, 47 warnings, 272 lines checked
Warning in drivers/event/octeontx2/otx2_tim_worker.h:
Using rte_smp_[r/w]mb
Warning in drivers/event/octeontx2/otx2_tim_worker.c:
Using __atomic_thread_fence
>
>-----Original Message-----
>From: Jerin Jacob <jerinjacobk@gmail.com>
>Sent: Saturday, March 20, 2021 7:04 PM
>To: Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>
>Cc: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; dpdk-dev
><dev@dpdk.org>
>Subject: [EXT] Re: [dpdk-dev] [PATCH 4/4] event/octeontx2: timer
>always use virtual counter
>
>External Email
>
>----------------------------------------------------------------------
>On Thu, Feb 25, 2021 at 5:53 PM <pbhagavatula@marvell.com> wrote:
>>
>> From: Pavan Nikhilesh <pbhagavatula@marvell.com>
>>
>> Use virtual counter for estimating current bucket as PMU cannot be
>> reliably used to estimate time.
>>
>> Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
>
>>
>> +#ifdef RTE_ARCH_ARM64
>> +static inline uint64_t
>> +tim_cntvct(void)
>> +{
>> + uint64_t tsc;
>> +
>> + asm volatile("mrs %0, cntvct_el0" : "=r"(tsc));
>> + return tsc;
>
>
>Reuse __rte_arm64_cntvct()
>
>> +}
>> +
>> +static inline uint64_t
>> +tim_cntfrq(void)
>> +{
>> + uint64_t freq;
>> +
>> + asm volatile("mrs %0, cntfrq_el0" : "=r"(freq));
>> + return freq;
>
>
>Reuse __rte_arm64_cntfrq()
Ack.
>
>
>Please fix the following checkpatch and check format errors too.
>
>
>[1]
>Wrong headline case:
> "event/octeontx2: optimize timer arm routine":
>arm --> Arm
I think checkpatch is interpreting this as Arm Inc. which I think we
can ignore it in this context.
>
>Invalid patch(es) found - checked 4 patches
>
>
>[2]
>total: 0 errors, 47 warnings, 272 lines checked
>Warning in drivers/event/octeontx2/otx2_tim_worker.h:
>Using rte_smp_[r/w]mb
>Warning in drivers/event/octeontx2/otx2_tim_worker.c:
>Using __atomic_thread_fence
>
Ack.
>
>>
@@ -354,7 +354,7 @@ otx2_tim_calibrate_start_tsc(struct otx2_tim_ring *tim_ring)
for (icount = 0; icount < OTX2_TIM_CALIB_ITER; icount++) {
real_bkt = otx2_read64(tim_ring->base + TIM_LF_RING_REL) >> 44;
- bkt_cyc = rte_rdtsc();
+ bkt_cyc = tim_cntvct();
bucket = (bkt_cyc - tim_ring->ring_start_cyc) /
tim_ring->tck_int;
bucket = bucket % (tim_ring->nb_bkts);
@@ -389,20 +389,8 @@ otx2_tim_ring_start(const struct rte_event_timer_adapter *adptr)
tim_err_desc(rc);
goto fail;
}
-#ifdef RTE_ARM_EAL_RDTSC_USE_PMU
- uint64_t tenns_stmp, tenns_diff;
- uint64_t pmu_stmp;
-
- pmu_stmp = rte_rdtsc();
- asm volatile("mrs %0, cntvct_el0" : "=r" (tenns_stmp));
-
- tenns_diff = tenns_stmp - rsp->timestarted;
- pmu_stmp = pmu_stmp - (NSEC2TICK(tenns_diff * 10, rte_get_timer_hz()));
- tim_ring->ring_start_cyc = pmu_stmp;
-#else
tim_ring->ring_start_cyc = rsp->timestarted;
-#endif
- tim_ring->tck_int = NSEC2TICK(tim_ring->tck_nsec, rte_get_timer_hz());
+ tim_ring->tck_int = NSEC2TICK(tim_ring->tck_nsec, tim_cntfrq());
tim_ring->tot_int = tim_ring->tck_int * tim_ring->nb_bkts;
tim_ring->fast_div = rte_reciprocal_value_u64(tim_ring->tck_int);
tim_ring->fast_bkt = rte_reciprocal_value_u64(tim_ring->nb_bkts);
@@ -470,8 +458,7 @@ otx2_tim_stats_get(const struct rte_event_timer_adapter *adapter,
struct rte_event_timer_adapter_stats *stats)
{
struct otx2_tim_ring *tim_ring = adapter->data->adapter_priv;
- uint64_t bkt_cyc = rte_rdtsc() - tim_ring->ring_start_cyc;
-
+ uint64_t bkt_cyc = tim_cntvct() - tim_ring->ring_start_cyc;
stats->evtim_exp_count = __atomic_load_n(&tim_ring->arm_cnt,
__ATOMIC_RELAXED);
@@ -176,6 +176,38 @@ tim_priv_get(void)
return mz->addr;
}
+#ifdef RTE_ARCH_ARM64
+static inline uint64_t
+tim_cntvct(void)
+{
+ uint64_t tsc;
+
+ asm volatile("mrs %0, cntvct_el0" : "=r"(tsc));
+ return tsc;
+}
+
+static inline uint64_t
+tim_cntfrq(void)
+{
+ uint64_t freq;
+
+ asm volatile("mrs %0, cntfrq_el0" : "=r"(freq));
+ return freq;
+}
+#else
+static inline uint64_t
+tim_cntvct(void)
+{
+ return 0;
+}
+
+static inline uint64_t
+tim_cntfrq(void)
+{
+ return 0;
+}
+#endif
+
#define TIM_ARM_FASTPATH_MODES \
FP(sp, 0, 0, 0, OTX2_TIM_ENA_DFB | OTX2_TIM_SP) \
FP(mp, 0, 0, 1, OTX2_TIM_ENA_DFB | OTX2_TIM_MP) \
@@ -41,12 +41,12 @@ tim_format_event(const struct rte_event_timer * const tim,
static inline void
tim_sync_start_cyc(struct otx2_tim_ring *tim_ring)
{
- uint64_t cur_cyc = rte_rdtsc();
+ uint64_t cur_cyc = tim_cntvct();
uint32_t real_bkt;
if (cur_cyc - tim_ring->last_updt_cyc > tim_ring->tot_int) {
real_bkt = otx2_read64(tim_ring->base + TIM_LF_RING_REL) >> 44;
- cur_cyc = rte_rdtsc();
+ cur_cyc = tim_cntvct();
tim_ring->ring_start_cyc = cur_cyc -
(real_bkt * tim_ring->tck_int);
@@ -132,7 +132,7 @@ tim_get_target_bucket(struct otx2_tim_ring *const tim_ring,
const uint32_t rel_bkt, struct otx2_tim_bkt **bkt,
struct otx2_tim_bkt **mirr_bkt)
{
- const uint64_t bkt_cyc = rte_rdtsc() - tim_ring->ring_start_cyc;
+ const uint64_t bkt_cyc = tim_cntvct() - tim_ring->ring_start_cyc;
uint64_t bucket =
rte_reciprocal_divide_u64(bkt_cyc, &tim_ring->fast_div) +
rel_bkt;