RTE_ALIGN_MUL_NEAR is a macro so the cycle arguement could
get evaluated twice causing some potential skew. Fix by
computing value once.
Suggested by patch to fix side effects.
Fixes: 5cbd14b3e5f9 ("eal: roundup TSC frequency when estimating")
Cc: pbhagavat...@marvell.com
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
lib/eal/common/eal_common_timer.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/lib/eal/common/eal_common_timer.c
b/lib/eal/common/eal_common_timer.c
index 5686a5102b66..05614b0503cf 100644
--- a/lib/eal/common/eal_common_timer.c
+++ b/lib/eal/common/eal_common_timer.c
@@ -42,10 +42,14 @@ estimate_tsc_freq(void)
RTE_LOG(WARNING, EAL, "WARNING: TSC frequency estimated roughly"
" - clock timings may be less accurate.\n");
/* assume that the rte_delay_us_sleep() will sleep for 1 second */
- uint64_t start = rte_rdtsc();
+ uint64_t start, elapsed;
+
+ start = rte_rdtsc();
rte_delay_us_sleep(US_PER_S);
+ elapsed = rte_rdtsc() - start;
+
/* Round up to 10Mhz. 1E7 ~ 10Mhz */
- return RTE_ALIGN_MUL_NEAR(rte_rdtsc() - start, CYC_PER_10MHZ);
+ return RTE_ALIGN_MUL_NEAR(elapsed, CYC_PER_10MHZ);
}
void
--
2.39.2
