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authorWilco Dijkstra <Wilco.Dijkstra@arm.com>2019-01-29 17:43:45 +0000
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-03-22 17:30:44 -0300
commit7621e38bf3c58b2d0359545f1f2898017fd89d05 (patch)
treefbf712328d2d62a509d7a048e2fb22a5bf0f4b55 /benchtests/README
parent1e372ded4f83362509c8672ff501cba871bb1edc (diff)
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Add generic hp-timing support
Add missing generic hp_timing support.  It uses clock_gettime (CLOCK_MONOTONIC)
which has unspecified starting time, nano-second accuracy, and should faster on
architectures that implementes the symbol as vDSO.

Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu. I also
checked the builds for all afected ABIs.

	* benchtests/Makefile (USE_CLOCK_GETTIME) Remove.
	* benchtests/README: Update description.
	* benchtests/bench-timing.h: Default to hp-timing.
	* sysdeps/generic/hp-timing.h (HP_TIMING_DIFF, HP_TIMING_ACCUM_NT,
	HP_TIMING_PRINT): Remove.
	(HP_TIMING_NOW): Add generic implementation.
	(hp_timing_t): Change to uint64_t.
Diffstat (limited to 'benchtests/README')
-rw-r--r--benchtests/README7
1 files changed, 1 insertions, 6 deletions
diff --git a/benchtests/README b/benchtests/README
index aaf0b659e2..c4f03fd872 100644
--- a/benchtests/README
+++ b/benchtests/README
@@ -27,12 +27,7 @@ BENCH_DURATION.
 
 The benchmark suite does function call measurements using architecture-specific
 high precision timing instructions whenever available.  When such support is
-not available, it uses clock_gettime (CLOCK_PROCESS_CPUTIME_ID).  One can force
-the benchmark to use clock_gettime by invoking make as follows:
-
-  $ make USE_CLOCK_GETTIME=1 bench
-
-Again, one must run `make bench-clean' before changing the measurement method.
+not available, it uses clock_gettime (CLOCK_MONOTONIC).
 
 On x86 processors, RDTSCP instruction provides more precise timing data
 than RDTSC instruction.  All x86 processors since 2010 support RDTSCP