From patchwork Fri Feb 8 18:39:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella X-Patchwork-Id: 31367 Received: (qmail 77369 invoked by alias); 8 Feb 2019 18:39:26 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 77262 invoked by uid 89); 8 Feb 2019 18:39:25 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.2 spammy=Sum, 2712, Len X-HELO: mail-qt1-f196.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=xpzGUeUr4A5Zb759BBkshhgKpGaT6ZobE/CyjVTfibs=; b=y50uKpgA38SB3KrHFW0BHMjSYJV8iY4RLp8m5oOX+R9XkyC7+EEe88OX+86G+7zF/2 OvJbNXPk2u8qbXTsWFLUBmGpC4boRCuO/A7IrkCYGpe3R43dNNu8lykyiBglKneIu4nG fAWmyDVFaJ1LIICjt8KEjfXe9brYcCSiBPim8agJiKthDSzuPjBiedHS7yhKoUnupxir 0MemBidNbBoQFr8FoQMrUVF624UxBtNXsU4h6dmV16MrkTy9s+8DhLPnxn7NiCC8SXYq 6Q+yTL0l4eU3t5xH88SPpYkWGbFZJp2W67fANz03Z7/EgNIB27hJjZdGxZTegk59VOeQ nqFg== Return-Path: From: Adhemerval Zanella To: libc-alpha@sourceware.org Cc: Wilco Dijkstra Subject: [PATCH 6/6] Add generic hp-timing support Date: Fri, 8 Feb 2019 16:39:10 -0200 Message-Id: <20190208183910.30799-6-adhemerval.zanella@linaro.org> In-Reply-To: <20190208183910.30799-1-adhemerval.zanella@linaro.org> References: <20190208183910.30799-1-adhemerval.zanella@linaro.org> From: Wilco Dijkstra 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. --- benchtests/Makefile | 6 ----- benchtests/README | 7 +----- benchtests/bench-timing.h | 44 +++++++------------------------------ sysdeps/generic/hp-timing.h | 25 +++++++++++++-------- 4 files changed, 25 insertions(+), 57 deletions(-) diff --git a/benchtests/Makefile b/benchtests/Makefile index e1907753b4..50cb7cd2e8 100644 --- a/benchtests/Makefile +++ b/benchtests/Makefile @@ -127,17 +127,11 @@ endif CPPFLAGS-nonlib += -DDURATION=$(BENCH_DURATION) -D_ISOMAC -# Use clock_gettime to measure performance of functions. The default is to use -# HP_TIMING if it is available. -ifdef USE_CLOCK_GETTIME -CPPFLAGS-nonlib += -DUSE_CLOCK_GETTIME -else # On x86 processors, use RDTSCP, instead of RDTSC, to measure performance # of functions. All x86 processors since 2010 support RDTSCP instruction. ifdef USE_RDTSCP CPPFLAGS-nonlib += -DUSE_RDTSCP endif -endif DETAILED_OPT := 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 diff --git a/benchtests/bench-timing.h b/benchtests/bench-timing.h index 93fe379f99..e213dec3fd 100644 --- a/benchtests/bench-timing.h +++ b/benchtests/bench-timing.h @@ -18,49 +18,21 @@ #undef attribute_hidden #define attribute_hidden +#define __clock_gettime clock_gettime #include #include -#if HP_TIMING_INLINE && !defined USE_CLOCK_GETTIME -# define GL(x) _##x -# define GLRO(x) _##x +#define GL(x) _##x +#define GLRO(x) _##x typedef hp_timing_t timing_t; -# define TIMING_TYPE "hp_timing" +#define TIMING_TYPE "hp_timing" -# define TIMING_INIT(res) ({ (res) = 1; }) +#define TIMING_INIT(res) ({ (res) = 1; }) -# define TIMING_NOW(var) HP_TIMING_NOW (var) -# define TIMING_DIFF(diff, start, end) HP_TIMING_DIFF ((diff), (start), (end)) -# define TIMING_ACCUM(sum, diff) HP_TIMING_ACCUM_NT ((sum), (diff)) - -#else - -#include -typedef uint64_t timing_t; - -# define TIMING_TYPE "clock_gettime" - -/* Measure the resolution of the clock so we can scale the number of - benchmark iterations by this value. */ -# define TIMING_INIT(res) \ -({ \ - struct timespec start; \ - clock_getres (CLOCK_PROCESS_CPUTIME_ID, &start); \ - (res) = start.tv_nsec; \ -}) - -# define TIMING_NOW(var) \ -({ \ - struct timespec tv; \ - clock_gettime (CLOCK_PROCESS_CPUTIME_ID, &tv); \ - (var) = (uint64_t) (tv.tv_nsec + (uint64_t) 1000000000 * tv.tv_sec); \ -}) - -# define TIMING_DIFF(diff, start, end) (diff) = (end) - (start) -# define TIMING_ACCUM(sum, diff) (sum) += (diff) - -#endif +#define TIMING_NOW(var) HP_TIMING_NOW (var) +#define TIMING_DIFF(diff, start, end) HP_TIMING_DIFF ((diff), (start), (end)) +#define TIMING_ACCUM(sum, diff) HP_TIMING_ACCUM_NT ((sum), (diff)) #define TIMING_PRINT_MEAN(d_total_s, d_iters) \ printf ("\t%g", (d_total_s) / (d_iters)) diff --git a/sysdeps/generic/hp-timing.h b/sysdeps/generic/hp-timing.h index 278998d2c2..2528279558 100644 --- a/sysdeps/generic/hp-timing.h +++ b/sysdeps/generic/hp-timing.h @@ -20,16 +20,23 @@ #ifndef _HP_TIMING_H #define _HP_TIMING_H 1 -/* There are no generic definitions for the times. We could write something - using the `gettimeofday' system call where available but the overhead of - the system call might be too high. */ +#include +#include +#include -/* Provide dummy definitions. */ +/* It should not be used for ld.so. */ #define HP_TIMING_INLINE (0) -typedef int hp_timing_t; -#define HP_TIMING_NOW(var) -#define HP_TIMING_DIFF(Diff, Start, End) -#define HP_TIMING_ACCUM_NT(Sum, Diff) -#define HP_TIMING_PRINT(Buf, Len, Val) + +typedef uint64_t hp_timing_t; + +/* The clock_gettime (CLOCK_MONOTONIC) has unspecified starting time, + nano-second accuracy, and for some architectues is implemented as + vDSO symbol. */ +#define HP_TIMING_NOW(var) \ +({ \ + struct timespec tv; \ + __clock_gettime (CLOCK_MONOTONIC, &tv); \ + (var) = (tv.tv_nsec + UINT64_C(1000000000) * tv.tv_sec); \ +}) #endif /* hp-timing.h */