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fb7d0b3cef
GCC 4.6.0 in Fedora rawhide turned up some compile errors in tools/perf due to the -Werror=unused-but-set-variable flag. I've gone through and annotated some of the assignments that had side effects (ie: return value from a function) with the __used annotation, and in some cases, just removed unused code. In a few cases, we were assigning something useful, but not using it in later parts of the function. kyle@dreadnought:~/src% gcc --version gcc (GCC) 4.6.0 20110122 (Red Hat 4.6.0-0.3) Cc: Ingo Molnar <mingo@redhat.com> LKML-Reference: <20110124161304.GK27353@bombadil.infradead.org> Signed-off-by: Kyle McMartin <kyle@redhat.com> [ committer note: Fixed up the annotation fixes, as that code moved recently ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
128 lines
2.7 KiB
C
128 lines
2.7 KiB
C
/*
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*
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* sched-pipe.c
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*
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* pipe: Benchmark for pipe()
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*
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* Based on pipe-test-1m.c by Ingo Molnar <mingo@redhat.com>
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* http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
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* Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
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*
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*/
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#include "../perf.h"
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#include "../util/util.h"
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#include "../util/parse-options.h"
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#include "../builtin.h"
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#include "bench.h"
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#include <unistd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <signal.h>
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#include <sys/wait.h>
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#include <linux/unistd.h>
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#include <string.h>
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#include <errno.h>
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#include <assert.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#define LOOPS_DEFAULT 1000000
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static int loops = LOOPS_DEFAULT;
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static const struct option options[] = {
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OPT_INTEGER('l', "loop", &loops,
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"Specify number of loops"),
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OPT_END()
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};
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static const char * const bench_sched_pipe_usage[] = {
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"perf bench sched pipe <options>",
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NULL
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};
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int bench_sched_pipe(int argc, const char **argv,
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const char *prefix __used)
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{
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int pipe_1[2], pipe_2[2];
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int m = 0, i;
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struct timeval start, stop, diff;
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unsigned long long result_usec = 0;
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/*
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* why does "ret" exist?
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* discarding returned value of read(), write()
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* causes error in building environment for perf
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*/
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int __used ret, wait_stat;
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pid_t pid, retpid;
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argc = parse_options(argc, argv, options,
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bench_sched_pipe_usage, 0);
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assert(!pipe(pipe_1));
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assert(!pipe(pipe_2));
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pid = fork();
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assert(pid >= 0);
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gettimeofday(&start, NULL);
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if (!pid) {
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for (i = 0; i < loops; i++) {
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ret = read(pipe_1[0], &m, sizeof(int));
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ret = write(pipe_2[1], &m, sizeof(int));
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}
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} else {
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for (i = 0; i < loops; i++) {
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ret = write(pipe_1[1], &m, sizeof(int));
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ret = read(pipe_2[0], &m, sizeof(int));
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}
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}
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gettimeofday(&stop, NULL);
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timersub(&stop, &start, &diff);
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if (pid) {
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retpid = waitpid(pid, &wait_stat, 0);
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assert((retpid == pid) && WIFEXITED(wait_stat));
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} else {
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exit(0);
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}
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switch (bench_format) {
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case BENCH_FORMAT_DEFAULT:
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printf("# Executed %d pipe operations between two tasks\n\n",
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loops);
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result_usec = diff.tv_sec * 1000000;
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result_usec += diff.tv_usec;
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printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
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diff.tv_sec,
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(unsigned long) (diff.tv_usec/1000));
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printf(" %14lf usecs/op\n",
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(double)result_usec / (double)loops);
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printf(" %14d ops/sec\n",
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(int)((double)loops /
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((double)result_usec / (double)1000000)));
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break;
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case BENCH_FORMAT_SIMPLE:
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printf("%lu.%03lu\n",
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diff.tv_sec,
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(unsigned long) (diff.tv_usec / 1000));
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break;
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default:
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/* reaching here is something disaster */
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fprintf(stderr, "Unknown format:%d\n", bench_format);
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exit(1);
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break;
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}
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return 0;
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}
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