| /* |
| american fuzzy lop - free CPU gizmo |
| ----------------------------------- |
| |
| Written and maintained by Michal Zalewski <lcamtuf@google.com> |
| |
| Copyright 2015, 2016 Google Inc. All rights reserved. |
| |
| Licensed under the Apache License, Version 2.0 (the "License"); |
| you may not use this file except in compliance with the License. |
| You may obtain a copy of the License at: |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| This tool provides a fairly accurate measurement of CPU preemption rate. |
| It is meant to complement the quick-and-dirty load average widget shown |
| in the afl-fuzz UI. See docs/parallel_fuzzing.txt for more info. |
| |
| For some work loads, the tool may actually suggest running more instances |
| than you have CPU cores. This can happen if the tested program is spending |
| a portion of its run time waiting for I/O, rather than being 100% |
| CPU-bound. |
| |
| The idea for the getrusage()-based approach comes from Jakub Wilk. |
| |
| */ |
| |
| #define AFL_MAIN |
| #define _GNU_SOURCE |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <sched.h> |
| |
| #include <sys/time.h> |
| #include <sys/times.h> |
| #include <sys/resource.h> |
| #include <sys/wait.h> |
| |
| #include "types.h" |
| #include "debug.h" |
| |
| #ifdef __linux__ |
| # define HAVE_AFFINITY 1 |
| #endif /* __linux__ */ |
| |
| |
| /* Get unix time in microseconds. */ |
| |
| static u64 get_cur_time_us(void) { |
| |
| struct timeval tv; |
| struct timezone tz; |
| |
| gettimeofday(&tv, &tz); |
| |
| return (tv.tv_sec * 1000000ULL) + tv.tv_usec; |
| |
| } |
| |
| |
| /* Get CPU usage in microseconds. */ |
| |
| static u64 get_cpu_usage_us(void) { |
| |
| struct rusage u; |
| |
| getrusage(RUSAGE_SELF, &u); |
| |
| return (u.ru_utime.tv_sec * 1000000ULL) + u.ru_utime.tv_usec + |
| (u.ru_stime.tv_sec * 1000000ULL) + u.ru_stime.tv_usec; |
| |
| } |
| |
| |
| /* Measure preemption rate. */ |
| |
| static u32 measure_preemption(u32 target_ms) { |
| |
| static volatile u32 v1, v2; |
| |
| u64 st_t, en_t, st_c, en_c, real_delta, slice_delta; |
| s32 loop_repeats = 0; |
| |
| st_t = get_cur_time_us(); |
| st_c = get_cpu_usage_us(); |
| |
| repeat_loop: |
| |
| v1 = CTEST_BUSY_CYCLES; |
| |
| while (v1--) v2++; |
| sched_yield(); |
| |
| en_t = get_cur_time_us(); |
| |
| if (en_t - st_t < target_ms * 1000) { |
| loop_repeats++; |
| goto repeat_loop; |
| } |
| |
| /* Let's see what percentage of this time we actually had a chance to |
| run, and how much time was spent in the penalty box. */ |
| |
| en_c = get_cpu_usage_us(); |
| |
| real_delta = (en_t - st_t) / 1000; |
| slice_delta = (en_c - st_c) / 1000; |
| |
| return real_delta * 100 / slice_delta; |
| |
| } |
| |
| |
| /* Do the benchmark thing. */ |
| |
| int main(int argc, char** argv) { |
| |
| #ifdef HAVE_AFFINITY |
| |
| u32 cpu_cnt = sysconf(_SC_NPROCESSORS_ONLN), |
| idle_cpus = 0, maybe_cpus = 0, i; |
| |
| SAYF(cCYA "afl-gotcpu " cBRI VERSION cRST " by <lcamtuf@google.com>\n"); |
| |
| ACTF("Measuring per-core preemption rate (this will take %0.02f sec)...", |
| ((double)CTEST_CORE_TRG_MS) / 1000); |
| |
| for (i = 0; i < cpu_cnt; i++) { |
| |
| s32 fr = fork(); |
| |
| if (fr < 0) PFATAL("fork failed"); |
| |
| if (!fr) { |
| |
| cpu_set_t c; |
| u32 util_perc; |
| |
| CPU_ZERO(&c); |
| CPU_SET(i, &c); |
| |
| if (sched_setaffinity(0, sizeof(c), &c)) |
| PFATAL("sched_setaffinity failed"); |
| |
| util_perc = measure_preemption(CTEST_CORE_TRG_MS); |
| |
| if (util_perc < 110) { |
| |
| SAYF(" Core #%u: " cLGN "AVAILABLE\n" cRST, i); |
| exit(0); |
| |
| } else if (util_perc < 250) { |
| |
| SAYF(" Core #%u: " cYEL "CAUTION " cRST "(%u%%)\n", i, util_perc); |
| exit(1); |
| |
| } |
| |
| SAYF(" Core #%u: " cLRD "OVERBOOKED " cRST "(%u%%)\n" cRST, i, |
| util_perc); |
| exit(2); |
| |
| } |
| |
| } |
| |
| for (i = 0; i < cpu_cnt; i++) { |
| |
| int ret; |
| if (waitpid(-1, &ret, 0) < 0) PFATAL("waitpid failed"); |
| |
| if (WEXITSTATUS(ret) == 0) idle_cpus++; |
| if (WEXITSTATUS(ret) <= 1) maybe_cpus++; |
| |
| } |
| |
| SAYF(cGRA "\n>>> "); |
| |
| if (idle_cpus) { |
| |
| if (maybe_cpus == idle_cpus) { |
| |
| SAYF(cLGN "PASS: " cRST "You can run more processes on %u core%s.", |
| idle_cpus, idle_cpus > 1 ? "s" : ""); |
| |
| } else { |
| |
| SAYF(cLGN "PASS: " cRST "You can run more processes on %u to %u core%s.", |
| idle_cpus, maybe_cpus, maybe_cpus > 1 ? "s" : ""); |
| |
| } |
| |
| SAYF(cGRA " <<<" cRST "\n\n"); |
| return 0; |
| |
| } |
| |
| if (maybe_cpus) { |
| |
| SAYF(cYEL "CAUTION: " cRST "You may still have %u core%s available.", |
| maybe_cpus, maybe_cpus > 1 ? "s" : ""); |
| SAYF(cGRA " <<<" cRST "\n\n"); |
| return 1; |
| |
| } |
| |
| SAYF(cLRD "FAIL: " cRST "All cores are overbooked."); |
| SAYF(cGRA " <<<" cRST "\n\n"); |
| return 2; |
| |
| #else |
| |
| u32 util_perc; |
| |
| SAYF(cCYA "afl-gotcpu " cBRI VERSION cRST " by <lcamtuf@google.com>\n"); |
| |
| /* Run a busy loop for CTEST_TARGET_MS. */ |
| |
| ACTF("Measuring gross preemption rate (this will take %0.02f sec)...", |
| ((double)CTEST_TARGET_MS) / 1000); |
| |
| util_perc = measure_preemption(CTEST_TARGET_MS); |
| |
| /* Deliver the final verdict. */ |
| |
| SAYF(cGRA "\n>>> "); |
| |
| if (util_perc < 105) { |
| |
| SAYF(cLGN "PASS: " cRST "You can probably run additional processes."); |
| |
| } else if (util_perc < 130) { |
| |
| SAYF(cYEL "CAUTION: " cRST "Your CPU may be somewhat overbooked (%u%%).", |
| util_perc); |
| |
| } else { |
| |
| SAYF(cLRD "FAIL: " cRST "Your CPU is overbooked (%u%%).", util_perc); |
| |
| } |
| |
| SAYF(cGRA " <<<" cRST "\n\n"); |
| |
| return (util_perc > 105) + (util_perc > 130); |
| |
| #endif /* ^HAVE_AFFINITY */ |
| |
| } |