#include #include "util.h" #include "../perf.h" #include "cloexec.h" #include "asm/bug.h" #include "debug.h" #include #include #include static unsigned long flag = PERF_FLAG_FD_CLOEXEC; int __weak sched_getcpu(void) { #ifdef __NR_getcpu unsigned cpu; int err = syscall(__NR_getcpu, &cpu, NULL, NULL); if (!err) return cpu; #else errno = ENOSYS; #endif return -1; } static int perf_flag_probe(void) { /* use 'safest' configuration as used in perf_evsel__fallback() */ struct perf_event_attr attr = { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_CLOCK, .exclude_kernel = 1, }; int fd; int err; int cpu; pid_t pid = -1; char sbuf[STRERR_BUFSIZE]; cpu = sched_getcpu(); if (cpu < 0) cpu = 0; /* * Using -1 for the pid is a workaround to avoid gratuitous jump label * changes. */ while (1) { /* check cloexec flag */ fd = sys_perf_event_open(&attr, pid, cpu, -1, PERF_FLAG_FD_CLOEXEC); if (fd < 0 && pid == -1 && errno == EACCES) { pid = 0; continue; } break; } err = errno; if (fd >= 0) { close(fd); return 1; } WARN_ONCE(err != EINVAL && err != EBUSY, "perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error %d (%s)\n", err, str_error_r(err, sbuf, sizeof(sbuf))); /* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */ while (1) { fd = sys_perf_event_open(&attr, pid, cpu, -1, 0); if (fd < 0 && pid == -1 && errno == EACCES) { pid = 0; continue; } break; } err = errno; if (fd >= 0) close(fd); if (WARN_ONCE(fd < 0 && err != EBUSY, "perf_event_open(..., 0) failed unexpectedly with error %d (%s)\n", err, str_error_r(err, sbuf, sizeof(sbuf)))) return -1; return 0; } unsigned long perf_event_open_cloexec_flag(void) { static bool probed; if (!probed) { if (perf_flag_probe() <= 0) flag = 0; probed = true; } return flag; } ve' href='/cgit.cgi/linux/net-next.git/commit/tools/perf/tests/attr/README?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>commitdiff
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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-11 10:17:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-11 10:17:39 -0800
commit2e4333c14de06a333783d6812cf3c4998f78b0c8 (patch)
tree368428514d70f34f2261c7f954f241f886d6bb51 /tools/perf/tests/attr/README
parent045169816b31b10faed984b01c390db1b32ee4c1 (diff)
parentba735155b9647b6167fd50276ca0fbfbce4e836c (diff)
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS fixes from Ralf Baechle: "Two more MIPS fixes for 4.9: - RTC: Return -ENODEV so an external RTC will be tried - Fix mask of GPE frequency These two have been tested on Imagination's automated test system and also both received positive reviews on the linux-mips mailing list" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: Lantiq: Fix mask of GPE frequency MIPS: Return -ENODEV from weak implementation of rtc_mips_set_time
Diffstat (limited to 'tools/perf/tests/attr/README')