#include "util.h" #include "../perf.h" #include #include "evsel.h" #include "cgroup.h" #include "evlist.h" int nr_cgroups; static int cgroupfs_find_mountpoint(char *buf, size_t maxlen) { FILE *fp; char mountpoint[PATH_MAX + 1], tokens[PATH_MAX + 1], type[PATH_MAX + 1]; char *token, *saved_ptr = NULL; int found = 0; fp = fopen("/proc/mounts", "r"); if (!fp) return -1; /* * in order to handle split hierarchy, we need to scan /proc/mounts * and inspect every cgroupfs mount point to find one that has * perf_event subsystem */ while (fscanf(fp, "%*s %"STR(PATH_MAX)"s %"STR(PATH_MAX)"s %" STR(PATH_MAX)"s %*d %*d\n", mountpoint, type, tokens) == 3) { if (!strcmp(type, "cgroup")) { token = strtok_r(tokens, ",", &saved_ptr); while (token != NULL) { if (!strcmp(token, "perf_event")) { found = 1; break; } token = strtok_r(NULL, ",", &saved_ptr); } } if (found) break; } fclose(fp); if (!found) return -1; if (strlen(mountpoint) < maxlen) { strcpy(buf, mountpoint); return 0; } return -1; } static int open_cgroup(char *name) { char path[PATH_MAX + 1]; char mnt[PATH_MAX + 1]; int fd; if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1)) return -1; snprintf(path, PATH_MAX, "%s/%s", mnt, name); fd = open(path, O_RDONLY); if (fd == -1) fprintf(stderr, "no access to cgroup %s\n", path); return fd; } static int add_cgroup(struct perf_evlist *evlist, char *str) { struct perf_evsel *counter; struct cgroup_sel *cgrp = NULL; int n; /* * check if cgrp is already defined, if so we reuse it */ evlist__for_each_entry(evlist, counter) { cgrp = counter->cgrp; if (!cgrp) continue; if (!strcmp(cgrp->name, str)) break; cgrp = NULL; } if (!cgrp) { cgrp = zalloc(sizeof(*cgrp)); if (!cgrp) return -1; cgrp->name = str; cgrp->fd = open_cgroup(str); if (cgrp->fd == -1) { free(cgrp); return -1; } } /* * find corresponding event * if add cgroup N, then need to find event N */ n = 0; evlist__for_each_entry(evlist, counter) { if (n == nr_cgroups) goto found; n++; } if (atomic_read(&cgrp->refcnt) == 0) free(cgrp); return -1; found: atomic_inc(&cgrp->refcnt); counter->cgrp = cgrp; return 0; } void close_cgroup(struct cgroup_sel *cgrp) { if (cgrp && atomic_dec_and_test(&cgrp->refcnt)) { close(cgrp->fd); zfree(&cgrp->name); free(cgrp); } } int parse_cgroups(const struct option *opt __maybe_unused, const char *str, int unset __maybe_unused) { struct perf_evlist *evlist = *(struct perf_evlist **)opt->value; const char *p, *e, *eos = str + strlen(str); char *s; int ret; if (list_empty(&evlist->entries)) { fprintf(stderr, "must define events before cgroups\n"); return -1; } for (;;) { p = strchr(str, ','); e = p ? p : eos; /* allow empty cgroups, i.e., skip */ if (e - str) { /* termination added */ s = strndup(str, e - str); if (!s) return -1; ret = add_cgroup(evlist, s); if (ret) { free(s); return -1; } } /* nr_cgroups is increased een for empty cgroups */ nr_cgroups++; if (!p) break; str = p+1; } return 0; } ls/perf/util/cgroup.h
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authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-30 13:18:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-30 13:18:12 -0800
commit751321b3dd5040dc5be19bd23f985e80c914621a (patch)
tree967928e24b38dc7fed918f932bb1b243af42bf7f /tools/perf/util/cgroup.h
parent566cf877a1fcb6d6dc0126b076aad062054c2637 (diff)
parent586655d278ba08af7b198b93217746f9a506ee8a (diff)
Merge tag 'rtc-4.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC fix from Alexandre Belloni: "A single fix for this cycle. It is worth taking it for 4.10 so that distributions will not have CONFIG_RTC_DRV_JZ4740 switching from m to y in their config. Summary: - Allow jz4740 to build as a module again by using kernel_halt()" * tag 'rtc-4.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: rtc: jz4740: make the driver buildable as a module again
Diffstat (limited to 'tools/perf/util/cgroup.h')