From: Arnaldo Carvalho de Melo <a...@redhat.com> We need to know how many fds are using a perf mmap via PERF_EVENT_IOC_SET_OUTPUT, so that we can know when to ditch an mmap, refcount it.
Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: Borislav Petkov <b...@suse.de> Cc: Corey Ashford <cjash...@linux.vnet.ibm.com> Cc: David Ahern <dsah...@gmail.com> Cc: Frederic Weisbecker <fweis...@gmail.com> Cc: Ingo Molnar <mi...@kernel.org> Cc: Jean Pihet <jean.pi...@linaro.org> Cc: Jiri Olsa <jo...@kernel.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> Link: http://lkml.kernel.org/r/20140908153824.gg2...@kernel.org Link: http://lkml.kernel.org/n/tip-9ymfcxmk52sb7u1g0i3ai...@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/evlist.c | 21 ++++++++++++++++++++- tools/perf/util/evlist.h | 6 ++++++ 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 477ede5367ee..662057a44126 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -664,6 +664,7 @@ static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx) if (evlist->mmap[idx].base != NULL) { munmap(evlist->mmap[idx].base, evlist->mmap_len); evlist->mmap[idx].base = NULL; + evlist->mmap[idx].nfds = 0; } } @@ -697,6 +698,7 @@ struct mmap_params { static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx, struct mmap_params *mp, int fd) { + evlist->mmap[idx].nfds = 1; evlist->mmap[idx].prev = 0; evlist->mmap[idx].mask = mp->mask; evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, mp->prot, @@ -711,6 +713,19 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx, return 0; } +static void perf_evlist__mmap_get(struct perf_evlist *evlist, int idx) +{ + ++evlist->mmap[idx].nfds; +} + +static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx) +{ + BUG_ON(evlist->mmap[idx].nfds == 0); + + if (--evlist->mmap[idx].nfds == 0) + __perf_evlist__munmap(evlist, idx); +} + static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx, struct mmap_params *mp, int cpu, int thread, int *output) @@ -732,10 +747,14 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx, } else { if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0) return -1; + + perf_evlist__mmap_get(evlist, idx); } - if (perf_evlist__add_pollfd(evlist, fd) < 0) + if (perf_evlist__add_pollfd(evlist, fd) < 0) { + perf_evlist__mmap_put(evlist, idx); return -1; + } if ((evsel->attr.read_format & PERF_FORMAT_ID) && perf_evlist__id_add_fd(evlist, evsel, cpu, thread, fd) < 0) diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index fc013704d903..19bbe0410827 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -18,9 +18,15 @@ struct record_opts; #define PERF_EVLIST__HLIST_BITS 8 #define PERF_EVLIST__HLIST_SIZE (1 << PERF_EVLIST__HLIST_BITS) +/** + * struct perf_mmap - perf's ring buffer mmap details + * + * @nfds - file descriptors pointing here via PERF_EVENT_IOC_SET_OUTPUT + */ struct perf_mmap { void *base; int mask; + int nfds; unsigned int prev; char event_copy[PERF_SAMPLE_MAX_SIZE]; }; -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
