Messages in this thread Patch in this message |  | | From | Wang Nan <> | Subject | [PATCH 49/55] perf tools: Record fd into perf_mmap | Date | Fri, 19 Feb 2016 11:44:37 +0000 |
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Add a fd field into perf_mmap so perf can backtrack the fd from mmap. This feature will be used to toggle overwrite ring buffers.
Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: He Kuang <hekuang@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com --- tools/perf/util/evlist.c | 15 +++++++++++++-- tools/perf/util/evlist.h | 1 + 2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 36dd305..bd2393a 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -868,6 +868,7 @@ 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].fd = -1; atomic_set(&evlist->mmap[idx].refcnt, 0); } auxtrace_mmap__munmap(&evlist->mmap[idx].auxtrace_mmap); @@ -903,7 +904,7 @@ void perf_evlist__munmap(struct perf_evlist *evlist) static int perf_evlist__alloc_mmap(struct perf_evlist *evlist) { - int total_mmaps; + int total_mmaps, i; evlist->nr_mmaps = cpu_map__nr(evlist->cpus); if (cpu_map__empty(evlist->cpus)) @@ -914,7 +915,12 @@ static int perf_evlist__alloc_mmap(struct perf_evlist *evlist) return -EINVAL; evlist->mmap = zalloc(total_mmaps * sizeof(struct perf_mmap)); - return evlist->mmap != NULL ? 0 : -ENOMEM; + if (!evlist->mmap) + return -ENOMEM; + + for (i = 0; i < total_mmaps; i++) + evlist->mmap[i].fd = -1; + return 0; } struct mmap_params { @@ -934,6 +940,10 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx, if (!perf_evlist__channel_check(evlist, channel, RDONLY)) prot |= PROT_WRITE; + if (evlist->mmap[idx].fd >= 0) { + pr_err("idx %d already mapped\n", idx); + return -1; + } /* * The last one will be done at perf_evlist__mmap_consume(), so that we * make sure we don't prevent tools from consuming every last event in @@ -958,6 +968,7 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx, evlist->mmap[idx].base = NULL; return -1; } + evlist->mmap[idx].fd = fd; if (auxtrace_mmap__mmap(&evlist->mmap[idx].auxtrace_mmap, &mp->auxtrace_mp, evlist->mmap[idx].base, fd)) diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 321224c..bc6d787 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -35,6 +35,7 @@ enum perf_evlist_mmap_flag { struct perf_mmap { void *base; int mask; + int fd; atomic_t refcnt; u64 prev; struct auxtrace_mmap auxtrace_mmap; -- 1.8.3.4
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