From d20aff1512f013fab79b8740427b7574569a9a2e Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Tue, 1 Sep 2020 12:37:57 +0300 Subject: perf record: Add 'snapshot' control command Add 'snapshot' control command to create an AUX area tracing snapshot the same as if sending SIGUSR2. The advantage of the FIFO is that access is governed by access to the FIFO. Example: $ mkfifo perf.control $ mkfifo perf.ack $ cat perf.ack & [1] 15235 $ sudo ~/bin/perf record --control fifo:perf.control,perf.ack -S -e intel_pt//u -- sleep 60 & [2] 15243 $ ps -e | grep perf 15244 pts/1 00:00:00 perf $ kill -USR2 15244 bash: kill: (15244) - Operation not permitted $ echo snapshot > perf.control ack $ Signed-off-by: Adrian Hunter Acked-by: Alexey Budankov Acked-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Andi Kleen Cc: Namhyung Kim Link: http://lore.kernel.org/lkml/20200901093758.32293-6-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evlist.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'tools/perf/util/evlist.c') diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 00593e5f2a9d..e72ff7e78dec 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1887,13 +1887,17 @@ static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd, } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG, (sizeof(EVLIST_CTL_CMD_DISABLE_TAG)-1))) { *cmd = EVLIST_CTL_CMD_DISABLE; + } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_SNAPSHOT_TAG, + (sizeof(EVLIST_CTL_CMD_SNAPSHOT_TAG)-1))) { + *cmd = EVLIST_CTL_CMD_SNAPSHOT; + pr_debug("is snapshot\n"); } } return bytes_read ? (int)bytes_read : err; } -static int evlist__ctlfd_ack(struct evlist *evlist) +int evlist__ctlfd_ack(struct evlist *evlist) { int err; @@ -1929,13 +1933,16 @@ int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd) case EVLIST_CTL_CMD_DISABLE: evlist__disable(evlist); break; + case EVLIST_CTL_CMD_SNAPSHOT: + break; case EVLIST_CTL_CMD_ACK: case EVLIST_CTL_CMD_UNSUPPORTED: default: pr_debug("ctlfd: unsupported %d\n", *cmd); break; } - if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED)) + if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED || + *cmd == EVLIST_CTL_CMD_SNAPSHOT)) evlist__ctlfd_ack(evlist); } } -- cgit v1.2.3