From db25bf98a3861225bc0b2138cf665097141c72ee Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 18 Oct 2019 11:48:57 -0300 Subject: [PATCH] perf trace: Honour --max-events in processing syscalls:sys_enter_* MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We were doing this only at the sys_exit syscall tracepoint, as for strace-like we count the pair of sys_enter and sys_exit as one event, but when asking specifically for a the syscalls:sys_enter_NAME tracepoint we need to count each of those as an event. I.e. things like: # perf trace --max-events=4 -e syscalls:sys_enter_lseek 0.000 pool/2242 syscalls:sys_enter_lseek(fd: 14, offset: 0, whence: CUR) 0.034 pool/2242 syscalls:sys_enter_lseek(fd: 15, offset: 0, whence: CUR) 0.051 pool/2242 syscalls:sys_enter_lseek(fd: 16, offset: 0, whence: CUR) 2307.900 sshd/30800 syscalls:sys_enter_lseek(fd: 3, offset: 9032, whence: SET) # Were going on forever, since we only had sys_enter events. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Luis Cláudio Gonçalves Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-0ob1dky1a9ijlfrfhxyl40wr@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 0294b17ed510..1aaf7b28eec4 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -2727,12 +2727,6 @@ static int trace__event_handler(struct trace *trace, struct evsel *evsel, } else { trace__fprintf_tp_fields(trace, evsel, sample, thread, NULL, 0); } - ++trace->nr_events_printed; - - if (evsel->max_events != ULONG_MAX && ++evsel->nr_events_printed == evsel->max_events) { - evsel__disable(evsel); - evsel__close(evsel); - } } } @@ -2743,6 +2737,13 @@ static int trace__event_handler(struct trace *trace, struct evsel *evsel, trace__fprintf_callchain(trace, sample); else if (callchain_ret < 0) pr_err("Problem processing %s callchain, skipping...\n", perf_evsel__name(evsel)); + + ++trace->nr_events_printed; + + if (evsel->max_events != ULONG_MAX && ++evsel->nr_events_printed == evsel->max_events) { + evsel__disable(evsel); + evsel__close(evsel); + } out: thread__put(thread); return 0;