Commit-ID: da9000ae35027fb7305b8cad0b37df71937ad578 Gitweb: https://git.kernel.org/tip/da9000ae35027fb7305b8cad0b37df71937ad578 Author: Adrian Hunter <adrian.hun...@intel.com> AuthorDate: Tue, 4 Jun 2019 16:00:08 +0300 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Mon, 10 Jun 2019 16:20:12 -0300
perf intel-pt: Add support for lookahead Implement the lookahead callback to let the decoder access subsequent buffers. intel_pt_lookahead() manages the buffer lifetime and calls the decoder for each buffer until the decoder returns a non-zero value. Signed-off-by: Adrian Hunter <adrian.hun...@intel.com> Cc: Jin Yao <yao....@linux.intel.com> Cc: Jiri Olsa <jo...@redhat.com> Link: http://lkml.kernel.org/r/20190604130017.31207-11-adrian.hun...@intel.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/intel-pt.c | 59 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 58 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c index 4a61c73c9711..3e3a01318b76 100644 --- a/tools/perf/util/intel-pt.c +++ b/tools/perf/util/intel-pt.c @@ -278,7 +278,63 @@ static int intel_pt_get_buffer(struct intel_pt_queue *ptq, return 0; } -/* This function assumes data is processed sequentially only */ +/* Do not drop buffers with references - refer intel_pt_get_trace() */ +static void intel_pt_lookahead_drop_buffer(struct intel_pt_queue *ptq, + struct auxtrace_buffer *buffer) +{ + if (!buffer || buffer == ptq->buffer || buffer == ptq->old_buffer) + return; + + auxtrace_buffer__drop_data(buffer); +} + +/* Must be serialized with respect to intel_pt_get_trace() */ +static int intel_pt_lookahead(void *data, intel_pt_lookahead_cb_t cb, + void *cb_data) +{ + struct intel_pt_queue *ptq = data; + struct auxtrace_buffer *buffer = ptq->buffer; + struct auxtrace_buffer *old_buffer = ptq->old_buffer; + struct auxtrace_queue *queue; + int err = 0; + + queue = &ptq->pt->queues.queue_array[ptq->queue_nr]; + + while (1) { + struct intel_pt_buffer b = { .len = 0 }; + + buffer = auxtrace_buffer__next(queue, buffer); + if (!buffer) + break; + + err = intel_pt_get_buffer(ptq, buffer, old_buffer, &b); + if (err) + break; + + if (b.len) { + intel_pt_lookahead_drop_buffer(ptq, old_buffer); + old_buffer = buffer; + } else { + intel_pt_lookahead_drop_buffer(ptq, buffer); + continue; + } + + err = cb(&b, cb_data); + if (err) + break; + } + + if (buffer != old_buffer) + intel_pt_lookahead_drop_buffer(ptq, buffer); + intel_pt_lookahead_drop_buffer(ptq, old_buffer); + + return err; +} + +/* + * This function assumes data is processed sequentially only. + * Must be serialized with respect to intel_pt_lookahead() + */ static int intel_pt_get_trace(struct intel_pt_buffer *b, void *data) { struct intel_pt_queue *ptq = data; @@ -827,6 +883,7 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt, params.get_trace = intel_pt_get_trace; params.walk_insn = intel_pt_walk_next_insn; + params.lookahead = intel_pt_lookahead; params.data = ptq; params.return_compression = intel_pt_return_compression(pt); params.branch_enable = intel_pt_branch_enable(pt);
