From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 53/60] perf thread: Save previous sample for LBR stitching approach Date: Mon, 20 Apr 2020 08:53:09 -0300 Message-ID: <20200420115316.18781-54-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200420115316.18781-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Kan Liang , Andi Kleen , Jiri Olsa , Adrian Hunter , Alexey Budankov , Mathieu Poirier , Michael Ellerman , Pavel Gerasimov , Peter Zijlstra , Ravi Bangoria , Stephane Eranian , Vitaly Slobodskoy , Arnaldo Carvalho de Melo List-Id: linux-perf-users.vger.kernel.org From: Kan Liang To retrieve the overwritten LBRs from previous sample for LBR stitching approach, perf has to save the previous sample. Only allocate the struct lbr_stitch once, when LBR stitching approach is enabled and kernel supports hw_idx. Signed-off-by: Kan Liang Reviewed-by: Andi Kleen Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexey Budankov Cc: Mathieu Poirier Cc: Michael Ellerman Cc: Namhyung Kim Cc: Pavel Gerasimov Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Stephane Eranian Cc: Vitaly Slobodskoy Link: http://lore.kernel.org/lkml/20200319202517.23423-11-kan.liang@linux.intel.com [ Use zalloc()/zfree() for thread->lbr_stitch ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/machine.c | 23 +++++++++++++++++++++++ tools/perf/util/thread.c | 1 + tools/perf/util/thread.h | 12 ++++++++++++ 3 files changed, 36 insertions(+) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index f9d69fce584a..a54ca09a1d00 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -2292,6 +2292,21 @@ static int lbr_callchain_add_lbr_ip(struct thread *thread, return 0; } +static bool alloc_lbr_stitch(struct thread *thread) +{ + if (thread->lbr_stitch) + return true; + + thread->lbr_stitch = zalloc(sizeof(*thread->lbr_stitch)); + if (!thread->lbr_stitch) + goto err; + +err: + pr_warning("Failed to allocate space for stitched LBRs. Disable LBR stitch\n"); + thread->lbr_stitch_enable = false; + return false; +} + /* * Recolve LBR callstack chain sample * Return: @@ -2308,6 +2323,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread, { struct ip_callchain *chain = sample->callchain; int chain_nr = min(max_stack, (int)chain->nr), i; + struct lbr_stitch *lbr_stitch; u64 branch_from = 0; int err; @@ -2320,6 +2336,13 @@ static int resolve_lbr_callchain_sample(struct thread *thread, if (i == chain_nr) return 0; + if (thread->lbr_stitch_enable && !sample->no_hw_idx && + alloc_lbr_stitch(thread)) { + lbr_stitch = thread->lbr_stitch; + + memcpy(&lbr_stitch->prev_sample, sample, sizeof(*sample)); + } + if (callchain_param.order == ORDER_CALLEE) { /* Add kernel ip */ err = lbr_callchain_add_kernel_ip(thread, cursor, sample, diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c index 1f080db23615..8d0da260c84c 100644 --- a/tools/perf/util/thread.c +++ b/tools/perf/util/thread.c @@ -111,6 +111,7 @@ void thread__delete(struct thread *thread) exit_rwsem(&thread->namespaces_lock); exit_rwsem(&thread->comm_lock); + thread__free_stitch_list(thread); free(thread); } diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h index 95294050cff2..34eb61cee6a4 100644 --- a/tools/perf/util/thread.h +++ b/tools/perf/util/thread.h @@ -5,6 +5,7 @@ #include #include #include +#include #include #include #include @@ -13,6 +14,7 @@ #include #include #include "rwsem.h" +#include "event.h" struct addr_location; struct map; @@ -20,6 +22,10 @@ struct perf_record_namespaces; struct thread_stack; struct unwind_libunwind_ops; +struct lbr_stitch { + struct perf_sample prev_sample; +}; + struct thread { union { struct rb_node rb_node; @@ -49,6 +55,7 @@ struct thread { /* LBR call stack stitch */ bool lbr_stitch_enable; + struct lbr_stitch *lbr_stitch; }; struct machine; @@ -145,4 +152,9 @@ static inline bool thread__is_filtered(struct thread *thread) return false; } +static inline void thread__free_stitch_list(struct thread *thread) +{ + zfree(&thread->lbr_stitch); +} + #endif /* __PERF_THREAD_H */ -- 2.21.1