Messages in this thread Patch in this message | | | From | kan.liang@linux ... | Subject | [PATCH V3 10/17] perf tools: Save previous sample for LBR stitching approach | Date | Fri, 13 Mar 2020 11:33:12 -0700 |
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From: Kan Liang <kan.liang@linux.intel.com>
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.
Reviewed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> --- tools/perf/util/machine.c | 23 +++++++++++++++++++++++ tools/perf/util/thread.c | 1 + tools/perf/util/thread.h | 16 ++++++++++++++++ 3 files changed, 40 insertions(+)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index f1661dd3ca69..d91e11bfc8ca 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -2261,6 +2261,21 @@ 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 = calloc(1, sizeof(struct 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: @@ -2277,6 +2292,7 @@ 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; @@ -2289,6 +2305,13 @@ 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..5fe239bd8f17 100644 --- a/tools/perf/util/thread.h +++ b/tools/perf/util/thread.h @@ -13,6 +13,7 @@ #include <strlist.h> #include <intlist.h> #include "rwsem.h" +#include "event.h" struct addr_location; struct map; @@ -20,6 +21,10 @@ 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 +54,7 @@ struct thread { /* LBR call stack stitch */ bool lbr_stitch_enable; + struct lbr_stitch *lbr_stitch; }; struct machine; @@ -145,4 +151,14 @@ static inline bool thread__is_filtered(struct thread *thread) return false; } +static inline void thread__free_stitch_list(struct thread *thread) +{ + struct lbr_stitch *lbr_stitch = thread->lbr_stitch; + + if (!lbr_stitch) + return; + + free(thread->lbr_stitch); +} + #endif /* __PERF_THREAD_H */ -- 2.17.1
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