Messages in this thread Patch in this message | | | From | Anshuman Khandual <> | Subject | [PATCH V9 10/10] arm64/perf: Implement branch records save on PMU IRQ | Date | Wed, 15 Mar 2023 10:44:44 +0530 |
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This modifies armv8pmu_branch_read() to concatenate live entries along with task context stored entries and then process the resultant buffer to create perf branch entry array for perf_sample_data. It follows the same principle like task sched out.
Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> --- arch/arm64/kernel/brbe.c | 75 +++++++++++++++------------------------- 1 file changed, 28 insertions(+), 47 deletions(-)
diff --git a/arch/arm64/kernel/brbe.c b/arch/arm64/kernel/brbe.c index 3dcb4407b92a..652af6668d37 100644 --- a/arch/arm64/kernel/brbe.c +++ b/arch/arm64/kernel/brbe.c @@ -693,41 +693,45 @@ void armv8pmu_branch_reset(void) isb(); } -static bool capture_branch_entry(struct pmu_hw_events *cpuc, - struct perf_event *event, int idx) +static void brbe_regset_branch_entries(struct pmu_hw_events *cpuc, struct perf_event *event, + struct brbe_regset *regset, int idx) { struct perf_branch_entry *entry = &cpuc->branches->branch_entries[idx]; - u64 brbinf = get_brbinf_reg(idx); - - /* - * There are no valid entries anymore on the buffer. - * Abort the branch record processing to save some - * cycles and also reduce the capture/process load - * for the user space as well. - */ - if (brbe_invalid(brbinf)) - return false; + u64 brbinf = regset[idx].brbinf; perf_clear_branch_entry_bitfields(entry); if (brbe_record_is_complete(brbinf)) { - entry->from = get_brbsrc_reg(idx); - entry->to = get_brbtgt_reg(idx); + entry->from = regset[idx].brbsrc; + entry->to = regset[idx].brbtgt; } else if (brbe_record_is_source_only(brbinf)) { - entry->from = get_brbsrc_reg(idx); + entry->from = regset[idx].brbsrc; entry->to = 0; } else if (brbe_record_is_target_only(brbinf)) { entry->from = 0; - entry->to = get_brbtgt_reg(idx); + entry->to = regset[idx].brbtgt; } capture_brbe_flags(entry, event, brbinf); - return true; +} + +static void process_branch_entries(struct pmu_hw_events *cpuc, struct perf_event *event, + struct brbe_regset *regset, int nr_regset) +{ + int idx; + + for (idx = 0; idx < nr_regset; idx++) + brbe_regset_branch_entries(cpuc, event, regset, idx); + + cpuc->branches->branch_stack.nr = nr_regset; + cpuc->branches->branch_stack.hw_idx = -1ULL; } void armv8pmu_branch_read(struct pmu_hw_events *cpuc, struct perf_event *event) { struct brbe_hw_attr *brbe_attr = (struct brbe_hw_attr *)cpuc->percpu_pmu->private; + struct arm64_perf_task_context *task_ctx = event->pmu_ctx->task_ctx_data; + struct brbe_regset live[BRBE_MAX_ENTRIES]; + int nr_live, nr_store; u64 brbfcr, brbcr; - int idx, loop1_idx1, loop1_idx2, loop2_idx1, loop2_idx2, count; brbcr = read_sysreg_s(SYS_BRBCR_EL1); brbfcr = read_sysreg_s(SYS_BRBFCR_EL1); @@ -739,36 +743,13 @@ void armv8pmu_branch_read(struct pmu_hw_events *cpuc, struct perf_event *event) write_sysreg_s(brbfcr | BRBFCR_EL1_PAUSED, SYS_BRBFCR_EL1); isb(); - /* Determine the indices for each loop */ - loop1_idx1 = BRBE_BANK0_IDX_MIN; - if (brbe_attr->brbe_nr <= BRBE_BANK_MAX_ENTRIES) { - loop1_idx2 = brbe_attr->brbe_nr - 1; - loop2_idx1 = BRBE_BANK1_IDX_MIN; - loop2_idx2 = BRBE_BANK0_IDX_MAX; - } else { - loop1_idx2 = BRBE_BANK0_IDX_MAX; - loop2_idx1 = BRBE_BANK1_IDX_MIN; - loop2_idx2 = brbe_attr->brbe_nr - 1; - } - - /* Loop through bank 0 */ - select_brbe_bank(BRBE_BANK_IDX_0); - for (idx = 0, count = loop1_idx1; count <= loop1_idx2; idx++, count++) { - if (!capture_branch_entry(cpuc, event, idx)) - goto skip_bank_1; - } - - /* Loop through bank 1 */ - select_brbe_bank(BRBE_BANK_IDX_1); - for (count = loop2_idx1; count <= loop2_idx2; idx++, count++) { - if (!capture_branch_entry(cpuc, event, idx)) - break; - } - -skip_bank_1: - cpuc->branches->branch_stack.nr = idx; - cpuc->branches->branch_stack.hw_idx = -1ULL; + nr_live = capture_brbe_regset(brbe_attr, live); + nr_store = task_ctx->nr_brbe_records; + nr_store = stitch_stored_live_entries(task_ctx->store, live, nr_store, + nr_live, brbe_attr->brbe_nr); + process_branch_entries(cpuc, event, task_ctx->store, nr_store); process_branch_aborts(cpuc); + task_ctx->nr_brbe_records = 0; /* Unpause the buffer */ write_sysreg_s(brbfcr & ~BRBFCR_EL1_PAUSED, SYS_BRBFCR_EL1); -- 2.25.1
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