From bde80c237e49983e2b26dfa9925325a070b71de7 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Wed, 15 Apr 2015 19:44:07 +0530 Subject: [PATCH] ARC: perf: Add some comments/debug stuff Signed-off-by: Vineet Gupta --- arch/arc/include/asm/perf_event.h | 53 ++++++++++++++----------------- arch/arc/kernel/perf_event.c | 18 ++++++++--- 2 files changed, 37 insertions(+), 34 deletions(-) diff --git a/arch/arc/include/asm/perf_event.h b/arch/arc/include/asm/perf_event.h index cbf755e32a03..1c45667c1367 100644 --- a/arch/arc/include/asm/perf_event.h +++ b/arch/arc/include/asm/perf_event.h @@ -57,26 +57,7 @@ struct arc_reg_cc_build { #define PERF_COUNT_ARC_HW_MAX (PERF_COUNT_HW_MAX + 6) /* - * The "generalized" performance events seem to really be a copy - * of the available events on x86 processors; the mapping to ARC - * events is not always possible 1-to-1. Fortunately, there doesn't - * seem to be an exact definition for these events, so we can cheat - * a bit where necessary. - * - * In particular, the following PERF events may behave a bit differently - * compared to other architectures: - * - * PERF_COUNT_HW_CPU_CYCLES - * Cycles not in halted state - * - * PERF_COUNT_HW_REF_CPU_CYCLES - * Reference cycles not in halted state, same as PERF_COUNT_HW_CPU_CYCLES - * for now as we don't do Dynamic Voltage/Frequency Scaling (yet) - * - * PERF_COUNT_HW_BUS_CYCLES - * Unclear what this means, Intel uses 0x013c, which according to - * their datasheet means "unhalted reference cycles". It sounds similar - * to PERF_COUNT_HW_REF_CPU_CYCLES, and we use the same counter for it. + * Some ARC pct quirks: * * PERF_COUNT_HW_STALLED_CYCLES_BACKEND * PERF_COUNT_HW_STALLED_CYCLES_FRONTEND @@ -91,21 +72,35 @@ struct arc_reg_cc_build { * Note that I$ cache misses aren't counted by either of the two! */ +/* + * ARC PCT has hardware conditions with fixed "names" but variable "indexes" + * (based on a specific RTL build) + * Below is the static map between perf generic/arc specific event_id and + * h/w condition names. + * At the time of probe, we loop thru each index and find it's name to + * complete the mapping of perf event_id to h/w index as latter is needed + * to program the counter really + */ static const char * const arc_pmu_ev_hw_map[] = { + /* count cycles */ [PERF_COUNT_HW_CPU_CYCLES] = "crun", [PERF_COUNT_HW_REF_CPU_CYCLES] = "crun", [PERF_COUNT_HW_BUS_CYCLES] = "crun", - [PERF_COUNT_HW_INSTRUCTIONS] = "iall", - [PERF_COUNT_HW_BRANCH_MISSES] = "bpfail", - [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = "ijmp", + [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = "bflush", [PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = "bstall", - [PERF_COUNT_ARC_DCLM] = "dclm", - [PERF_COUNT_ARC_DCSM] = "dcsm", - [PERF_COUNT_ARC_ICM] = "icm", - [PERF_COUNT_ARC_BPOK] = "bpok", - [PERF_COUNT_ARC_EDTLB] = "edtlb", - [PERF_COUNT_ARC_EITLB] = "eitlb", + + /* counts condition */ + [PERF_COUNT_HW_INSTRUCTIONS] = "iall", + [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = "ijmp", + [PERF_COUNT_ARC_BPOK] = "bpok", /* NP-NT, PT-T, PNT-NT */ + [PERF_COUNT_HW_BRANCH_MISSES] = "bpfail", /* NP-T, PT-NT, PNT-T */ + + [PERF_COUNT_ARC_DCLM] = "dclm", /* D-cache Load Miss */ + [PERF_COUNT_ARC_DCSM] = "dcsm", /* D-cache Store Miss */ + [PERF_COUNT_ARC_ICM] = "icm", /* I-cache Miss */ + [PERF_COUNT_ARC_EDTLB] = "edtlb", /* D-TLB Miss */ + [PERF_COUNT_ARC_EITLB] = "eitlb", /* I-TLB Miss */ }; #define C(_x) PERF_COUNT_HW_CACHE_##_x diff --git a/arch/arc/kernel/perf_event.c b/arch/arc/kernel/perf_event.c index 64261c2711b1..181baeed4495 100644 --- a/arch/arc/kernel/perf_event.c +++ b/arch/arc/kernel/perf_event.c @@ -90,6 +90,10 @@ static int arc_pmu_cache_event(u64 config) if (ret == CACHE_OP_UNSUPPORTED) return -ENOENT; + pr_debug("init cache event: type/op/result %d/%d/%d with h/w %d \'%s\'\n", + cache_type, cache_op, cache_result, ret, + arc_pmu_ev_hw_map[ret]); + return ret; } @@ -106,8 +110,9 @@ static int arc_pmu_event_init(struct perf_event *event) if (arc_pmu->ev_hw_idx[event->attr.config] < 0) return -ENOENT; hwc->config = arc_pmu->ev_hw_idx[event->attr.config]; - pr_debug("initializing event %d with cfg %d\n", - (int) event->attr.config, (int) hwc->config); + pr_debug("init event %d with h/w %d \'%s\'\n", + (int) event->attr.config, (int) hwc->config, + arc_pmu_ev_hw_map[event->attr.config]); return 0; case PERF_TYPE_HW_CACHE: ret = arc_pmu_cache_event(event->attr.config); @@ -260,19 +265,22 @@ static int arc_pmu_device_probe(struct platform_device *pdev) arc_pmu->n_counters, arc_pmu->counter_size, cc_bcr.c); cc_name.str[8] = 0; - for (i = 0; i < PERF_COUNT_HW_MAX; i++) + for (i = 0; i < PERF_COUNT_ARC_HW_MAX; i++) arc_pmu->ev_hw_idx[i] = -1; + /* loop thru all available h/w condition indexes */ for (j = 0; j < cc_bcr.c; j++) { write_aux_reg(ARC_REG_CC_INDEX, j); cc_name.indiv.word0 = read_aux_reg(ARC_REG_CC_NAME0); cc_name.indiv.word1 = read_aux_reg(ARC_REG_CC_NAME1); + + /* See if it has been mapped to a perf event_id */ for (i = 0; i < ARRAY_SIZE(arc_pmu_ev_hw_map); i++) { if (arc_pmu_ev_hw_map[i] && !strcmp(arc_pmu_ev_hw_map[i], cc_name.str) && strlen(arc_pmu_ev_hw_map[i])) { - pr_debug("mapping %d to idx %d with name %s\n", - i, j, cc_name.str); + pr_debug("mapping perf event %2d to h/w event \'%8s\' (idx %d)\n", + i, cc_name.str, j); arc_pmu->ev_hw_idx[i] = j; } } -- 2.39.5