From 7c1b16ba0e26e6802d80c99c92529f29bcdcea25 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 10 Jul 2020 18:11:03 +0300 Subject: [PATCH] perf intel-pt: Add support for decoding FUP/TIP only Use the new itrace 'q' option to add support for a mode of decoding that ignores TNT, does not walk object code, but gets the ip from FUP and TIP packets. Example: $ perf record -e intel_pt//u grep -rI pudding drivers [ perf record: Woken up 52 times to write data ] [ perf record: Captured and wrote 57.870 MB perf.data ] $ time perf script --itrace=bi | wc -l 58948289 real 1m23.863s user 1m23.251s sys 0m7.452s $ time perf script --itrace=biq | wc -l 3385694 real 0m4.453s user 0m4.455s sys 0m0.328s Signed-off-by: Adrian Hunter Reviewed-by: Andi Kleen Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/20200710151104.15137-12-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-intel-pt.txt | 31 ++++ .../perf/util/intel-pt-decoder/intel-pt-decoder.c | 167 ++++++++++++++++++++- .../perf/util/intel-pt-decoder/intel-pt-decoder.h | 1 + tools/perf/util/intel-pt.c | 6 +- 4 files changed, 200 insertions(+), 5 deletions(-) diff --git a/tools/perf/Documentation/perf-intel-pt.txt b/tools/perf/Documentation/perf-intel-pt.txt index 4666e4a83615..f9fe4a4040ba 100644 --- a/tools/perf/Documentation/perf-intel-pt.txt +++ b/tools/perf/Documentation/perf-intel-pt.txt @@ -825,6 +825,7 @@ The letters are: l synthesize last branch entries (use with i or x) L synthesize last branch entries on existing event records s skip initial number of events + q quicker (less detailed) decoding "Instructions" events look like they were recorded by "perf record -e instructions". @@ -969,6 +970,36 @@ at the beginning. This is useful to ignore initialization code. skips the first million instructions. +The q option changes the way the trace is decoded. The decoding is much faster +but much less detailed. Specifically, with the q option, the decoder does not +decode TNT packets, and does not walk object code, but gets the ip from FUP and +TIP packets. The q option can be used with the b and i options but the period +is not used. The q option decodes more quickly, but is useful only if the +control flow of interest is represented or indicated by FUP, TIP, TIP.PGE, or +TIP.PGD packets (refer below). However the q option could be used to find time +ranges that could then be decoded fully using the --time option. + +What will *not* be decoded with the (single) q option: + + - direct calls and jmps + - conditional branches + - non-branch instructions + +What *will* be decoded with the (single) q option: + + - asynchronous branches such as interrupts + - indirect branches + - function return target address *if* the noretcomp config term (refer + config terms section) was used + - start of (control-flow) tracing + - end of (control-flow) tracing, if it is not out of context + - power events, ptwrite, transaction start and abort + - instruction pointer associated with PSB packets + +Note the q option does not specify what events will be synthesized e.g. the p +option must be used also to show power events. + + dump option ~~~~~~~~~~~ diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c index 7ffcbd6fcd1a..ccb204b1a050 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -55,6 +55,7 @@ enum intel_pt_pkt_state { INTEL_PT_STATE_TIP_PGD, INTEL_PT_STATE_FUP, INTEL_PT_STATE_FUP_NO_TIP, + INTEL_PT_STATE_RESAMPLE, }; static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state) @@ -65,6 +66,7 @@ static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state) case INTEL_PT_STATE_ERR_RESYNC: case INTEL_PT_STATE_IN_SYNC: case INTEL_PT_STATE_TNT_CONT: + case INTEL_PT_STATE_RESAMPLE: return true; case INTEL_PT_STATE_TNT: case INTEL_PT_STATE_TIP: @@ -109,6 +111,8 @@ struct intel_pt_decoder { bool fixup_last_mtc; bool have_last_ip; bool in_psb; + bool hop; + bool hop_psb_fup; enum intel_pt_param_flags flags; uint64_t pos; uint64_t last_ip; @@ -235,6 +239,7 @@ struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params) decoder->data = params->data; decoder->return_compression = params->return_compression; decoder->branch_enable = params->branch_enable; + decoder->hop = params->quick >= 1; decoder->flags = params->flags; @@ -275,6 +280,9 @@ struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params) intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult); intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip); + if (decoder->hop) + intel_pt_log("Hop mode: decoding FUP and TIPs, but not TNT\n"); + return decoder; } @@ -1730,8 +1738,14 @@ static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder) case INTEL_PT_FUP: decoder->pge = true; - if (decoder->packet.count) + if (decoder->packet.count) { intel_pt_set_last_ip(decoder); + if (decoder->hop) { + /* Act on FUP at PSBEND */ + decoder->ip = decoder->last_ip; + decoder->hop_psb_fup = true; + } + } break; case INTEL_PT_MODE_TSX: @@ -1875,6 +1889,118 @@ static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder) } } +static int intel_pt_resample(struct intel_pt_decoder *decoder) +{ + decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; + decoder->state.type = INTEL_PT_INSTRUCTION; + decoder->state.from_ip = decoder->ip; + decoder->state.to_ip = 0; + return 0; +} + +#define HOP_PROCESS 0 +#define HOP_IGNORE 1 +#define HOP_RETURN 2 +#define HOP_AGAIN 3 + +/* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */ +static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err) +{ + switch (decoder->packet.type) { + case INTEL_PT_TNT: + return HOP_IGNORE; + + case INTEL_PT_TIP_PGD: + if (!decoder->packet.count) + return HOP_IGNORE; + intel_pt_set_ip(decoder); + decoder->state.type |= INTEL_PT_TRACE_END; + decoder->state.from_ip = 0; + decoder->state.to_ip = decoder->ip; + return HOP_RETURN; + + case INTEL_PT_TIP: + if (!decoder->packet.count) + return HOP_IGNORE; + intel_pt_set_ip(decoder); + decoder->state.type = INTEL_PT_INSTRUCTION; + decoder->state.from_ip = decoder->ip; + decoder->state.to_ip = 0; + return HOP_RETURN; + + case INTEL_PT_FUP: + if (!decoder->packet.count) + return HOP_IGNORE; + intel_pt_set_ip(decoder); + if (intel_pt_fup_event(decoder)) + return HOP_RETURN; + if (!decoder->branch_enable) + *no_tip = true; + if (*no_tip) { + decoder->state.type = INTEL_PT_INSTRUCTION; + decoder->state.from_ip = decoder->ip; + decoder->state.to_ip = 0; + return HOP_RETURN; + } + *err = intel_pt_walk_fup_tip(decoder); + if (!*err) + decoder->pkt_state = INTEL_PT_STATE_RESAMPLE; + return HOP_RETURN; + + case INTEL_PT_PSB: + decoder->last_ip = 0; + decoder->have_last_ip = true; + decoder->hop_psb_fup = false; + *err = intel_pt_walk_psbend(decoder); + if (*err == -EAGAIN) + return HOP_AGAIN; + if (*err) + return HOP_RETURN; + if (decoder->hop_psb_fup) { + decoder->hop_psb_fup = false; + decoder->state.type = INTEL_PT_INSTRUCTION; + decoder->state.from_ip = decoder->ip; + decoder->state.to_ip = 0; + return HOP_RETURN; + } + if (decoder->cbr != decoder->cbr_seen) { + decoder->state.type = 0; + return HOP_RETURN; + } + return HOP_IGNORE; + + case INTEL_PT_BAD: + case INTEL_PT_PAD: + case INTEL_PT_TIP_PGE: + case INTEL_PT_TSC: + case INTEL_PT_TMA: + case INTEL_PT_MODE_EXEC: + case INTEL_PT_MODE_TSX: + case INTEL_PT_MTC: + case INTEL_PT_CYC: + case INTEL_PT_VMCS: + case INTEL_PT_PSBEND: + case INTEL_PT_CBR: + case INTEL_PT_TRACESTOP: + case INTEL_PT_PIP: + case INTEL_PT_OVF: + case INTEL_PT_MNT: + case INTEL_PT_PTWRITE: + case INTEL_PT_PTWRITE_IP: + case INTEL_PT_EXSTOP: + case INTEL_PT_EXSTOP_IP: + case INTEL_PT_MWAIT: + case INTEL_PT_PWRE: + case INTEL_PT_PWRX: + case INTEL_PT_BBP: + case INTEL_PT_BIP: + case INTEL_PT_BEP: + case INTEL_PT_BEP_IP: + default: + return HOP_PROCESS; + } +} + static int intel_pt_walk_trace(struct intel_pt_decoder *decoder) { bool no_tip = false; @@ -1885,6 +2011,19 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder) if (err) return err; next: + if (decoder->hop) { + switch (intel_pt_hop_trace(decoder, &no_tip, &err)) { + case HOP_IGNORE: + continue; + case HOP_RETURN: + return err; + case HOP_AGAIN: + goto next; + default: + break; + } + } + switch (decoder->packet.type) { case INTEL_PT_TNT: if (!decoder->packet.count) @@ -1914,6 +2053,12 @@ next: decoder->state.from_ip = 0; decoder->state.to_ip = decoder->ip; decoder->state.type |= INTEL_PT_TRACE_BEGIN; + /* + * In hop mode, resample to get the to_ip as an + * "instruction" sample. + */ + if (decoder->hop) + decoder->pkt_state = INTEL_PT_STATE_RESAMPLE; return 0; } @@ -2033,7 +2178,7 @@ next: case INTEL_PT_MODE_TSX: /* MODE_TSX need not be followed by FUP */ - if (!decoder->pge) { + if (!decoder->pge || decoder->in_psb) { intel_pt_update_in_tx(decoder); break; } @@ -2424,7 +2569,11 @@ static int intel_pt_sync_ip(struct intel_pt_decoder *decoder) if (err) return err; - decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; + /* In hop mode, resample to get the to_ip as an "instruction" sample */ + if (decoder->hop) + decoder->pkt_state = INTEL_PT_STATE_RESAMPLE; + else + decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->overflow = false; decoder->state.from_ip = 0; @@ -2545,7 +2694,14 @@ static int intel_pt_sync(struct intel_pt_decoder *decoder) if (decoder->ip) { decoder->state.type = 0; /* Do not have a sample */ - decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; + /* + * In hop mode, resample to get the PSB FUP ip as an + * "instruction" sample. + */ + if (decoder->hop) + decoder->pkt_state = INTEL_PT_STATE_RESAMPLE; + else + decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; } else { return intel_pt_sync_ip(decoder); } @@ -2609,6 +2765,9 @@ const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder) if (err == -EAGAIN) err = intel_pt_walk_trace(decoder); break; + case INTEL_PT_STATE_RESAMPLE: + err = intel_pt_resample(decoder); + break; default: err = intel_pt_bug(decoder); break; diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h index e289e463d635..8645fc265481 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h @@ -250,6 +250,7 @@ struct intel_pt_params { uint32_t tsc_ctc_ratio_n; uint32_t tsc_ctc_ratio_d; enum intel_pt_param_flags flags; + unsigned int quick; }; struct intel_pt_decoder; diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c index 0715d6e23b2f..2a8d245351e7 100644 --- a/tools/perf/util/intel-pt.c +++ b/tools/perf/util/intel-pt.c @@ -1030,6 +1030,7 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt, params.mtc_period = intel_pt_mtc_period(pt); params.tsc_ctc_ratio_n = pt->tsc_ctc_ratio_n; params.tsc_ctc_ratio_d = pt->tsc_ctc_ratio_d; + params.quick = pt->synth_opts.quick; if (pt->filts.cnt > 0) params.pgd_ip = intel_pt_pgd_ip; @@ -1423,7 +1424,10 @@ static int intel_pt_synth_instruction_sample(struct intel_pt_queue *ptq) sample.id = ptq->pt->instructions_id; sample.stream_id = ptq->pt->instructions_id; - sample.period = ptq->state->tot_insn_cnt - ptq->last_insn_cnt; + if (pt->synth_opts.quick) + sample.period = 1; + else + sample.period = ptq->state->tot_insn_cnt - ptq->last_insn_cnt; sample.cyc_cnt = ptq->ipc_cyc_cnt - ptq->last_in_cyc_cnt; if (sample.cyc_cnt) { -- 2.11.0