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perf intel-pt: Fix state setting when receiving overflow (OVF) packet

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An overflow (OVF packet) is treated as an error because it represents a
loss of trace data, but there is no loss of synchronization, so the packet
state should be INTEL_PT_STATE_IN_SYNC not INTEL_PT_STATE_ERR_RESYNC.

To support that, some additional variables must be reset, and the FUP
packet that may follow OVF is treated as an FUP event.

Fixes: f4aa081949 ("perf tools: Add Intel PT decoder")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org # v5.15+
Link: https://lore.kernel.org/r/20211210162303.2288710-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter 2021-12-10 18:23:00 +02:00 committed by Arnaldo Carvalho de Melo
parent 4c761d805b
commit c79ee2b216
1 changed files with 28 additions and 4 deletions
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30
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
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@ -1249,6 +1249,20 @@ static bool intel_pt_fup_event(struct intel_pt_decoder *decoder)
decoder->state.type |= INTEL_PT_BLK_ITEMS;
ret = true;
}
if (decoder->overflow) {
decoder->overflow = false;
if (!ret && !decoder->pge) {
if (decoder->hop) {
decoder->state.type = 0;
decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
}
decoder->pge = true;
decoder->state.type |= INTEL_PT_BRANCH | INTEL_PT_TRACE_BEGIN;
decoder->state.from_ip = 0;
decoder->state.to_ip = decoder->ip;
return true;
}
}
if (ret) {
decoder->state.from_ip = decoder->ip;
decoder->state.to_ip = 0;
@ -1602,7 +1616,16 @@ static int intel_pt_overflow(struct intel_pt_decoder *decoder)
intel_pt_clear_tx_flags(decoder);
intel_pt_set_nr(decoder);
decoder->timestamp_insn_cnt = 0;
decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
decoder->state.from_ip = decoder->ip;
decoder->ip = 0;
decoder->pge = false;
decoder->set_fup_tx_flags = false;
decoder->set_fup_ptw = false;
decoder->set_fup_mwait = false;
decoder->set_fup_pwre = false;
decoder->set_fup_exstop = false;
decoder->set_fup_bep = false;
decoder->overflow = true;
return -EOVERFLOW;
}
@ -2957,6 +2980,7 @@ next:
case INTEL_PT_TIP_PGE: {
decoder->pge = true;
decoder->overflow = false;
intel_pt_mtc_cyc_cnt_pge(decoder);
intel_pt_set_nr(decoder);
if (decoder->packet.count == 0) {
@ -3462,10 +3486,10 @@ static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
decoder->set_fup_pwre = false;
decoder->set_fup_exstop = false;
decoder->set_fup_bep = false;
decoder->overflow = false;
if (!decoder->branch_enable) {
decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
decoder->overflow = false;
decoder->state.type = 0; /* Do not have a sample */
return 0;
}
@ -3480,7 +3504,6 @@ static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
else
decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
decoder->overflow = false;
decoder->state.from_ip = 0;
decoder->state.to_ip = decoder->ip;
@ -3699,6 +3722,7 @@ const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
if (err) {
decoder->state.err = intel_pt_ext_err(err);
if (err != -EOVERFLOW)
decoder->state.from_ip = decoder->ip;
intel_pt_update_sample_time(decoder);
decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;