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perf intel-pt: Allow decoding with branch tracing disabled

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The kernel now supports the disabling of branch tracing, however the
decoder assumes branch tracing is always enabled. Pass through a parameter
to indicate whether branch tracing is enabled and use it to avoid cases
when the decoder is expecting branch packets. There are 2 such cases.
First, FUP packets which can bind to an IP even when there is no branch
tracing. Secondly, the decoder will try to use branch packets to find an IP
to start decoding or to recover from errors.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1495786658-18063-11-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter
2017-05-26 11:17:11 +03:00
committed by Arnaldo Carvalho de Melo
parent 04194207fe
commit 839598176b
3 changed files with 28 additions and 0 deletions
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13
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
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@@ -106,6 +106,7 @@ struct intel_pt_decoder {
const unsigned char *buf;
size_t len;
bool return_compression;
bool branch_enable;
bool mtc_insn;
bool pge;
bool have_tma;
@@ -214,6 +215,7 @@ struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
decoder->pgd_ip = params->pgd_ip;
decoder->data = params->data;
decoder->return_compression = params->return_compression;
decoder->branch_enable = params->branch_enable;
decoder->period = params->period;
decoder->period_type = params->period_type;
@@ -1650,6 +1652,10 @@ next:
break;
}
intel_pt_set_last_ip(decoder);
if (!decoder->branch_enable) {
decoder->ip = decoder->last_ip;
break;
}
err = intel_pt_walk_fup(decoder);
if (err != -EAGAIN) {
if (err)
@@ -1964,6 +1970,13 @@ static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
decoder->set_fup_tx_flags = 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;
}
intel_pt_log("Scanning for full IP\n");
err = intel_pt_walk_to_ip(decoder);
if (err)