aboutsummaryrefslogtreecommitdiffstats
path: root/tools
diff options
context:
space:
mode:
authorAdrian Hunter <adrian.hunter@intel.com>2020-07-10 18:11:04 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-08-06 09:02:43 -0300
commit347a7389a7cc9b91f80deb8d7043e9827d08b328 (patch)
tree13bd633d1f0d0b4b5df2002df6d2e9f4f9ed2d62 /tools
parentperf intel-pt: Add support for decoding FUP/TIP only (diff)
downloadlinux-dev-347a7389a7cc9b91f80deb8d7043e9827d08b328.tar.xz
linux-dev-347a7389a7cc9b91f80deb8d7043e9827d08b328.zip
perf intel-pt: Add support for decoding PSB+ only
A single q option decodes ip from only FUP/TIP packets. Make it so that repeating the q option (i.e. qq) decodes only PSB+, getting ip if there is a FUP packet within PSB+ (i.e. between PSB and PSBEND). 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 $ time perf script --itrace=biqq | wc -l 1883 real 0m0.047s user 0m0.043s sys 0m0.009s Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lore.kernel.org/lkml/20200710151104.15137-13-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/Documentation/perf-intel-pt.txt15
-rw-r--r--tools/perf/util/intel-pt-decoder/intel-pt-decoder.c18
2 files changed, 33 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-intel-pt.txt b/tools/perf/Documentation/perf-intel-pt.txt
index f9fe4a4040ba..d5a266d7f15b 100644
--- a/tools/perf/Documentation/perf-intel-pt.txt
+++ b/tools/perf/Documentation/perf-intel-pt.txt
@@ -999,6 +999,21 @@ What *will* be decoded with the (single) q option:
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.
+Repeating the q option (double-q i.e. qq) results in even faster decoding and even
+less detail. The decoder decodes only extended PSB (PSB+) packets, getting the
+instruction pointer if there is a FUP packet within PSB+ (i.e. between PSB and
+PSBEND). Note PSB packets occur regularly in the trace based on the psb_period
+config term (refer config terms section). There will be a FUP packet if the
+PSB+ occurs while control flow is being traced.
+
+What will *not* be decoded with the qq option:
+
+ - everything except instruction pointer associated with PSB packets
+
+What *will* be decoded with the qq option:
+
+ - instruction pointer associated with PSB packets
+
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 ccb204b1a050..697513f35154 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -113,6 +113,7 @@ struct intel_pt_decoder {
bool in_psb;
bool hop;
bool hop_psb_fup;
+ bool leap;
enum intel_pt_param_flags flags;
uint64_t pos;
uint64_t last_ip;
@@ -240,6 +241,7 @@ struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
decoder->return_compression = params->return_compression;
decoder->branch_enable = params->branch_enable;
decoder->hop = params->quick >= 1;
+ decoder->leap = params->quick >= 2;
decoder->flags = params->flags;
@@ -1903,9 +1905,18 @@ static int intel_pt_resample(struct intel_pt_decoder *decoder)
#define HOP_RETURN 2
#define HOP_AGAIN 3
+static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);
+
/* 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)
{
+ /* Leap from PSB to PSB, getting ip from FUP within PSB+ */
+ if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
+ *err = intel_pt_scan_for_psb(decoder);
+ if (*err)
+ return HOP_RETURN;
+ }
+
switch (decoder->packet.type) {
case INTEL_PT_TNT:
return HOP_IGNORE;
@@ -2681,6 +2692,7 @@ static int intel_pt_sync(struct intel_pt_decoder *decoder)
decoder->ip = 0;
intel_pt_clear_stack(&decoder->stack);
+leap:
err = intel_pt_scan_for_psb(decoder);
if (err)
return err;
@@ -2702,6 +2714,12 @@ static int intel_pt_sync(struct intel_pt_decoder *decoder)
decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
else
decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
+ } else if (decoder->leap) {
+ /*
+ * In leap mode, only PSB+ is decoded, so keeping leaping to the
+ * next PSB until there is an ip.
+ */
+ goto leap;
} else {
return intel_pt_sync_ip(decoder);
}