OpenCloudOS-Kernel/tools/perf/util/intel-pt-decoder
Adrian Hunter b4b046ff9e perf intel-pt: Add a config for max loops without consuming a packet
The Intel PT decoder limits the number of unconditional branches (e.g.
jmps) decoded without consuming any trace packets. Generally, a loop
needs a conditional branch which generates a TNT packet, whereas a "ret"
instruction will generate a TIP or TNT packet. So exceeding the limit is
assumed to be a never-ending loop, which can happen if there has been a
decoding error putting the decoder at the wrong place in the code.

Up until now, the limit of 10000 has been enough but some analytic
purposes have been reported to exceed that.

Increase the limit to 100000, and make it configurable via perf config
intel-pt.max-loops. Also amend the "Never-ending loop" message to
mention the configuration entry.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20210701175132.3977-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-07 11:40:56 -03:00
..
Build perf intel-pt: Use shared x86 insn decoder 2019-08-31 22:27:52 -03:00
intel-pt-decoder.c perf intel-pt: Add a config for max loops without consuming a packet 2021-07-07 11:40:56 -03:00
intel-pt-decoder.h perf intel-pt: Add a config for max loops without consuming a packet 2021-07-07 11:40:56 -03:00
intel-pt-insn-decoder.c tools/perf: Convert to insn_decode() 2021-03-15 12:41:26 +01:00
intel-pt-insn-decoder.h perf intel_pt: Add vmlaunch and vmresume as branches 2021-02-18 16:13:30 -03:00
intel-pt-log.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
intel-pt-log.h perf intel-pt: Add VM Time Correlation to decoder 2021-05-12 12:43:11 -03:00
intel-pt-pkt-decoder.c perf intel-pt: Retain the last PIP packet payload as is 2021-02-18 16:13:46 -03:00
intel-pt-pkt-decoder.h perf intel-pt: Retain the last PIP packet payload as is 2021-02-18 16:13:46 -03:00