kernel/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c, branch linux-4.16.y

perf intel-pt: Fix timestamp following overflow

2018-04-19T06:54:07Z

commit 91d29b288aed3406caf7c454bf2b898c96cfd177 upstream. timestamp_insn_cnt is used to estimate the timestamp based on the number of instructions since the last known timestamp. If the estimate is not accurate enough decoding might not be correctly synchronized with side-band events causing more trace errors. However there are always timestamps following an overflow, so the estimate is not needed and can indeed result in more errors. Suppress the estimate by setting timestamp_insn_cnt to zero. Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1520431349-30689-5-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix error recovery from missing TIP packet

2018-04-19T06:54:07Z

commit 1c196a6c771c47a2faa63d38d913e03284f73a16 upstream. When a TIP packet is expected but there is a different packet, it is an error. However the unexpected packet might be something important like a TSC packet, so after the error, it is necessary to continue from there, rather than the next packet. That is achieved by setting pkt_step to zero. Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1520431349-30689-4-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix overlap detection to identify consecutive buffers correctly

2018-04-19T06:54:06Z

commit 117db4b27bf08dba412faf3924ba55fe970c57b8 upstream. Overlap detection was not not updating the buffer's 'consecutive' flag. Marking buffers consecutive has the advantage that decoding begins from the start of the buffer instead of the first PSB. Fix overlap detection to identify consecutive buffers correctly. Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1520431349-30689-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Do not use TSC packets for calculating CPU cycles to TSC

2017-06-30T14:50:55Z

CBR (core-to-bus ratio) packets provide an indication of CPU frequency. A more accurate measure can be made by counting the cycles (given by CYC packets) in between other timing packets (either MTC or TSC). Using TSC packets has at least 2 issues: 1) timing might have stopped (e.g. mwait) or 2) TSC packets within PSB+ might slip past CYC packets. For now, simply do not use TSC packets for calculating CPU cycles to TSC. That leaves the case where 2 MTC packets are used, otherwise falling back to the CBR value. Signed-off-by: Adrian Hunter Cc: Andi Kleen Link: http://lkml.kernel.org/r/1495786658-18063-37-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Add decoder support for CBR events

2017-06-21T14:35:51Z

Add decoder support for informing the tools of changes to the core-to-bus ratio (CBR). Signed-off-by: Adrian Hunter Cc: Andi Kleen Link: http://lkml.kernel.org/r/1495786658-18063-16-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Add reserved byte to CBR packet payload

2017-06-21T14:35:50Z

Future proof CBR packet decoding by passing through also the undefined 'reserved' byte in the packet payload. Signed-off-by: Adrian Hunter Cc: Andi Kleen Link: http://lkml.kernel.org/r/1495786658-18063-15-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Add decoder support for ptwrite and power event packets

2017-06-21T14:35:50Z

Add decoder support for PTWRITE, MWAIT, PWRE, PWRX and EXSTOP packets. This patch only affects the decoder, so the tools still do not select or consume the new information. That is added in subsequent patches. Signed-off-by: Adrian Hunter Cc: Andi Kleen Link: http://lkml.kernel.org/r/1495786658-18063-14-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Allow decoding with branch tracing disabled

2017-06-21T14:35:48Z

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 Cc: Andi Kleen Link: http://lkml.kernel.org/r/1495786658-18063-11-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Add missing __fallthrough

2017-06-21T14:35:47Z

perf tools uses __fallthrough. Add missing __fallthrough to a switch statement. Signed-off-by: Adrian Hunter Cc: Andi Kleen Link: http://lkml.kernel.org/r/1495786658-18063-10-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Clear FUP flag on error

2017-06-21T14:35:47Z

Sometimes a FUP packet is associated with a TSX transaction and a flag is set to indicate that. Ensure that flag is cleared on any error condition because at that point the decoder can no longer assume it is correct. Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1495786658-18063-9-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo