mirror_ubuntu-kernels/tools
James Clark c1a6165a63 perf cs-etm: Prevent and warn on underflows during timestamp calculation.
When a zero timestamp is encountered, warn once. This is to make
hardware or configuration issues visible. Also suggest that the issue
can be worked around with the --itrace=Z option.

When an underflow with a non-zero timestamp occurs, warn every time.
This is an unexpected scenario, and with increasing timestamps, it's
unlikely that it would occur more than once, therefore it should be
ok to warn every time.

Only try to calculate the timestamp by subtracting the instruction
count if neither of the above cases are true. This makes attempting
to decode files with zero timestamps in non-timeless mode
more consistent. Currently it can half work if the timestamp wraps
around and becomes non-zero, although the behavior is undefined and
unpredictable.

Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Cc: Al Grant <al.grant@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Branislav Rankov <branislav.rankov@arm.com>
Cc: Denis Nikitin <denik@chromium.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lore.kernel.org/lkml/20210517131741.3027-4-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-05-17 11:06:56 -03:00
..
accounting
arch tools headers cpufeatures: Sync with the kernel sources 2021-05-10 09:01:00 -03:00
bootconfig
bpf bpftool: Dump more info about DATASEC members 2021-04-23 14:05:26 -07:00
build perf tools changes for v5.13: 1st batch 2021-05-01 12:22:38 -07:00
cgroup tools/cgroup/slabinfo.py: updated to work on current kernel 2021-04-23 14:42:40 -07:00
debugging tools: Fix a typo in kernel-chktaint 2021-04-08 11:41:22 -06:00
edid
firewire
firmware
gpio tools: gpio-utils: fix various kernel-doc warnings 2021-03-26 14:56:19 +01:00
hv
iio iio: event_monitor: Enable events before monitoring 2021-03-25 19:13:52 +00:00
include tools headers UAPI: Sync perf_event.h with the kernel sources 2021-05-10 09:01:01 -03:00
io_uring
kvm/kvm_stat tools/kvm_stat: Fix documentation typo 2021-05-07 06:06:22 -04:00
laptop
leds
lib Networking fixes for 5.13-rc1, including fixes from bpf, can 2021-05-08 08:31:46 -07:00
memory-model doc: update rcu_dereference.rst reference 2021-04-06 14:45:04 +02:00
objtool Objtool updates in this cycle were: 2021-04-28 12:53:24 -07:00
pci
pcmcia
perf perf cs-etm: Prevent and warn on underflows during timestamp calculation. 2021-05-17 11:06:56 -03:00
power Merge branch 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2021-05-05 12:24:29 -07:00
scripts tools: disable -Wno-type-limits 2021-05-06 19:24:11 -07:00
spi spi: tools: make a symbolic link to the header file spi.h 2021-04-22 16:30:39 +01:00
testing * Lots of bug fixes. 2021-05-10 12:30:45 -07:00
thermal/tmon tools: do not include scripts/Kbuild.include 2021-04-25 05:26:13 +09:00
time
tracing tools/latency-collector: Remove unneeded semicolon 2021-03-18 12:58:26 -04:00
usb treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
virtio
vm
wmi
Makefile