linux/tools
Alexander Shishkin 05a1f47ed4 perf tools: Handle partial AUX records and print a warning
This patch decodes the 'partial' flag in AUX records and prints
a warning to the user, so that they don't have to guess why their
PT traces contain gaps (or missing altogether):

  Warning:
  AUX data had gaps in it 8 times out of 8!

  Are you running a KVM guest in the background?

Trying to be even more helpful, we will detect if the user's kvm driver sets up
exclusive VMX root mode for the entire lifespan of the kvm process:

  Reloading kvm_intel module with vmm_exclusive=0
  will reduce the gaps to only guest's timeslices.

Note however, that you'll still have gaps in cpu-wide traces even with
vmm_exclusive=0, but the number of gaps will be below 100% (as opposed to the
above example).

Currently this is the only reason for partial records.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vince@deater.net>
Link: http://lkml.kernel.org/r/8760j941ig.fsf@ashishki-desk.ger.corp.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-03-17 11:52:18 -03:00
..
accounting tools: move accounting tool from Documentation 2016-09-23 13:07:15 -06:00
arch tools headers: Sync {tools/,}arch/x86/include/asm/cpufeatures.h 2017-03-16 09:23:22 -03:00
build tools build: Use the same CC for feature detection and actual build 2017-03-03 19:07:19 -03:00
cgroup
firewire
gpio gpio-hammer: fix make consumer_label suitable to work on gpio-nails 2017-01-26 16:29:09 +01:00
hv Char/Misc driver patches for 4.10-rc1 2016-12-13 12:11:01 -08:00
iio iio: Add channel for Gravity 2017-01-05 13:02:25 +00:00
include tools include: Sync {,tools/}include/uapi/linux/perf_event.h 2017-03-17 11:49:09 -03:00
kvm/kvm_stat
laptop tools: move laptops dslm tool from Documentation 2016-09-23 13:07:21 -06:00
leds tools/leds: Add led_hw_brightness_mon program 2017-02-14 22:20:23 +01:00
lguest scripts/spelling.txt: add "overide" pattern and fix typo instances 2017-03-09 17:01:09 -08:00
lib tools lib api fs: Introduce sysfs__read_bool 2017-03-17 11:49:09 -03:00
net
nfsd
objtool objtool: Fix another GCC jump table detection issue 2017-03-07 08:42:55 +01:00
pcmcia tools: move pcmcia crc32hash tool from Documentation 2016-09-23 13:07:27 -06:00
perf perf tools: Handle partial AUX records and print a warning 2017-03-17 11:52:18 -03:00
power Power management turbostat utility updates for v4.11-rc1 2017-03-02 17:41:27 -08:00
scripts tools arch x86: Include asm/cmpxchg.h 2017-03-03 19:07:13 -03:00
spi spi: spidev_test: Fix input file check when transferring file 2016-11-04 09:56:09 -06:00
testing Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-03-14 21:31:23 -07:00
thermal/tmon
time
usb USB: changes for v4.11 2017-01-26 15:36:28 +01:00
virtio tools/virtio/ringtest: tweaks for s390 2017-01-19 23:46:32 +02:00
vm tools/vm: add missing Makefile rules 2017-02-22 16:41:26 -08:00
Makefile tools/leds: Add uledmon program for monitoring userspace LEDs 2016-11-22 12:07:02 +01:00