TODO

+ Add KVM tests, specifically
	PERF_RECORD_MISC_GUEST_KERNEL and PERF_RECORD_MISC_GUEST_USER events.
+ Test the new cycles field in LBR entries on Sandybridge
+ Test for new CONTEXT_SWITCH records
+ In sampling, be sure to handle the various sample_header values

+ Test for PERF_FLAG_FD_CLOEXEC

+ Fix up the test for PERF_IOC_PERIOD and if it takes place right away.

+ Add test for Fixed Counter 2 (retired instructions) being different.
  Basically run 5 instructions events, compare results
  

+ Add test for ring-buffer size of 0 or 1
  (possibly causes kernel bug?)
  
+ Add test for IVB constraints


+ Wakeup events not equal to 1

+ single-shot RT counts

+ the bug with overflow even after event closed


PERF_FLAG_FD_OUTPUT
PERF_FLAG_FD_NO_GROUP


get perf cache-detection code going

inherit?
inherit and PERF_FORMAT_GROUP?


document:
  pinned flag?

perf tests:
+ All generalized events
+ More multi-threaded test cases
+ More assembler code in the cache load/stores tests

PAPI tests:
 + Invert flag
 + Max number of SW events


From Phil:
Do you guys have a test for:

a) grouped, non-multiplexed counters (where you can read/start/stop on one FD)
b) multiplexed, grouped counters
c) the portion of perf_events that uses counter indexing (returns a [5] array).
   (I'm not sure what this is useful for yet...sampling?)


Will Deacon:

If I try using perf with event groups on a mainline kernel, only the group
leader counts:


linaro@mashed-potato:~$ perf stat --no-scale -g -e task-clock -e cpu-clock -e cs
+-- ls
hwb  linux

 Performance counter stats for 'ls':

         17.545541 task-clock                #    0.634 CPUs utilized
          0.000000 cpu-clock
                 0 cs                        #    0.000 M/sec

       0.027684984 seconds time elapsed


This is fixed by b79387ef ("perf: Fix enable_on_exec for sibling events")
in -next (20111222) but I can't see this queued anywhere for 3.2 (I thought
I might see it in -rc7).

Is this going in for the final cut, or will groups just be borked until 3.3?

How can this be a regression? Its always been like that. At worst its a
broken new feature.

Also, you really shouldn't set enable_on_exec on non group leaders,
that's just daft. But yes that patch sorts it. Something like the below
should too.

+ test guest exclude support
  attr.exclude_{guest,host}



commit a4f144ebbdf6f7807c477bce8e136047ed27321f
Author: David Carrillo-Cisneros <davidcc@google.com>
Date:   Wed Jun 1 12:33:05 2016 -0700

    perf/core: Fix crash due to account/unaccount_sb_event() inconsistency
    
    unaccount_pmu_sb_event() did not check for attributes in event->attr
    before calling detach_sb_event(), while account_pmu_event() did.
    
    This caused NULL pointer reference in cgroup events that did not
    have any of the attributes checked by account_pmu_event().
    
    To trigger the bug just wait for a cgroup event to terminate, e.g.:
    
      $ mkdir /dev/cgroup/devices/test
      $ perf stat -e cycles -a -G test sleep 0
    
    ... see crash ...




Date: Wed, 14 Sep 2016 22:38:45 -0700
From: Stephane Eranian 
Subject: slow perf ioctl()

Here is another thing I've run into lately having to do with
ioctl(fd, PERF_IOC_REFRESH, 1) on self-monitoring thread.
The ioctl() takes seconds to execute. I have not yet had the time
to track down why.  Any of your tests exhibiting this problem?