perf-sched(1)
==============

NAME
----
perf-sched - Tool to trace/measure scheduler properties (latencies)

SYNOPSIS
--------
[verse]
'perf sched' {record|latency|map|replay|script|timehist}

DESCRIPTION
-----------
There are several variants of 'perf sched':

  'perf sched record <command>' to record the scheduling events
  of an arbitrary workload.

  'perf sched latency' to report the per task scheduling latencies
  and other scheduling properties of the workload.

  'perf sched script' to see a detailed trace of the workload that
   was recorded (aliased to 'perf script' for now).

  'perf sched replay' to simulate the workload that was recorded
  via perf sched record. (this is done by starting up mockup threads
  that mimic the workload based on the events in the trace. These
  threads can then replay the timings (CPU runtime and sleep patterns)
  of the workload as it occurred when it was recorded - and can repeat
  it a number of times, measuring its performance.)

  'perf sched map' to print a textual context-switching outline of
  workload captured via perf sched record.  Columns stand for
  individual CPUs, and the two-letter shortcuts stand for tasks that
  are running on a CPU. A '*' denotes the CPU that had the event, and
  a dot signals an idle CPU.

  'perf sched timehist' provides an analysis of scheduling events.
    
    Example usage:
        perf sched record -- sleep 1
        perf sched timehist
    
   By default it shows the individual schedule events, including the wait
   time (time between sched-out and next sched-in events for the task), the
   task scheduling delay (time between wakeup and actually running) and run
   time for the task:
    
                time    cpu  task name             wait time  sch delay   run time
                             [tid/pid]                (msec)     (msec)     (msec)
      -------------- ------  --------------------  ---------  ---------  ---------
        79371.874569 [0011]  gcc[31949]                0.014      0.000      1.148
        79371.874591 [0010]  gcc[31951]                0.000      0.000      0.024
        79371.874603 [0010]  migration/10[59]          3.350      0.004      0.011
        79371.874604 [0011]  <idle>                    1.148      0.000      0.035
        79371.874723 [0005]  <idle>                    0.016      0.000      1.383
        79371.874746 [0005]  gcc[31949]                0.153      0.078      0.022
    ...
    
   Times are in msec.usec.

OPTIONS
-------
-i::
--input=<file>::
        Input file name. (default: perf.data unless stdin is a fifo)

-v::
--verbose::
        Be more verbose. (show symbol address, etc)

-D::
--dump-raw-trace=::
        Display verbose dump of the sched data.

OPTIONS for 'perf sched map'
----------------------------

--compact::
	Show only CPUs with activity. Helps visualizing on high core
	count systems.

--cpus::
	Show just entries with activities for the given CPUs.

--color-cpus::
	Highlight the given cpus.

--color-pids::
	Highlight the given pids.

OPTIONS for 'perf sched timehist'
---------------------------------
-k::
--vmlinux=<file>::
    vmlinux pathname

--kallsyms=<file>::
    kallsyms pathname

-g::
--no-call-graph::
	Do not display call chains if present.

--max-stack::
	Maximum number of functions to display in backtrace, default 5.

-s::
--summary::
    Show only a summary of scheduling by thread with min, max, and average
    run times (in sec) and relative stddev.

-S::
--with-summary::
    Show all scheduling events followed by a summary by thread with min,
    max, and average run times (in sec) and relative stddev.

--symfs=<directory>::
    Look for files with symbols relative to this directory.

-V::
--cpu-visual::
	Show visual aid for sched switches by CPU: 'i' marks idle time,
	's' are scheduler events.

-w::
--wakeups::
	Show wakeup events.

-M::
--migrations::
	Show migration events.

-I::
--idle-hist::
	Show idle-related events only.

--time::
	Only analyze samples within given time window: <start>,<stop>. Times
	have the format seconds.microseconds. If start is not given (i.e., time
	string is ',x.y') then analysis starts at the beginning of the file. If
	stop time is not given (i.e, time string is 'x.y,') then analysis goes
	to end of file.


SEE ALSO
--------
linkperf:perf-record[1]
td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;</td><td class='right'>2017-01-31 10:25:25 +0100</td></tr>
<tr><th>committer</th><td>Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;</td><td class='right'>2017-01-31 13:41:46 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/phy/phy-generic.h?id=92c715fca907686f5298220ece53423e38ba3aed'>92c715fca907686f5298220ece53423e38ba3aed</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/phy/phy-generic.h?id=92c715fca907686f5298220ece53423e38ba3aed'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=92c715fca907686f5298220ece53423e38ba3aed'>286158fdad04c9b54955350abb95d4f1c0dc860a</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/phy/phy-generic.h?id=92c715fca907686f5298220ece53423e38ba3aed'>drivers/usb/phy/phy-generic.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/phy/phy-generic.h?id=e6e7b48b295afa5a5ab440de0a94d9ad8b3ce2d0'>e6e7b48b295afa5a5ab440de0a94d9ad8b3ce2d0</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/phy/phy-generic.h?id=92c715fca907686f5298220ece53423e38ba3aed&amp;id2=e6e7b48b295afa5a5ab440de0a94d9ad8b3ce2d0'>diff</a>)</td></tr></table>
<div class='commit-subject'>drm/atomic: Fix double free in drm_atomic_state_default_clear</div><div class='commit-msg'>drm_atomic_helper_page_flip and drm_atomic_ioctl set their own events
in crtc_state-&gt;event. But when it's set the event is freed in 2 places.

Solve this by only freeing the event in the atomic ioctl when it
allocated its own event.

This has been broken twice. The first time when the code was introduced,
but only in the corner case when an event is allocated, but more crtc's
were included by atomic check and then failing. This can mostly
happen when you do an atomic modeset in i915 and the display clock is
changed, which forces all crtc's to be included to the state.

This has been broken worse by adding in-fences support, which caused
the double free to be done unconditionally.

[IGT] kms_rotation_crc: starting subtest primary-rotation-180
=============================================================================
BUG kmalloc-128 (Tainted: G     U         ): Object already free
-----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: Allocated in drm_atomic_helper_setup_commit+0x285/0x2f0 [drm_kms_helper] age=0 cpu=3 pid=1529
 ___slab_alloc+0x308/0x3b0
 __slab_alloc+0xd/0x20
 kmem_cache_alloc_trace+0x92/0x1c0
 drm_atomic_helper_setup_commit+0x285/0x2f0 [drm_kms_helper]
 intel_atomic_commit+0x35/0x4f0 [i915]
 drm_atomic_commit+0x46/0x50 [drm]
 drm_mode_atomic_ioctl+0x7d4/0xab0 [drm]
 drm_ioctl+0x2b3/0x490 [drm]
 do_vfs_ioctl+0x69c/0x700
 SyS_ioctl+0x4e/0x80
 entry_SYSCALL_64_fastpath+0x13/0x94
INFO: Freed in drm_event_cancel_free+0xa3/0xb0 [drm] age=0 cpu=3 pid=1529
 __slab_free+0x48/0x2e0
 kfree+0x159/0x1a0
 drm_event_cancel_free+0xa3/0xb0 [drm]
 drm_mode_atomic_ioctl+0x86d/0xab0 [drm]
 drm_ioctl+0x2b3/0x490 [drm]
 do_vfs_ioctl+0x69c/0x700
 SyS_ioctl+0x4e/0x80
 entry_SYSCALL_64_fastpath+0x13/0x94
INFO: Slab 0xffffde1f0997b080 objects=17 used=2 fp=0xffff92fb65ec2578 flags=0x200000000008101
INFO: Object 0xffff92fb65ec2578 @offset=1400 fp=0xffff92fb65ec2ae8

Redzone ffff92fb65ec2570: bb bb bb bb bb bb bb bb                          ........
Object ffff92fb65ec2578: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ffff92fb65ec2588: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ffff92fb65ec2598: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ffff92fb65ec25a8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ffff92fb65ec25b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ffff92fb65ec25c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ffff92fb65ec25d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ffff92fb65ec25e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5  kkkkkkkkkkkkkkk.
Redzone ffff92fb65ec25f8: bb bb bb bb bb bb bb bb                          ........
Padding ffff92fb65ec2738: 5a 5a 5a 5a 5a 5a 5a 5a                          ZZZZZZZZ
CPU: 3 PID: 180 Comm: kworker/3:2 Tainted: G    BU          4.10.0-rc6-patser+ #5039
Hardware name:                  /NUC5PPYB, BIOS PYBSWCEL.86A.0031.2015.0601.1712 06/01/2015
Workqueue: events intel_atomic_helper_free_state [i915]
Call Trace:
 dump_stack+0x4d/0x6d
 print_trailer+0x20c/0x220
 free_debug_processing+0x1c6/0x330
 ? drm_atomic_state_default_clear+0xf7/0x1c0 [drm]
 __slab_free+0x48/0x2e0
 ? drm_atomic_state_default_clear+0xf7/0x1c0 [drm]
 kfree+0x159/0x1a0
 drm_atomic_state_default_clear+0xf7/0x1c0 [drm]
 ? drm_atomic_state_clear+0x30/0x30 [drm]
 intel_atomic_state_clear+0xd/0x20 [i915]
 drm_atomic_state_clear+0x1a/0x30 [drm]
 __drm_atomic_state_free+0x13/0x60 [drm]
 intel_atomic_helper_free_state+0x5d/0x70 [i915]
 process_one_work+0x260/0x4a0
 worker_thread+0x2d1/0x4f0
 kthread+0x127/0x130
 ? process_one_work+0x4a0/0x4a0
 ? kthread_stop+0x120/0x120
 ret_from_fork+0x29/0x40
FIX kmalloc-128: Object at 0xffff92fb65ec2578 not freed

Fixes: 3b24f7d67581 ("drm/atomic: Add struct drm_crtc_commit to track async updates")
Fixes: 9626014258a5 ("drm/fence: add in-fences support")
Cc: &lt;stable@vger.kernel.org&gt; # v4.8+
Cc: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Signed-off-by: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Reviewed-by: Gustavo Padovan &lt;gustavo.padovan@collabora.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: http://patchwork.freedesktop.org/patch/msgid/1485854725-27640-1-git-send-email-maarten.lankhorst@linux.intel.com
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=92c715fca907686f5298220ece53423e38ba3aed'>Diffstat</a> (limited to 'drivers/usb/phy/phy-generic.h')</div><table summary='diffstat' class='diffstat'>