Merge tag 'trace-v6.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:
 "User events:

   - Use long instead of int for storing the enable set/clear bit, as it
     was found that big endian machines could end up using the wrong
     bits.

   - Split allocating mm and attaching it. This keeps the allocation
     separate from the registration and avoids various races.

   - Remove RCU locking around pin_user_pages_remote() as that can
     schedule. The RCU protection is no longer needed with the above
     split of mm allocation and attaching.

   - Rename the "link" fields of the various structs to something more
     meaningful.

   - Add comments around user_event_mm struct usage and locking
     requirements.

  Timerlat tracer:

   - Fix missed wakeup of timerlat thread caused by the timerlat
     interrupt triggering when tracing is off. The timer interrupt
     handler needs to always wake up the timerlat thread regardless if
     tracing is enabled or not, otherwise, it will never wake up.

  Histograms:

   - Fix regression of breaking the "stacktrace" modifier for variables.
     That modifier cannot be used for values, but can be used for
     variables that are passed from one histogram to the next. This was
     broken when adding the restriction to values as the variable logic
     used the same code.

   - Rename the special field "stacktrace" to "common_stacktrace".

     Special fields (that are not actually part of the event, but can
     act just like event fields, like 'comm' and 'timestamp') should be
     prefixed with 'common_' for consistency. To keep backward
     compatibility, 'stacktrace' can still be used (as with the special
     field 'cpu'), but can be overridden if the event has a field called
     'stacktrace'.

   - Update the synthetic event selftests to use the new name (synthetic
     events are created by histograms)

  Tracing bootup selftests:

   - Reorganize the code to keep artifacts of the selftests not compiled
     in when selftests are not configured.

   - Add various cond_resched() around the selftest code, as the
     softlock watchdog was triggering much more often. It appears that
     the kernel runs slower now with full debugging enabled.

   - While debugging ftrace with ftrace (using an instance ring buffer
     instead of the top level one), I found that the selftests were
     disabling prints to the debug instance.

     This should not happen, as the selftests only disable printing to
     the main buffer as the selftests examine the main buffer to see if
     it has what it expects, and prints can make the tests fail.

     Make the selftests only disable printing to the toplevel buffer,
     and leave the instance buffers alone"

* tag 'trace-v6.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Have function_graph selftest call cond_resched()
  tracing: Only make selftest conditionals affect the global_trace
  tracing: Make tracing_selftest_running/delete nops when not used
  tracing: Have tracer selftests call cond_resched() before running
  tracing: Move setting of tracing_selftest_running out of register_tracer()
  tracing/selftests: Update synthetic event selftest to use common_stacktrace
  tracing: Rename stacktrace field to common_stacktrace
  tracing/histograms: Allow variables to have some modifiers
  tracing/user_events: Document user_event_mm one-shot list usage
  tracing/user_events: Rename link fields for clarity
  tracing/user_events: Remove RCU lock while pinning pages
  tracing/user_events: Split up mm alloc and attach
  tracing/timerlat: Always wakeup the timerlat thread
  tracing/user_events: Use long vs int for atomic bit ops

1 files changed, 32 insertions, 32 deletions

diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst
index 479c9eac6335..3c9b263de9c2 100644
--- a/Documentation/trace/histogram.rst
+++ b/Documentation/trace/histogram.rst
@@ -35,7 +35,7 @@ Documentation written by Tom Zanussi
   in place of an explicit value field - this is simply a count of
   event hits.  If 'values' isn't specified, an implicit 'hitcount'
   value will be automatically created and used as the only value.
-  Keys can be any field, or the special string 'stacktrace', which
+  Keys can be any field, or the special string 'common_stacktrace', which
   will use the event's kernel stacktrace as the key.  The keywords
   'keys' or 'key' can be used to specify keys, and the keywords
   'values', 'vals', or 'val' can be used to specify values.  Compound
@@ -54,7 +54,7 @@ Documentation written by Tom Zanussi
   'compatible' if the fields named in the trigger share the same
   number and type of fields and those fields also have the same names.
   Note that any two events always share the compatible 'hitcount' and
-  'stacktrace' fields and can therefore be combined using those
+  'common_stacktrace' fields and can therefore be combined using those
   fields, however pointless that may be.
 
   'hist' triggers add a 'hist' file to each event's subdirectory.
@@ -547,9 +547,9 @@ Extended error information
   the hist trigger display symbolic call_sites, we can have the hist
   trigger additionally display the complete set of kernel stack traces
   that led to each call_site.  To do that, we simply use the special
-  value 'stacktrace' for the key parameter::
+  value 'common_stacktrace' for the key parameter::
 
-    # echo 'hist:keys=stacktrace:values=bytes_req,bytes_alloc:sort=bytes_alloc' > \
+    # echo 'hist:keys=common_stacktrace:values=bytes_req,bytes_alloc:sort=bytes_alloc' > \
            /sys/kernel/tracing/events/kmem/kmalloc/trigger
 
   The above trigger will use the kernel stack trace in effect when an
@@ -561,9 +561,9 @@ Extended error information
   every callpath to a kmalloc for a kernel compile)::
 
     # cat /sys/kernel/tracing/events/kmem/kmalloc/hist
-    # trigger info: hist:keys=stacktrace:vals=bytes_req,bytes_alloc:sort=bytes_alloc:size=2048 [active]
+    # trigger info: hist:keys=common_stacktrace:vals=bytes_req,bytes_alloc:sort=bytes_alloc:size=2048 [active]
 
-    { stacktrace:
+    { common_stacktrace:
          __kmalloc_track_caller+0x10b/0x1a0
          kmemdup+0x20/0x50
          hidraw_report_event+0x8a/0x120 [hid]
@@ -581,7 +581,7 @@ Extended error information
          cpu_startup_entry+0x315/0x3e0
          rest_init+0x7c/0x80
     } hitcount:          3  bytes_req:         21  bytes_alloc:         24
-    { stacktrace:
+    { common_stacktrace:
          __kmalloc_track_caller+0x10b/0x1a0
          kmemdup+0x20/0x50
          hidraw_report_event+0x8a/0x120 [hid]
@@ -596,7 +596,7 @@ Extended error information
          do_IRQ+0x5a/0xf0
          ret_from_intr+0x0/0x30
     } hitcount:          3  bytes_req:         21  bytes_alloc:         24
-    { stacktrace:
+    { common_stacktrace:
          kmem_cache_alloc_trace+0xeb/0x150
          aa_alloc_task_context+0x27/0x40
          apparmor_cred_prepare+0x1f/0x50
@@ -608,7 +608,7 @@ Extended error information
     .
     .
     .
-    { stacktrace:
+    { common_stacktrace:
          __kmalloc+0x11b/0x1b0
          i915_gem_execbuffer2+0x6c/0x2c0 [i915]
          drm_ioctl+0x349/0x670 [drm]
@@ -616,7 +616,7 @@ Extended error information
          SyS_ioctl+0x81/0xa0
          system_call_fastpath+0x12/0x6a
     } hitcount:      17726  bytes_req:   13944120  bytes_alloc:   19593808
-    { stacktrace:
+    { common_stacktrace:
          __kmalloc+0x11b/0x1b0
          load_elf_phdrs+0x76/0xa0
          load_elf_binary+0x102/0x1650
@@ -625,7 +625,7 @@ Extended error information
          SyS_execve+0x3a/0x50
          return_from_execve+0x0/0x23
     } hitcount:      33348  bytes_req:   17152128  bytes_alloc:   20226048
-    { stacktrace:
+    { common_stacktrace:
          kmem_cache_alloc_trace+0xeb/0x150
          apparmor_file_alloc_security+0x27/0x40
          security_file_alloc+0x16/0x20
@@ -636,7 +636,7 @@ Extended error information
          SyS_open+0x1e/0x20
          system_call_fastpath+0x12/0x6a
     } hitcount:    4766422  bytes_req:    9532844  bytes_alloc:   38131376
-    { stacktrace:
+    { common_stacktrace:
          __kmalloc+0x11b/0x1b0
          seq_buf_alloc+0x1b/0x50
          seq_read+0x2cc/0x370
@@ -1026,7 +1026,7 @@ Extended error information
   First we set up an initially paused stacktrace trigger on the
   netif_receive_skb event::
 
-    # echo 'hist:key=stacktrace:vals=len:pause' > \
+    # echo 'hist:key=common_stacktrace:vals=len:pause' > \
            /sys/kernel/tracing/events/net/netif_receive_skb/trigger
 
   Next, we set up an 'enable_hist' trigger on the sched_process_exec
@@ -1060,9 +1060,9 @@ Extended error information
     $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz
 
     # cat /sys/kernel/tracing/events/net/netif_receive_skb/hist
-    # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused]
+    # trigger info: hist:keys=common_stacktrace:vals=len:sort=hitcount:size=2048 [paused]
 
-    { stacktrace:
+    { common_stacktrace:
          __netif_receive_skb_core+0x46d/0x990
          __netif_receive_skb+0x18/0x60
          netif_receive_skb_internal+0x23/0x90
@@ -1079,7 +1079,7 @@ Extended error information
          kthread+0xd2/0xf0
          ret_from_fork+0x42/0x70
     } hitcount:         85  len:      28884
-    { stacktrace:
+    { common_stacktrace:
          __netif_receive_skb_core+0x46d/0x990
          __netif_receive_skb+0x18/0x60
          netif_receive_skb_internal+0x23/0x90
@@ -1097,7 +1097,7 @@ Extended error information
          irq_thread+0x11f/0x150
          kthread+0xd2/0xf0
     } hitcount:         98  len:     664329
-    { stacktrace:
+    { common_stacktrace:
          __netif_receive_skb_core+0x46d/0x990
          __netif_receive_skb+0x18/0x60
          process_backlog+0xa8/0x150
@@ -1115,7 +1115,7 @@ Extended error information
          inet_sendmsg+0x64/0xa0
          sock_sendmsg+0x3d/0x50
     } hitcount:        115  len:      13030
-    { stacktrace:
+    { common_stacktrace:
          __netif_receive_skb_core+0x46d/0x990
          __netif_receive_skb+0x18/0x60
          netif_receive_skb_internal+0x23/0x90
@@ -1142,14 +1142,14 @@ Extended error information
   into the histogram.  In order to avoid having to set everything up
   again, we can just clear the histogram first::
 
-    # echo 'hist:key=stacktrace:vals=len:clear' >> \
+    # echo 'hist:key=common_stacktrace:vals=len:clear' >> \
            /sys/kernel/tracing/events/net/netif_receive_skb/trigger
 
   Just to verify that it is in fact cleared, here's what we now see in
   the hist file::
 
     # cat /sys/kernel/tracing/events/net/netif_receive_skb/hist
-    # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused]
+    # trigger info: hist:keys=common_stacktrace:vals=len:sort=hitcount:size=2048 [paused]
 
     Totals:
         Hits: 0
@@ -1485,12 +1485,12 @@ Extended error information
 
   And here's an example that shows how to combine histogram data from
   any two events even if they don't share any 'compatible' fields
-  other than 'hitcount' and 'stacktrace'.  These commands create a
+  other than 'hitcount' and 'common_stacktrace'.  These commands create a
   couple of triggers named 'bar' using those fields::
 
-    # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
+    # echo 'hist:name=bar:key=common_stacktrace:val=hitcount' > \
            /sys/kernel/tracing/events/sched/sched_process_fork/trigger
-    # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
+    # echo 'hist:name=bar:key=common_stacktrace:val=hitcount' > \
           /sys/kernel/tracing/events/net/netif_rx/trigger
 
   And displaying the output of either shows some interesting if
@@ -1501,16 +1501,16 @@ Extended error information
 
     # event histogram
     #
-    # trigger info: hist:name=bar:keys=stacktrace:vals=hitcount:sort=hitcount:size=2048 [active]
+    # trigger info: hist:name=bar:keys=common_stacktrace:vals=hitcount:sort=hitcount:size=2048 [active]
     #
 
-    { stacktrace:
+    { common_stacktrace:
              kernel_clone+0x18e/0x330
              kernel_thread+0x29/0x30
              kthreadd+0x154/0x1b0
              ret_from_fork+0x3f/0x70
     } hitcount:          1
-    { stacktrace:
+    { common_stacktrace:
              netif_rx_internal+0xb2/0xd0
              netif_rx_ni+0x20/0x70
              dev_loopback_xmit+0xaa/0xd0
@@ -1528,7 +1528,7 @@ Extended error information
              call_cpuidle+0x3b/0x60
              cpu_startup_entry+0x22d/0x310
     } hitcount:          1
-    { stacktrace:
+    { common_stacktrace:
              netif_rx_internal+0xb2/0xd0
              netif_rx_ni+0x20/0x70
              dev_loopback_xmit+0xaa/0xd0
@@ -1543,7 +1543,7 @@ Extended error information
              SyS_sendto+0xe/0x10
              entry_SYSCALL_64_fastpath+0x12/0x6a
     } hitcount:          2
-    { stacktrace:
+    { common_stacktrace:
              netif_rx_internal+0xb2/0xd0
              netif_rx+0x1c/0x60
              loopback_xmit+0x6c/0xb0
@@ -1561,7 +1561,7 @@ Extended error information
              sock_sendmsg+0x38/0x50
              ___sys_sendmsg+0x14e/0x270
     } hitcount:         76
-    { stacktrace:
+    { common_stacktrace:
              netif_rx_internal+0xb2/0xd0
              netif_rx+0x1c/0x60
              loopback_xmit+0x6c/0xb0
@@ -1579,7 +1579,7 @@ Extended error information
              sock_sendmsg+0x38/0x50
              ___sys_sendmsg+0x269/0x270
     } hitcount:         77
-    { stacktrace:
+    { common_stacktrace:
              netif_rx_internal+0xb2/0xd0
              netif_rx+0x1c/0x60
              loopback_xmit+0x6c/0xb0
@@ -1597,7 +1597,7 @@ Extended error information
              sock_sendmsg+0x38/0x50
              SYSC_sendto+0xef/0x170
     } hitcount:         88
-    { stacktrace:
+    { common_stacktrace:
              kernel_clone+0x18e/0x330
              SyS_clone+0x19/0x20
              entry_SYSCALL_64_fastpath+0x12/0x6a
@@ -1949,7 +1949,7 @@ uninterruptible state::
 
   # cd /sys/kernel/tracing
   # echo 's:block_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events
-  # echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace  if prev_state == 2' >> events/sched/sched_switch/trigger
+  # echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=common_stacktrace  if prev_state == 2' >> events/sched/sched_switch/trigger
   # echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,s=$st:onmax($delta).trace(block_lat,prev_pid,$delta,$s)' >> events/sched/sched_switch/trigger
   # echo 1 > events/synthetic/block_lat/enable
   # cat trace