linux-stable.git/kernel/perf_event.c, branch master

perf: Start the restructuring

2011-05-03T10:59:43+00:00

mv kernel/perf_event.c -> kernel/events/core.c. From there, all further
sensible splitting can happen. The idea is that due to perf_event.c
becoming pretty sizable and with the advent of the marriage with ftrace,
splitting functionality into its logical parts should help speeding up
the unification and to manage the complexity of the subsystem.

Signed-off-by: Borislav Petkov

Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core

2011-04-27T08:40:21+00:00

Conflicts:
	include/linux/perf_event.h

Merge reason: pick up the latest jump-label enhancements, they are cooked ready.

Signed-off-by: Ingo Molnar

perf_event: Fix cgrp event scheduling bug in perf_enable_on_exec()

2011-04-11T09:07:55+00:00

There is a bug in perf_event_enable_on_exec() when cgroup events are
active on a CPU: the cgroup events may be scheduled twice causing event
state corruptions which eventually may lead to kernel panics.

The reason is that the function needs to first schedule out the cgroup
events, just like for the per-thread events. The cgroup event are
scheduled back in automatically from the perf_event_context_sched_in()
function.

The patch also adds a WARN_ON_ONCE() is perf_cgroup_switch() to catch any
bogus state.

Signed-off-by: Stephane Eranian 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20110406005454.GA1062@quad
Signed-off-by: Ingo Molnar

jump label: Introduce static_branch() interface

2011-04-04T16:48:08+00:00

Introduce:

static __always_inline bool static_branch(struct jump_label_key *key);

instead of the old JUMP_LABEL(key, label) macro.

In this way, jump labels become really easy to use:

Define:

        struct jump_label_key jump_key;

Can be used as:

        if (static_branch(&jump_key))
                do unlikely code

enable/disale via:

        jump_label_inc(&jump_key);
        jump_label_dec(&jump_key);

that's it!

For the jump labels disabled case, the static_branch() becomes an
atomic_read(), and jump_label_inc()/dec() are simply atomic_inc(),
atomic_dec() operations. We show testing results for this change below.

Thanks to H. Peter Anvin for suggesting the 'static_branch()' construct.

Since we now require a 'struct jump_label_key *key', we can store a pointer into
the jump table addresses. In this way, we can enable/disable jump labels, in
basically constant time. This change allows us to completely remove the previous
hashtable scheme. Thanks to Peter Zijlstra for this re-write.

Testing:

I ran a series of 'tbench 20' runs 5 times (with reboots) for 3
configurations, where tracepoints were disabled.

jump label configured in
avg: 815.6

jump label *not* configured in (using atomic reads)
avg: 800.1

jump label *not* configured in (regular reads)
avg: 803.4

Signed-off-by: Peter Zijlstra 
LKML-Reference: <20110316212947.GA8792@redhat.com>
Signed-off-by: Jason Baron 
Suggested-by: H. Peter Anvin 
Tested-by: David Daney 
Acked-by: Ralf Baechle 
Acked-by: David S. Miller 
Acked-by: Mathieu Desnoyers 
Signed-off-by: Steven Rostedt

perf: Fix task_struct reference leak

2011-03-31T11:02:56+00:00

sys_perf_event_open() had an imbalance in the number of task refs it
took causing memory leakage

Cc: Jiri Olsa 
Cc: Oleg Nesterov 
Cc: stable@kernel.org # .37+
Signed-off-by: Peter Zijlstra 
LKML-Reference: 
Signed-off-by: Ingo Molnar

perf: Rebase max unprivileged mlock threshold on top of page size

2011-03-31T11:02:54+00:00

Ensure we allow 512 kiB + 1 page for user control without
assuming a 4096 bytes page size.

Reported-by: Peter Zijlstra 
Signed-off-by: Frederic Weisbecker 
Signed-off-by: Peter Zijlstra 
Cc: Arnaldo Carvalho de Melo 
Cc: Paul Mackerras 
Cc: Stephane Eranian 
Cc: 
LKML-Reference: <1301535209-9679-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar

perf: Better fit max unprivileged mlock pages for tools needs

2011-03-23T19:57:04+00:00

The maximum kilobytes of locked memory that an unprivileged user
can reserve is of 512 kB = 128 pages by default, scaled to the
number of onlined CPUs, which fits well with the tools that use
128 data pages by default.

However tools actually use 129 pages, because they need one more
for the user control page. Thus the default mlock threshold is
not sufficient for the default tools needs and we always end up
to evaluate the constant mlock rlimit policy, which doesn't have
this scaling with the number of online CPUs.

Hence, on systems that have more than 16 CPUs, we overlap the
rlimit threshold and fail to mmap:

	$ perf record ls
	Error: failed to mmap with 1 (Operation not permitted)

Just increase the max unprivileged mlock threshold by one page
so that it supports well perf tools even after 16 CPUs.

Reported-by: Han Pingtian 
Reported-by: Peter Zijlstra 
Reported-by: Arnaldo Carvalho de Melo 
Signed-off-by: Frederic Weisbecker 
Acked-by: Arnaldo Carvalho de Melo 
Cc: Stephane Eranian 
Cc: Stable 
LKML-Reference: <1300904979-5508-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar

perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx()

2011-03-23T15:07:22+00:00

This patch solves a stale pointer problem in
update_cgrp_time_from_cpuctx(). The cpuctx->cgrp
was not cleared on all possible event exit paths,
including:

   close()
     perf_release()
       perf_release_kernel()
         list_del_event()

This patch fixes list_del_event() to clear cpuctx->cgrp
when there are no cgroup events left in the context.

[ This second version makes the code compile when
  CONFIG_CGROUP_PERF is not enabled. We unconditionally define
  perf_cpu_context->cgrp. ]

Signed-off-by: Stephane Eranian 
Cc: peterz@infradead.org
Cc: perfmon2-devel@lists.sf.net
Cc: paulus@samba.org
Cc: davem@davemloft.net
LKML-Reference: <20110323150306.GA1580@quad>
Signed-off-by: Ingo Molnar

perf: Fix tear-down of inherited group events

2011-03-16T13:04:14+00:00

When destroying inherited events, we need to destroy groups too,
otherwise the event iteration in perf_event_exit_task_context() will
miss group siblings and we leak events with all the consequences.

Reported-and-tested-by: Vince Weaver 
Signed-off-by: Peter Zijlstra 
Cc:  # .35+
LKML-Reference: <1300196470.2203.61.camel@twins>
Signed-off-by: Ingo Molnar

perf: Handle stopped state with tracepoints

2011-03-16T13:04:14+00:00

We toggle the state from start and stop callbacks but actually
don't check it when the event triggers. Do it so that
these callbacks actually work.

Signed-off-by: Frederic Weisbecker 
Cc: Arnaldo Carvalho de Melo 
Cc: Paul Mackerras 
Cc: Stephane Eranian 
Cc: 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1299529629-18280-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar