As Miklos reported and suggested:

 "This pattern repeats two times in trace_uprobe.c and in
  kernel/events/core.c as well:

      ret = kern_path(filename, LOOKUP_FOLLOW, &path);
      if (ret)
          goto fail_address_parse;

      inode = igrab(d_inode(path.dentry));
      path_put(&path);

  And it's wrong.  You can only hold a reference to the inode if you
  have an active ref to the superblock as well (which is normally
  through path.mnt) or holding s_umount.

  This way unmounting the containing filesystem while the tracepoint is
  active will give you the "VFS: Busy inodes after unmount..." message
  and a crash when the inode is finally put.

  Solution: store path instead of inode."

This patch fixes the issue in kernel/event/core.c.
Reviewed-and-tested-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@fb.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 375637bc ("perf/core: Introduce address range filtering")
Link: http://lkml.kernel.org/r/20180418062907.3210386-2-songliubraving@fb.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When hw and sw events are mixed in the same group, they are all attached
to the hw perf_event_context. This sometimes requires moving group of
perf_event to a different context.

We found a bug in how the kernel handles this, for example if we do:

   perf stat -e '{faults,ref-cycles,faults}'  -I 1000

     1.005591180              1,297      faults
     1.005591180        457,476,576      ref-cycles
     1.005591180    <not supported>      faults

First, sw event "faults" is attached to the sw context, and becomes the
group leader. Then, hw event "ref-cycles" is attached, so both events
are moved to the hw context. Last, another sw "faults" tries to attach,
but it fails because of mismatch between the new target ctx (from sw
pmu) and the group_leader's ctx (hw context, same as ref-cycles).

The broken condition is:
   group_leader is sw event;
   group_leader is on hw context;
   add a sw event to the group.

Fix this scenario by checking group_leader's context (instead of just
event type). If group_leader is on hw context, use the ->pmu of this
context to look up context for the new event.
Signed-off-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@fb.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: b04243ef ("perf: Complete software pmu grouping")
Link: http://lkml.kernel.org/r/20180503194716.162815-1-songliubraving@fb.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

This is a cosmetic patch that deals with the address filter structure's
ambiguous fields 'filter' and 'range'. The former stands to mean that the
filter's *action* should be to filter the traces to its address range if
it's set or stop tracing if it's unset. This is confusing and hard on the
eyes, so this patch replaces it with 'action' enum. The 'range' field is
completely redundant (meaning that the filter is an address range as
opposed to a single address trigger), as we can use zero size to mean the
same thing.
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180329120648.11902-1-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Mark noticed that the change to sibling_list changed some iteration
semantics; because previously we used group_list as list entry,
sibling events would always have an empty sibling_list.

But because we now use sibling_list for both list head and list entry,
siblings will report as having siblings.

Fix this with a custom for_each_sibling_event() iterator.

Fixes: 8343aae6 ("perf/core: Remove perf_event::group_entry")
Reported-by: NMark Rutland <mark.rutland@arm.com>
Suggested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: vincent.weaver@maine.edu
Cc: alexander.shishkin@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: alexey.budankov@linux.intel.com
Cc: valery.cherepennikov@intel.com
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Cc: davidcc@google.com
Cc: kan.liang@intel.com
Cc: Dmitry.Prohorov@intel.com
Cc: jolsa@redhat.com
Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net

Mark noticed that the change to sibling_list changed some iteration
semantics; because previously we used group_list as list entry,
sibling events would always have an empty sibling_list.

But because we now use sibling_list for both list head and list entry,
siblings will report as having siblings.

Fix this with a custom for_each_sibling_event() iterator.

Fixes: 8343aae6 ("perf/core: Remove perf_event::group_entry")
Reported-by: NMark Rutland <mark.rutland@arm.com>
Suggested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: vincent.weaver@maine.edu
Cc: alexander.shishkin@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: alexey.budankov@linux.intel.com
Cc: valery.cherepennikov@intel.com
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Cc: davidcc@google.com
Cc: kan.liang@intel.com
Cc: Dmitry.Prohorov@intel.com
Cc: jolsa@redhat.com
Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net

When an event group contains more events than can be scheduled on the
hardware, iterating the full event group for ctx_sched_out is a waste
of time.

Keep track of the events that got programmed on the hardware, such
that we can iterate this smaller list in order to schedule them out.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Now that all the grouping is done with RB trees, we no longer need
group_entry and can replace the whole thing with sibling_list.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Change event groups into RB trees sorted by CPU and then by a 64bit
index, so that multiplexing hrtimer interrupt handler would be able
skipping to the current CPU's list and ignore groups allocated for the
other CPUs.

New API for manipulating event groups in the trees is implemented as well
as adoption on the API in the current implementation.

pinned_group_sched_in() and flexible_group_sched_in() API are
introduced to consolidate code enabling the whole group from pinned
and flexible groups appropriately.
Signed-off-by: NAlexey Budankov <alexey.budankov@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/372f9c8b-0cfe-4240-e44d-83d863d40813@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit 0515e599 ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT
program type") introduced the bpf_perf_event_data structure which
exports the pt_regs structure.  This is OK for multiple architectures
but fail for s390 and arm64 which do not export pt_regs.  Programs
using them, for example, the bpf selftest fail to compile on these
architectures.

For s390, exporting the pt_regs is not an option because s390 wants
to allow changes to it.  For arm64, there is a user_pt_regs structure
that covers parts of the pt_regs structure for use by user space.

To solve the broken uapi for s390 and arm64, introduce an abstract
type for pt_regs and add an asm/bpf_perf_event.h file that concretes
the type.  An asm-generic header file covers the architectures that
export pt_regs today.

The arch-specific enablement for s390 and arm64 follows in separate
commits.
Reported-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
Fixes: 0515e599 ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type")
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The current even timekeeping, which computes enabled and running
times, uses 3 distinct timestamps to reflect the various event states:
OFF (stopped), INACTIVE (enabled) and ACTIVE (running).

Furthermore, the update rules are such that even INACTIVE events need
their timestamps updated. This is undesirable because we'd like to not
touch INACTIVE events if at all possible, this makes event scheduling
(much) more expensive than needed.

Rewrite the timekeeping to directly use event->state, this greatly
simplifies the code and results in only having to update things when
we change state, or an up-to-date value is requested (read).
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Its a weird name, active is one of the states, it should not be part
of the name, also, its too long.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

perf/bpf: Extend the perf_event_read_local() interface, a.k.a. "bpf: perf event change needed for subsequent bpf helpers"

eBPF programs would like access to the (perf) event enabled and
running times along with the event value, such that they can deal with
event multiplexing (among other things).

This patch extends the interface; a future eBPF patch will utilize
the new functionality.

[ Note, there's a same-content commit with a poor changelog and a meaningless
  title in the networking tree as well - but we need this change for subsequent
  perf work, so apply it here as well, with a proper changelog. Hopefully Git
  will be able to sort out this somewhat messy workflow, if there are no other,
  conflicting changes to these files. ]
Signed-off-by: NYonghong Song <yhs@fb.com>
[ Rewrote the changelog. ]
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: <ast@fb.com>
Cc: <daniel@iogearbox.net>
Cc: <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20171005161923.332790-2-yhs@fb.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Revert commit:

  75e83876 ("perf/ftrace: Fix double traces of perf on ftrace:function")

The reason I instantly stumbled on that patch is that it only addresses the
ftrace situation and doesn't mention the other _5_ places that use this
interface. It doesn't explain why those don't have the problem and if not, why
their solution doesn't work for ftrace.

It doesn't, but this is just putting more duct tape on.

Link: http://lkml.kernel.org/r/20171011080224.200565770@infradead.org

Cc: Zhou Chengming <zhouchengming1@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

This patch does not impact existing functionalities.
It contains the changes in perf event area needed for
subsequent bpf_perf_event_read_value and
bpf_perf_prog_read_value helpers.
Signed-off-by: NYonghong Song <yhs@fb.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For understanding how the workload maps to memory channels and hardware
behavior, it's very important to collect address maps with physical
addresses. For example, 3D XPoint access can only be found by filtering
the physical address.

Add a new sample type for physical address.

perf already has a facility to collect data virtual address. This patch
introduces a function to convert the virtual address to physical address.
The function is quite generic and can be extended to any architecture as
long as a virtual address is provided.

 - For kernel direct mapping addresses, virt_to_phys is used to convert
   the virtual addresses to physical address.

 - For user virtual addresses, __get_user_pages_fast is used to walk the
   pages tables for user physical address.

 - This does not work for vmalloc addresses right now. These are not
   resolved, but code to do that could be added.

The new sample type requires collecting the virtual address. The
virtual address will not be output unless SAMPLE_ADDR is applied.

For security, the physical address can only be exposed to root or
privileged user.
Tested-by: NMadhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: NKan Liang <kan.liang@intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: mpe@ellerman.id.au
Link: http://lkml.kernel.org/r/1503967969-48278-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

I just noticed that hw.itrace_started and hw.config are aliased to the
same location. Now, the PT driver happens to use both, which works out
fine by sheer luck:

 - STORE(hw.itrace_start) is ordered before STORE(hw.config), in the
    program order, although there are no compiler barriers to ensure that,

 - to the perf_log_itrace_start() hw.itrace_start looks set at the same
   time as when it is intended to be set because both stores happen in the
   same path,

 - hw.config is never reset to zero in the PT driver.

Now, the use of hw.config by the PT driver makes more sense (it being a
HW PMU) than messing around with itrace_started, which is an awkward API
to begin with.

This patch replaces hw.itrace_started with an attach_state bit and an
API call for the PMU drivers to use to communicate the condition.
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20170330153956.25994-1-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When running perf on the ftrace:function tracepoint, there is a bug
which can be reproduced by:

  perf record -e ftrace:function -a sleep 20 &
  perf record -e ftrace:function ls
  perf script

              ls 10304 [005]   171.853235: ftrace:function:
  perf_output_begin
              ls 10304 [005]   171.853237: ftrace:function:
  perf_output_begin
              ls 10304 [005]   171.853239: ftrace:function:
  task_tgid_nr_ns
              ls 10304 [005]   171.853240: ftrace:function:
  task_tgid_nr_ns
              ls 10304 [005]   171.853242: ftrace:function:
  __task_pid_nr_ns
              ls 10304 [005]   171.853244: ftrace:function:
  __task_pid_nr_ns

We can see that all the function traces are doubled.

The problem is caused by the inconsistency of the register
function perf_ftrace_event_register() with the probe function
perf_ftrace_function_call(). The former registers one probe
for every perf_event. And the latter handles all perf_events
on the current cpu. So when two perf_events on the current cpu,
the traces of them will be doubled.

So this patch adds an extra parameter "event" for perf_tp_event,
only send sample data to this event when it's not NULL.
Signed-off-by: NZhou Chengming <zhouchengming1@huawei.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: huawei.libin@huawei.com
Link: http://lkml.kernel.org/r/1503668977-12526-1-git-send-email-zhouchengming1@huawei.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Vince reported the following rdpmc() testcase failure:

 > Failing test case:
 >
 >	fd=perf_event_open();
 >	addr=mmap(fd);
 >	exec()  // without closing or unmapping the event
 >	fd=perf_event_open();
 >	addr=mmap(fd);
 >	rdpmc()	// GPFs due to rdpmc being disabled

The problem is of course that exec() plays tricks with what is
current->mm, only destroying the old mappings after having
installed the new mm.

Fix this confusion by passing along vma->vm_mm instead of relying on
current->mm.
Reported-by: NVince Weaver <vincent.weaver@maine.edu>
Tested-by: NVince Weaver <vincent.weaver@maine.edu>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 1e0fb9ec ("perf: Add pmu callbacks to track event mapping and unmapping")
Link: http://lkml.kernel.org/r/20170802173930.cstykcqefmqt7jau@hirez.programming.kicks-ass.net
[ Minor cleanups. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

'perf cqm' never worked due to the incompatibility between perf
infrastructure and cqm hardware support.  The hardware uses RMIDs to
track the llc occupancy of tasks and these RMIDs are per package. This
makes monitoring a hierarchy like cgroup along with monitoring of tasks
separately difficult and several patches sent to lkml to fix them were
NACKed. Further more, the following issues in the current perf cqm make
it almost unusable:

    1. No support to monitor the same group of tasks for which we do
    allocation using resctrl.

    2. It gives random and inaccurate data (mostly 0s) once we run out
    of RMIDs due to issues in Recycling.

    3. Recycling results in inaccuracy of data because we cannot
    guarantee that the RMID was stolen from a task when it was not
    pulling data into cache or even when it pulled the least data. Also
    for monitoring llc_occupancy, if we stop using an RMID_x and then
    start using an RMID_y after we reclaim an RMID from an other event,
    we miss accounting all the occupancy that was tagged to RMID_x at a
    later perf_count.

    2. Recycling code makes the monitoring code complex including
    scheduling because the event can lose RMID any time. Since MBM
    counters count bandwidth for a period of time by taking snap shot of
    total bytes at two different times, recycling complicates the way we
    count MBM in a hierarchy. Also we need a spin lock while we do the
    processing to account for MBM counter overflow. We also currently
    use a spin lock in scheduling to prevent the RMID from being taken
    away.

    4. Lack of support when we run different kind of event like task,
    system-wide and cgroup events together. Data mostly prints 0s. This
    is also because we can have only one RMID tied to a cpu as defined
    by the cqm hardware but a perf can at the same time tie multiple
    events during one sched_in.

    5. No support of monitoring a group of tasks. There is partial support
    for cgroup but it does not work once there is a hierarchy of cgroups
    or if we want to monitor a task in a cgroup and the cgroup itself.

    6. No support for monitoring tasks for the lifetime without perf
    overhead.

    7. It reported the aggregate cache occupancy or memory bandwidth over
    all sockets. But most cloud and VMM based use cases want to know the
    individual per-socket usage.
Signed-off-by: NVikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: davidcc@google.com
Cc: reinette.chatre@intel.com
Link: http://lkml.kernel.org/r/1501017287-28083-2-git-send-email-vikas.shivappa@linux.intel.com

Allow BPF_PROG_TYPE_PERF_EVENT program types to attach to all
perf_event types, including HW_CACHE, RAW, and dynamic pmu events.
Only tracepoint/kprobe events are treated differently which require
BPF_PROG_TYPE_TRACEPOINT/BPF_PROG_TYPE_KPROBE program types accordingly.

Also add support for reading all event counters using
bpf_perf_event_read() helper.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

perf, tracing, kprobes and jump_labels have a gazillion of ways to create
dependency lock chains. Some of those involve nested invocations of
get_online_cpus().

The conversion of the hotplug locking to a percpu rwsem requires to avoid
such nested calls. sys_perf_event_open() protects most of the syscall logic
against cpu hotplug. This causes nested calls and lock inversions versus
ftrace and kprobes in various interesting ways.

It's impossible to move the hotplug locking to the outer end of all call
chains in the involved facilities, so the hotplug protection in
sys_perf_event_open() needs to be solved differently.

Introduce 'pmus_mutex' which protects a perf private online cpumask. This
mutex is taken when the mask is updated in the cpu hotplug callbacks and
can be taken in sys_perf_event_open() to protect the swhash setup/teardown
code and when the final judgement about a valid event has to be made.

[ tglx: Produced changelog and fixed the swhash interaction ]
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/20170524081548.930941109@linutronix.de

Current AMD IOMMU perf PMU inappropriately uses the hardware struct
inside the union in struct hw_perf_event, extra_reg in particular.

Instead, introduce an AMD IOMMU-specific struct with required parameters
to be programmed into the IOMMU performance counter control register.

Update the pasid field from 16 to 20 bits while at it.
Signed-off-by: NSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
[ Fixup macros, shorten get_next_avail_iommu_bnk_cntr() local vars, massage commit message. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jörg Rödel <joro@8bytes.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/1487926102-13073-10-git-send-email-Suravee.Suthikulpanit@amd.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

In preparation for adding more flags to perf AUX records, introduce a
separate API for setting the flags for a session, rather than appending
more bool arguments to perf_aux_output_end. This allows to set each
flag at the time a corresponding condition is detected, instead of
tracking it in each driver's private state.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20170220133352.17995-3-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

With the advert of container technologies like docker, that depend on
namespaces for isolation, there is a need for tracing support for
namespaces. This patch introduces new PERF_RECORD_NAMESPACES event for
recording namespaces related info. By recording info for every
namespace, it is left to userspace to take a call on the definition of a
container and trace containers by updating perf tool accordingly.

Each namespace has a combination of device and inode numbers. Though
every namespace has the same device number currently, that may change in
future to avoid the need for a namespace of namespaces. Considering such
possibility, record both device and inode numbers separately for each
namespace.
Signed-off-by: NHari Bathini <hbathini@linux.vnet.ibm.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/148891929686.25309.2827618988917007768.stgit@hbathini.in.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

While supporting file-based address filters for CPU events requires some
extra context switch handling, kernel address filters are easy, since the
kernel mapping is preserved across address spaces. It is also useful as
it permits tracing scheduling paths of the kernel.

This patch allows setting up kernel filters for CPU events.
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20170126094057.13805-4-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

cpuctx->unique_pmu was originally introduced as a way to identify cpuctxs
with shared pmus in order to avoid visiting the same cpuctx more than once
in a for_each_pmu loop.

cpuctx->unique_pmu == cpuctx->pmu in non-software task contexts since they
have only one pmu per cpuctx. Since perf_pmu_sched_task() is only called in
hw contexts, this patch replaces cpuctx->unique_pmu by cpuctx->pmu in it.

The change above, together with the previous patch in this series, removed
the remaining uses of cpuctx->unique_pmu, so we remove it altogether.
Signed-off-by: NDavid Carrillo-Cisneros <davidcc@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: Vince Weaver <vince@deater.net>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20170118192454.58008-3-davidcc@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

This patch follows from a conversation in CQM/CMT's last series about
speeding up the context switch for cgroup events:

  https://patchwork.kernel.org/patch/9478617/

This is a low-hanging fruit optimization. It replaces the iteration over
the "pmus" list in cgroup switch by an iteration over a new list that
contains only cpuctxs with at least one cgroup event.

This is necessary because the number of PMUs have increased over the years
e.g modern x86 server systems have well above 50 PMUs.

The iteration over the full PMU list is unneccessary and can be costly in
heavy cache contention scenarios.

Below are some instrumentation measurements with 10, 50 and 90 percentiles
of the total cost of context switch before and after this optimization for
a simple array read/write microbenchark.

  Contention
    Level    Nr events      Before (us)            After (us)       Median
  L2    L3     types      (10%, 50%, 90%)       (10%, 50%, 90%     Speedup
  --------------------------------------------------------------------------
  Low   Low       1       (1.72, 2.42, 5.85)    (1.35, 1.64, 5.46)     29%
  High  Low       1       (2.08, 4.56, 19.8)    (1720, 2.20, 13.7)     51%
  High  High      1       (2.86, 10.4, 12.7)    (2.54, 4.32, 12.1)     58%

  Low   Low       2       (1.98, 3.20, 6.89)    (1.68, 2.41, 8.89)     24%
  High  Low       2       (2.48, 5.28, 22.4)    (2150, 3.69, 14.6)     30%
  High  High      2       (3.32, 8.09, 13.9)    (2.80, 5.15, 13.7)     36%

where:

  1 event type  = cycles
  2 event types = cycles,intel_cqm/llc_occupancy/

   Contention L2 Low: workset  <  L2 cache size.
                 High:  "     >>  L2   "     " .
   Contention L3 Low: workset of task on all sockets  <  L3 cache size.
                 High:   "     "   "   "   "    "    >>  L3   "     " .

   Median Speedup is (50%ile Before - 50%ile After) /  50%ile Before

Unsurprisingly, the benefits of this optimization decrease with the number
of cpuctxs with a cgroup events, yet, is never detrimental.
Tested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NDavid Carrillo-Cisneros <davidcc@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: Vince Weaver <vince@deater.net>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20170118192454.58008-2-davidcc@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

It's possible to set up PEBS events to get only errors and not
any data, like on SNB-X (model 45) and IVB-EP (model 62)
via 2 perf commands running simultaneously:

    taskset -c 1 ./perf record -c 4 -e branches:pp -j any -C 10

This leads to a soft lock up, because the error path of the
intel_pmu_drain_pebs_nhm() does not account event->hw.interrupt
for error PEBS interrupts, so in case you're getting ONLY
errors you don't have a way to stop the event when it's over
the max_samples_per_tick limit:

  NMI watchdog: BUG: soft lockup - CPU#22 stuck for 22s! [perf_fuzzer:5816]
  ...
  RIP: 0010:[<ffffffff81159232>]  [<ffffffff81159232>] smp_call_function_single+0xe2/0x140
  ...
  Call Trace:
   ? trace_hardirqs_on_caller+0xf5/0x1b0
   ? perf_cgroup_attach+0x70/0x70
   perf_install_in_context+0x199/0x1b0
   ? ctx_resched+0x90/0x90
   SYSC_perf_event_open+0x641/0xf90
   SyS_perf_event_open+0x9/0x10
   do_syscall_64+0x6c/0x1f0
   entry_SYSCALL64_slow_path+0x25/0x25

Add perf_event_account_interrupt() which does the interrupt
and frequency checks and call it from intel_pmu_drain_pebs_nhm()'s
error path.

We keep the pending_kill and pending_wakeup logic only in the
__perf_event_overflow() path, because they make sense only if
there's any data to deliver.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vince@deater.net>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1482931866-6018-2-git-send-email-jolsa@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The trinity syscall fuzzer triggered following WARN() on powerpc:

  WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278
  ...
  NIP [c00000000093aedc] .hw_breakpoint_handler+0x28c/0x2b0
  LR [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0
  Call Trace:
  [c0000002f7933580] [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 (unreliable)
  [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0
  [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0
  [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0
  [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100
  [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48

Followed by a lockdep warning:

  ===============================
  [ INFO: suspicious RCU usage. ]
  4.8.0-rc5+ #7 Tainted: G        W
  -------------------------------
  ./include/linux/rcupdate.h:556 Illegal context switch in RCU read-side critical section!

  other info that might help us debug this:

  rcu_scheduler_active = 1, debug_locks = 0
  2 locks held by ls/2998:
   #0:  (rcu_read_lock){......}, at: [<c0000000000f6a00>] .__atomic_notifier_call_chain+0x0/0x1c0
   #1:  (rcu_read_lock){......}, at: [<c00000000093ac50>] .hw_breakpoint_handler+0x0/0x2b0

  stack backtrace:
  CPU: 9 PID: 2998 Comm: ls Tainted: G        W       4.8.0-rc5+ #7
  Call Trace:
  [c0000002f7933150] [c00000000094b1f8] .dump_stack+0xe0/0x14c (unreliable)
  [c0000002f79331e0] [c00000000013c468] .lockdep_rcu_suspicious+0x138/0x180
  [c0000002f7933270] [c0000000001005d8] .___might_sleep+0x278/0x2e0
  [c0000002f7933300] [c000000000935584] .mutex_lock_nested+0x64/0x5a0
  [c0000002f7933410] [c00000000023084c] .perf_event_ctx_lock_nested+0x16c/0x380
  [c0000002f7933500] [c000000000230a80] .perf_event_disable+0x20/0x60
  [c0000002f7933580] [c00000000093aeec] .hw_breakpoint_handler+0x29c/0x2b0
  [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0
  [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0
  [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0
  [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100
  [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48

While it looks like the first WARN() is probably valid, the other one is
triggered by disabling event via perf_event_disable() from atomic context.

The event is disabled here in case we were not able to emulate
the instruction that hit the breakpoint. By disabling the event
we unschedule the event and make sure it's not scheduled back.

But we can't call perf_event_disable() from atomic context, instead
we need to use the event's pending_disable irq_work method to disable it.
Reported-by: NJan Stancek <jstancek@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161026094824.GA21397@kravaSigned-off-by: NIngo Molnar <mingo@kernel.org>

Allow attaching BPF_PROG_TYPE_PERF_EVENT programs to sw and hw perf events
via overflow_handler mechanism.
When program is attached the overflow_handlers become stacked.
The program acts as a filter.
Returning zero from the program means that the normal perf_event_output handler
will not be called and sampling event won't be stored in the ring buffer.

The overflow_handler_context==NULL is an additional safety check
to make sure programs are not attached to hw breakpoints and watchdog
in case other checks (that prevent that now anyway) get accidentally
relaxed in the future.

The program refcnt is incremented in case perf_events are inhereted
when target task is forked.
Similar to kprobe and tracepoint programs there is no ioctl to
detach the program or swap already attached program. The user space
expected to close(perf_event_fd) like it does right now for kprobe+bpf.
That restriction simplifies the code quite a bit.

The invocation of overflow_handler in __perf_event_overflow() is now
done via READ_ONCE, since that pointer can be replaced when the program
is attached while perf_event itself could have been active already.
There is no need to do similar treatment for event->prog, since it's
assigned only once before it's accessed.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce BPF_PROG_TYPE_PERF_EVENT programs that can be attached to
HW and SW perf events (PERF_TYPE_HARDWARE and PERF_TYPE_SOFTWARE
correspondingly in uapi/linux/perf_event.h)

The program visible context meta structure is
struct bpf_perf_event_data {
    struct pt_regs regs;
     __u64 sample_period;
};
which is accessible directly from the program:
int bpf_prog(struct bpf_perf_event_data *ctx)
{
  ... ctx->sample_period ...
  ... ctx->regs.ip ...
}

The bpf verifier rewrites the accesses into kernel internal
struct bpf_perf_event_data_kern which allows changing
struct perf_sample_data without affecting bpf programs.
New fields can be added to the end of struct bpf_perf_event_data
in the future.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce the flag PMU_EV_CAP_READ_ACTIVE_PKG, useful for uncore events,
that allows a PMU to signal the generic perf code that an event is readable
in the current CPU if the event is active in a CPU in the same package as
the current CPU.

This is an optimization that avoids a unnecessary IPI for the common case
where uncore events are run and read in the same package but in
different CPUs.

As an example, the IPI removal speeds up perf_read() in my Haswell system
as follows:

  - For event UNC_C_LLC_LOOKUP: From 260 us to 31 us.
  - For event RAPL's power/energy-cores/: From to 255 us to 27 us.

For the optimization to work, all events in the group must have it
(similarly to PERF_EV_CAP_SOFTWARE).
Signed-off-by: NDavid Carrillo-Cisneros <davidcc@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1471467307-61171-4-git-send-email-davidcc@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently, PERF_GROUP_SOFTWARE is used in the group_flags field of a
group's leader to indicate that is_software_event(event) is true for all
events in a group. This is the only usage of event->group_flags.

This pattern of setting a group level flags when all events in the group
share a property is useful for the flag introduced in the next patch and
for future CQM/CMT flags. So this patches generalizes group_flags to work
as an aggregate of event level flags.

PERF_GROUP_SOFTWARE denotes an inmutable event's property. All other flags
that I intend to add are also determinable at event initialization.
To better convey the above, this patch renames event's group_flags to
group_caps and PERF_GROUP_SOFTWARE to PERF_EV_CAP_SOFTWARE.

Individual event flags are stored in the new event->event_caps. Since the
cap flags do not change after event initialization, there is no need to
serialize event_caps. This new field is used when events are added to a
context, similarly to how PERF_GROUP_SOFTWARE and is_software_event()
worked.

Lastly, for consistency, updates is_software_event() to rely in event_cap
instead of the context index.
Signed-off-by: NDavid Carrillo-Cisneros <davidcc@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1471467307-61171-3-git-send-email-davidcc@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

For perf record -b, which requires the pmu::sched_task callback the
current code is rather expensive:

     7.68%  sched-pipe  [kernel.vmlinux]    [k] perf_pmu_sched_task
     5.95%  sched-pipe  [kernel.vmlinux]    [k] __switch_to
     5.20%  sched-pipe  [kernel.vmlinux]    [k] __intel_pmu_disable_all
     3.95%  sched-pipe  perf                [.] worker_thread

The problem is that it will iterate all registered PMUs, most of which
will not have anything to do. Avoid this by keeping an explicit list
of PMUs that have requested the callback.

The perf_sched_cb_{inc,dec}() functions already takes the required pmu
argument, and now that these functions are no longer called from NMI
context we can use them to manage a list.

With this patch applied the function doesn't show up in the top 4
anymore (it dropped to 18th place).

     6.67%  sched-pipe  [kernel.vmlinux]    [k] __switch_to
     6.18%  sched-pipe  [kernel.vmlinux]    [k] __intel_pmu_disable_all
     3.92%  sched-pipe  [kernel.vmlinux]    [k] switch_mm_irqs_off
     3.71%  sched-pipe  perf                [.] worker_thread
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

There's a perf stat bug easy to observer on a machine with only one cgroup:

  $ perf stat -e cycles -I 1000 -C 0 -G /
  #          time             counts unit events
      1.000161699      <not counted>      cycles                    /
      2.000355591      <not counted>      cycles                    /
      3.000565154      <not counted>      cycles                    /
      4.000951350      <not counted>      cycles                    /

We'd expect some output there.

The underlying problem is that there is an optimization in
perf_cgroup_sched_{in,out}() that skips the switch of cgroup events
if the old and new cgroups in a task switch are the same.

This optimization interacts with the current code in two ways
that cause a CPU context's cgroup (cpuctx->cgrp) to be NULL even if a
cgroup event matches the current task. These are:

  1. On creation of the first cgroup event in a CPU: In current code,
  cpuctx->cpu is only set in perf_cgroup_sched_in, but due to the
  aforesaid optimization, perf_cgroup_sched_in will run until the next
  cgroup switches in that CPU. This may happen late or never happen,
  depending on system's number of cgroups, CPU load, etc.

  2. On deletion of the last cgroup event in a cpuctx: In list_del_event,
  cpuctx->cgrp is set NULL. Any new cgroup event will not be sched in
  because cpuctx->cgrp == NULL until a cgroup switch occurs and
  perf_cgroup_sched_in is executed (updating cpuctx->cgrp).

This patch fixes both problems by setting cpuctx->cgrp in list_add_event,
mirroring what list_del_event does when removing a cgroup event from CPU
context, as introduced in:

  commit 68cacd29 ("perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx()")

With this patch, cpuctx->cgrp is always set/clear when installing/removing
the first/last cgroup event in/from the CPU context. With cpuctx->cgrp
correctly set, event_filter_match works as intended when events are
sched in/out.

After the fix, the output is as expected:

  $ perf stat -e cycles -I 1000 -a -G /
  #         time             counts unit events
     1.004699159          627342882      cycles                    /
     2.007397156          615272690      cycles                    /
     3.010019057          616726074      cycles                    /
Signed-off-by: NDavid Carrillo-Cisneros <davidcc@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1470124092-113192-1-git-send-email-davidcc@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

This patch fixes the __output_custom() routine we currently use with
bpf_skb_copy(). I missed that when len is larger than the size of the
current handle, we can issue multiple invocations of copy_func, and
__output_custom() advances destination but also source buffer by the
written amount of bytes. When we have __output_custom(), this is actually
wrong since in that case the source buffer points to a non-linear object,
in our case an skb, which the copy_func helper is supposed to walk.
Therefore, since this is non-linear we thus need to pass the offset into
the helper, so that copy_func can use it for extracting the data from
the source object.

Therefore, adjust the callback signatures properly and pass offset
into the skb_header_pointer() invoked from bpf_skb_copy() callback. The
__DEFINE_OUTPUT_COPY_BODY() is adjusted to accommodate for two things:
i) to pass in whether we should advance source buffer or not; this is
a compile-time constant condition, ii) to pass in the offset for
__output_custom(), which we do with help of __VA_ARGS__, so everything
can stay inlined as is currently. Both changes allow for adapting the
__output_* fast-path helpers w/o extra overhead.

Fixes: 555c8a86 ("bpf: avoid stack copy and use skb ctx for event output")
Fixes: 7e3f977e ("perf, events: add non-linear data support for raw records")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for non-linear data on raw records. It
extends raw records to have one or multiple fragments that will
be written linearly into the ring slot, where each fragment can
optionally have a custom callback handler to walk and extract
complex, possibly non-linear data.

If a callback handler is provided for a fragment, then the new
__output_custom() will be used instead of __output_copy() for
the perf_output_sample() part. perf_prepare_sample() does all
the size calculation only once, so perf_output_sample() doesn't
need to redo the same work anymore, meaning real_size and padding
will be cached in the raw record. The raw record becomes 32 bytes
in size without holes; to not increase it further and to avoid
doing unnecessary recalculations in fast-path, we can reuse
next pointer of the last fragment, idea here is borrowed from
ZERO_OR_NULL_PTR(), which should keep the perf_output_sample()
path for PERF_SAMPLE_RAW minimal.

This facility is needed for BPF's event output helper as a first
user that will, in a follow-up, add an additional perf_raw_frag
to its perf_raw_record in order to be able to more efficiently
dump skb context after a linear head meta data related to it.
skbs can be non-linear and thus need a custom output function to
dump buffers. Currently, the skb data needs to be copied twice;
with the help of __output_custom() this work only needs to be
done once. Future users could be things like XDP/BPF programs
that work on different context though and would thus also have
a different callback function.

The few users of raw records are adapted to initialize their frag
data from the raw record itself, no change in behavior for them.
The code is based upon a PoC diff provided by Peter Zijlstra [1].

  [1] http://thread.gmane.org/gmane.linux.network/421294Suggested-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All users converted to state machine callbacks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAnna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153335.115333381@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Actually a nice symmetric startup/teardown pair which fits properly into
the state machine concept. In the long run we should be able to invoke
the startup callback for the boot CPU via the state machine and get
rid of the init function which invokes it on the boot CPU.

Note: This comes actually before the perf hardware callbacks. In the notifier
model the hardware callbacks have a higher priority than the core
callback. But that's solely for CPU offline so that hardware migration of
events happens before the core is notified about the outgoing CPU.

With the symetric state array model we have the following ordering:

 UP:     core -> hardware
 DOWN:   hardware -> core
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAnna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: NSebastian Siewior <bigeasy@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153333.587514098@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add a way to show different sysfs events attributes depending on
HyperThreading is on or off. This is difficult to determine
early at boot, so we just do it dynamically when the sysfs
attribute is read.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: http://lkml.kernel.org/r/1463703002-19686-3-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>