linux.git/kernel/events/core.c, branch v4.4-rc2

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-11-15T17:36:24+00:00

Pull perf updates from Thomas Gleixner:
 "Mostly updates to the perf tool plus two fixes to the kernel core code:

   - Handle tracepoint filters correctly for inherited events (Peter
     Zijlstra)

   - Prevent a deadlock in perf_lock_task_context (Paul McKenney)

   - Add missing newlines to some pr_err() calls (Arnaldo Carvalho de
     Melo)

   - Print full source file paths when using 'perf annotate --print-line
     --full-paths' (Michael Petlan)

   - Fix 'perf probe -d' when just one out of uprobes and kprobes is
     enabled (Wang Nan)

   - Add compiler.h to list.h to fix 'make perf-tar-src-pkg' generated
     tarballs, i.e. out of tree building (Arnaldo Carvalho de Melo)

   - Add the llvm-src-base.c and llvm-src-kbuild.c files, generated by
     the 'perf test' LLVM entries, when running it in-tree, to
     .gitignore (Yunlong Song)

   - libbpf error reporting improvements, using a strerror interface to
     more precisely tell the user about problems with the provided
     scriptlet, be it in C or as a ready made object file (Wang Nan)

   - Do not be case sensitive when searching for matching 'perf test'
     entries (Arnaldo Carvalho de Melo)

   - Inform the user about objdump failures in 'perf annotate' (Andi
     Kleen)

   - Improve the LLVM 'perf test' entry, introduce a new ones for BPF
     and kbuild tests to check the environment used by clang to compile
     .c scriptlets (Wang Nan)"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  perf/x86/intel/rapl: Remove the unused RAPL_EVENT_DESC() macro
  tools include: Add compiler.h to list.h
  perf probe: Verify parameters in two functions
  perf session: Add missing newlines to some pr_err() calls
  perf annotate: Support full source file paths for srcline fix
  perf test: Add llvm-src-base.c and llvm-src-kbuild.c to .gitignore
  perf: Fix inherited events vs. tracepoint filters
  perf: Disable IRQs across RCU RS CS that acquires scheduler lock
  perf test: Do not be case sensitive when searching for matching tests
  perf test: Add 'perf test BPF'
  perf test: Enhance the LLVM tests: add kbuild test
  perf test: Enhance the LLVM test: update basic BPF test program
  perf bpf: Improve BPF related error messages
  perf tools: Make fetch_kernel_version() publicly available
  bpf tools: Add new API bpf_object__get_kversion()
  bpf tools: Improve libbpf error reporting
  perf probe: Cleanup find_perf_probe_point_from_map to reduce redundancy
  perf annotate: Inform the user about objdump failures in --stdio
  perf stat: Make stat options global
  perf sched latency: Fix thread pid reuse issue
  ...

perf: Fix inherited events vs. tracepoint filters

2015-11-09T15:13:11+00:00

Arnaldo reported that tracepoint filters seem to misbehave (ie. not
apply) on inherited events.

The fix is obvious; filters are only set on the actual (parent)
event, use the normal pattern of using this parent event for filters.
This is safe because each child event has a reference to it.

Reported-by: Arnaldo Carvalho de Melo 
Tested-by: Arnaldo Carvalho de Melo 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Adrian Hunter 
Cc: Arnaldo Carvalho de Melo 
Cc: David Ahern 
Cc: Frédéric Weisbecker 
Cc: Jiri Olsa 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Cc: Wang Nan 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20151102095051.GN17308@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar

perf: Disable IRQs across RCU RS CS that acquires scheduler lock

2015-11-09T15:13:11+00:00

The perf_lock_task_context() function disables preemption across its
RCU read-side critical section because that critical section acquires
a scheduler lock.  If there was a preemption during that RCU read-side
critical section, the rcu_read_unlock() could attempt to acquire scheduler
locks, resulting in deadlock.

However, recent optimizations to expedited grace periods mean that IPI
handlers that execute during preemptible RCU read-side critical sections
can now cause the subsequent rcu_read_unlock() to acquire scheduler locks.
Disabling preemption does nothiing to prevent these IPI handlers from
executing, so these optimizations introduced a deadlock.  In theory,
this deadlock could be avoided by pulling all wakeups and printk()s out
from rnp->lock critical sections, but in practice this would re-introduce
some RCU CPU stall warning bugs.

Given that acquiring scheduler locks entails disabling interrupts, these
deadlocks can be avoided by disabling interrupts (instead of disabling
preemption) across any RCU read-side critical that acquires scheduler
locks and holds them across the rcu_read_unlock().  This commit therefore
makes this change for perf_lock_task_context().

Reported-by: Dave Jones 
Reported-by: Peter Zijlstra 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20151104134838.GR29027@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar

Merge branch 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2015-11-05T22:51:32+00:00

Pull cgroup updates from Tejun Heo:
 "The cgroup core saw several significant updates this cycle:

   - percpu_rwsem for threadgroup locking is reinstated.  This was
     temporarily dropped due to down_write latency issues.  Oleg's
     rework of percpu_rwsem which is scheduled to be merged in this
     merge window resolves the issue.

   - On the v2 hierarchy, when controllers are enabled and disabled, all
     operations are atomic and can fail and revert cleanly.  This allows
     ->can_attach() failure which is necessary for cpu RT slices.

   - Tasks now stay associated with the original cgroups after exit
     until released.  This allows tracking resources held by zombies
     (e.g.  pids) and makes it easy to find out where zombies came from
     on the v2 hierarchy.  The pids controller was broken before these
     changes as zombies escaped the limits; unfortunately, updating this
     behavior required too many invasive changes and I don't think it's
     a good idea to backport them, so the pids controller on 4.3, the
     first version which included the pids controller, will stay broken
     at least until I'm sure about the cgroup core changes.

   - Optimization of a couple common tests using static_key"

* 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (38 commits)
  cgroup: fix race condition around termination check in css_task_iter_next()
  blkcg: don't create "io.stat" on the root cgroup
  cgroup: drop cgroup__DEVEL__legacy_files_on_dfl
  cgroup: replace error handling in cgroup_init() with WARN_ON()s
  cgroup: add cgroup_subsys->free() method and use it to fix pids controller
  cgroup: keep zombies associated with their original cgroups
  cgroup: make css_set_rwsem a spinlock and rename it to css_set_lock
  cgroup: don't hold css_set_rwsem across css task iteration
  cgroup: reorganize css_task_iter functions
  cgroup: factor out css_set_move_task()
  cgroup: keep css_set and task lists in chronological order
  cgroup: make cgroup_destroy_locked() test cgroup_is_populated()
  cgroup: make css_sets pin the associated cgroups
  cgroup: relocate cgroup_[try]get/put()
  cgroup: move check_for_release() invocation
  cgroup: replace cgroup_has_tasks() with cgroup_is_populated()
  cgroup: make cgroup->nr_populated count the number of populated css_sets
  cgroup: remove an unused parameter from cgroup_task_migrate()
  cgroup: fix too early usage of static_branch_disable()
  cgroup: make cgroup_update_dfl_csses() migrate all target processes atomically
  ...

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2015-11-04T17:41:05+00:00

Pull networking updates from David Miller:

Changes of note:

 1) Allow to schedule ICMP packets in IPVS, from Alex Gartrell.

 2) Provide FIB table ID in ipv4 route dumps just as ipv6 does, from
    David Ahern.

 3) Allow the user to ask for the statistics to be filtered out of
    ipv4/ipv6 address netlink dumps.  From Sowmini Varadhan.

 4) More work to pass the network namespace context around deep into
    various packet path APIs, starting with the netfilter hooks.  From
    Eric W Biederman.

 5) Add layer 2 TX/RX checksum offloading to qeth driver, from Thomas
    Richter.

 6) Use usec resolution for SYN/ACK RTTs in TCP, from Yuchung Cheng.

 7) Support Very High Throughput in wireless MESH code, from Bob
    Copeland.

 8) Allow setting the ageing_time in switchdev/rocker.  From Scott
    Feldman.

 9) Properly autoload L2TP type modules, from Stephen Hemminger.

10) Fix and enable offload features by default in 8139cp driver, from
    David Woodhouse.

11) Support both ipv4 and ipv6 sockets in a single vxlan device, from
    Jiri Benc.

12) Fix CWND limiting of thin streams in TCP, from Bendik Rønning
    Opstad.

13) Fix IPSEC flowcache overflows on large systems, from Steffen
    Klassert.

14) Convert bridging to track VLANs using rhashtable entries rather than
    a bitmap.  From Nikolay Aleksandrov.

15) Make TCP listener handling completely lockless, this is a major
    accomplishment.  Incoming request sockets now live in the
    established hash table just like any other socket too.

    From Eric Dumazet.

15) Provide more bridging attributes to netlink, from Nikolay
    Aleksandrov.

16) Use hash based algorithm for ipv4 multipath routing, this was very
    long overdue.  From Peter Nørlund.

17) Several y2038 cures, mostly avoiding timespec.  From Arnd Bergmann.

18) Allow non-root execution of EBPF programs, from Alexei Starovoitov.

19) Support SO_INCOMING_CPU as setsockopt, from Eric Dumazet.  This
    influences the port binding selection logic used by SO_REUSEPORT.

20) Add ipv6 support to VRF, from David Ahern.

21) Add support for Mellanox Spectrum switch ASIC, from Jiri Pirko.

22) Add rtl8xxxu Realtek wireless driver, from Jes Sorensen.

23) Implement RACK loss recovery in TCP, from Yuchung Cheng.

24) Support multipath routes in MPLS, from Roopa Prabhu.

25) Fix POLLOUT notification for listening sockets in AF_UNIX, from Eric
    Dumazet.

26) Add new QED Qlogic river, from Yuval Mintz, Manish Chopra, and
    Sudarsana Kalluru.

27) Don't fetch timestamps on AF_UNIX sockets, from Hannes Frederic
    Sowa.

28) Support ipv6 geneve tunnels, from John W Linville.

29) Add flood control support to switchdev layer, from Ido Schimmel.

30) Fix CHECKSUM_PARTIAL handling of potentially fragmented frames, from
    Hannes Frederic Sowa.

31) Support persistent maps and progs in bpf, from Daniel Borkmann.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1790 commits)
  sh_eth: use DMA barriers
  switchdev: respect SKIP_EOPNOTSUPP flag in case there is no recursion
  net: sched: kill dead code in sch_choke.c
  irda: Delete an unnecessary check before the function call "irlmp_unregister_service"
  net: dsa: mv88e6xxx: include DSA ports in VLANs
  net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports
  net/core: fix for_each_netdev_feature
  vlan: Invoke driver vlan hooks only if device is present
  arcnet/com20020: add LEDS_CLASS dependency
  bpf, verifier: annotate verbose printer with __printf
  dp83640: Only wait for timestamps for packets with timestamping enabled.
  ptp: Change ptp_class to a proper bitmask
  dp83640: Prune rx timestamp list before reading from it
  dp83640: Delay scheduled work.
  dp83640: Include hash in timestamp/packet matching
  ipv6: fix tunnel error handling
  net/mlx5e: Fix LSO vlan insertion
  net/mlx5e: Re-eanble client vlan TX acceleration
  net/mlx5e: Return error in case mlx5e_set_features() fails
  net/mlx5e: Don't allow more than max supported channels
  ...

perf: pad raw data samples automatically

2015-10-22T13:42:13+00:00

Instead of WARN_ON in perf_event_output() on unpaded raw samples,
pad them automatically.

Signed-off-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

cgroup: keep zombies associated with their original cgroups

2015-10-15T20:41:53+00:00

cgroup_exit() is called when a task exits and disassociates the
exiting task from its cgroups and half-attach it to the root cgroup.
This is unnecessary and undesirable.

No controller actually needs an exiting task to be disassociated with
non-root cgroups.  Both cpu and perf_event controllers update the
association to the root cgroup from their exit callbacks just to keep
consistent with the cgroup core behavior.

Also, this disassociation makes it difficult to track resources held
by zombies or determine where the zombies came from.  Currently, pids
controller is completely broken as it uncharges on exit and zombies
always escape the resource restriction.  With cgroup association being
reset on exit, fixing it is pretty painful.

There's no reason to reset cgroup membership on exit.  The zombie can
be removed from its css_set so that it doesn't show up on
"cgroup.procs" and thus can't be migrated or interfere with cgroup
removal.  It can still pin and point to the css_set so that its cgroup
membership is maintained.  This patch makes cgroup core keep zombies
associated with their cgroups at the time of exit.

* Previous patches decoupled populated_cnt tracking from css_set
  lifetime, so a dying task can be simply unlinked from its css_set
  while pinning and pointing to the css_set.  This keeps css_set
  association from task side alive while hiding it from "cgroup.procs"
  and populated_cnt tracking.  The css_set reference is dropped when
  the task_struct is freed.

* ->exit() callback no longer needs the css arguments as the
  associated css never changes once PF_EXITING is set.  Removed.

* cpu and perf_events controllers no longer need ->exit() callbacks.
  There's no reason to explicitly switch away on exit.  The final
  schedule out is enough.  The callbacks are removed.

* On traditional hierarchies, nothing changes.  "/proc/PID/cgroup"
  still reports "/" for all zombies.  On the default hierarchy,
  "/proc/PID/cgroup" keeps reporting the cgroup that the task belonged
  to at the time of exit.  If the cgroup gets removed before the task
  is reaped, " (deleted)" is appended.

v2: Build brekage due to missing dummy cgroup_free() when
    !CONFIG_CGROUP fixed.

Signed-off-by: Tejun Heo 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Arnaldo Carvalho de Melo

perf/core, perf/x86: Change needlessly global functions and a variable to static

2015-09-28T06:09:52+00:00

Fixes various sparse warnings.

Signed-off-by: Geliang Tang 
Cc: Arnaldo Carvalho de Melo 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/70c14234da1bed6e3e67b9c419e2d5e376ab4f32.1443367286.git.geliangtang@163.com
Signed-off-by: Ingo Molnar

Merge branch 'perf/urgent' into perf/core, to pick up fixes before applying new changes

2015-09-18T07:24:01+00:00

Signed-off-by: Ingo Molnar

perf: Fix races in computing the header sizes

2015-09-18T07:20:26+00:00

There are two races with the current code:

 - Another event can join the group and compute a larger header_size
   concurrently, if the smaller store wins we'll have an incorrect
   header_size set.

 - We compute the header_size after the event becomes active,
   therefore its possible to use the size before its computed.

Remedy the first by moving the computation inside the ctx::mutex lock,
and the second by placing it _before_ perf_install_in_context().

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Arnaldo Carvalho de Melo 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar