Commit Graph

145434 Commits

Author SHA1 Message Date
Peter Zijlstra
a78ac32587 perf_counter: Generic per counter interrupt throttle
Introduce a generic per counter interrupt throttle.

This uses the perf_counter_overflow() quick disable to throttle a specific
counter when its going too fast when a pmu->unthrottle() method is provided
which can undo the quick disable.

Power needs to implement both the quick disable and the unthrottle method.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525153931.703093461@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 21:41:12 +02:00
Peter Zijlstra
48e22d56ec perf_counter: x86: Remove interrupt throttle
remove the x86 specific interrupt throttle

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525153931.616671838@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 21:41:12 +02:00
Peter Zijlstra
ff99be573e perf_counter: x86: Expose INV and EDGE bits
Expose the INV and EDGE bits of the PMU to raw configs.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525153931.494709027@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 21:41:11 +02:00
Peter Zijlstra
10989fb245 perf_counter: Fix PERF_COUNTER_CONTEXT_SWITCHES for cpu counters
Ingo noticed that cpu counters had 0 context switches, even though
there was plenty scheduling on the cpu.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525124600.419025548@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 14:55:01 +02:00
Peter Zijlstra
6ab423e0ea perf_counter: Propagate inheritance failures down the fork() path
Fail fork() when we fail inheritance for some reason (-ENOMEM most likely).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525124600.324656474@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 14:55:01 +02:00
Peter Zijlstra
771d7cde14 perf_counter: Make pctrl() affect inherited counters too
Paul noted that the new ptcrl() didn't work on child counters.

Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525124600.203151469@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 14:55:00 +02:00
Peter Zijlstra
e527ea312f perf_counter: Remove unused ABI bits
extra_config_len isn't used for anything, remove it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525124600.116035832@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 14:55:00 +02:00
Peter Zijlstra
266dfb0b58 perf_counter: Fix perf-$cmd invokation
Fix:

  $ perf-top
  fatal: cannot handle -top internally

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525124559.995591577@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 14:54:59 +02:00
Ingo Molnar
d3f4b3855b perf stat: flip around ':k' and ':u' flags
This output:

 $ perf stat -e 0:1:k -e 0:1:u ./hello
  Performance counter stats for './hello':
          140131  instructions         (events)
         1906968  instructions         (events)

Is quite confusing - as :k means "user instructions", :u means
"kernel instructions".

Flip them around - as the 'exclude' property is not intuitive in
the flag naming.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 14:40:01 +02:00
Ingo Molnar
e4cbb4e3ac perf_counter: Move child perfcounter init to after scheduler init
Initialize a task's perfcounters (inherit from parent, etc.) after
the child task's scheduler fields have been initialized already.

[ Impact: cleanup ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 13:05:06 +02:00
Mike Galbraith
d94b943054 perf top: Reduce display overhead
Iterate over the symbol table once per display interval, and
copy/sort/tally/decay only those symbols which are active.

Before:

 top - 10:14:53 up  4:08, 17 users,  load average: 1.17, 1.53, 1.49
 Tasks: 273 total,   5 running, 268 sleeping,   0 stopped,   0 zombie
 Cpu(s):  6.9%us, 38.2%sy,  0.0%ni, 19.9%id,  0.0%wa,  0.0%hi, 35.0%si,  0.0%st

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  P COMMAND
 28504 root      20   0  1044  260  164 S   58  0.0   0:04.19 2 netserver
 28499 root      20   0  1040  412  316 R   51  0.0   0:04.15 0 netperf
 28500 root      20   0  1040  408  316 R   50  0.0   0:04.14 1 netperf
 28503 root      20   0  1044  260  164 S   50  0.0   0:04.01 1 netserver
 28501 root      20   0  1044  260  164 S   49  0.0   0:03.99 0 netserver
 28502 root      20   0  1040  412  316 S   43  0.0   0:03.96 2 netperf
 28468 root      20   0 1892m 325m  972 S   16 10.8   0:10.50 3 perf
 28467 root      20   0 1892m 325m  972 R    2 10.8   0:00.72 3 perf

After:

 top - 10:16:30 up  4:10, 17 users,  load average: 2.27, 1.88, 1.62
 Tasks: 273 total,   6 running, 267 sleeping,   0 stopped,   0 zombie
 Cpu(s):  2.5%us, 39.7%sy,  0.0%ni, 24.6%id,  0.0%wa,  0.0%hi, 33.3%si,  0.0%st

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  P COMMAND
 28590 root      20   0  1040  412  316 S   54  0.0   0:07.85 2 netperf
 28589 root      20   0  1044  260  164 R   54  0.0   0:07.84 0 netserver
 28588 root      20   0  1040  412  316 R   50  0.0   0:07.89 1 netperf
 28591 root      20   0  1044  256  164 S   50  0.0   0:07.82 1 netserver
 28587 root      20   0  1040  408  316 R   47  0.0   0:07.61 0 netperf
 28592 root      20   0  1044  260  164 R   47  0.0   0:07.85 2 netserver
 28378 root      20   0  8732 1300  860 R    2  0.0   0:01.81 3 top
 28577 root      20   0 1892m 165m  972 R    2  5.5   0:00.48 3 perf
 28578 root      20   0 1892m 165m  972 S    2  5.5   0:00.04 3 perf

[ Impact: optimization ]

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 13:01:17 +02:00
Ingo Molnar
85a9f92002 perf_counter tools: increase limits, fix
NR_CPUS and NR_COUNTERS goes up quadratic ... 1024x4096 was far
too ambitious upper limit - go for 256x256 which is still plenty.

[ Impact: reduce perf tool memory consumption ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-25 09:59:50 +02:00
Ingo Molnar
a3862d3f81 perf_counter: Increase mmap limit
In a default 'perf top' run the tool will create a counter for
each online CPU. With enough CPUs this will eventually exhaust
the default limit.

So scale it up with the number of online CPUs.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-24 09:02:37 +02:00
Mike Galbraith
c2990a2a58 perf top: fix segfault
c6eb13 increased stack usage such that perf-top now croaks on startup.

Take event_array and mmap_array off the stack to prevent segfault on boxen
with smallish ulimit -s setting.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-24 08:57:08 +02:00
Peter Zijlstra
475c557973 perf_counter: Remove perf_counter_context::nr_enabled
now that pctrl() no longer disables other people's counters,
remove the PMU cache code that deals with that.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163013.032998331@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-24 08:24:30 +02:00
Peter Zijlstra
082ff5a276 perf_counter: Change pctrl() behaviour
Instead of en/dis-abling all counters acting on a particular
task, en/dis- able all counters we created.

[ v2: fix crash on first counter enable ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.916937244@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-24 08:24:08 +02:00
Peter Zijlstra
aa9c67f53d perf_counter: Simplify context cleanup
Use perf_counter_remove_from_context() to remove counters from
the context.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.796275849@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-23 19:37:47 +02:00
Peter Zijlstra
1a482f38c5 perf_counter: Fix userspace build
recent userspace (F11) seems to already include the
linux/unistd.h bits which means we cannot include the version
in the kernel sources due to the header guards being the same.

Ensure we include the kernel version first.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.739756497@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-23 19:37:46 +02:00
Peter Zijlstra
682076ae1d perf_counter: Sanitize context locking
Ensure we're consistent with the context locks.

 context->mutex
   context->lock
     list_{add,del}_counter();

so that either lock is sufficient to stabilize the context.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.618790733@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-23 19:37:46 +02:00
Peter Zijlstra
fccc714b31 perf_counter: Sanitize counter->mutex
s/counter->mutex/counter->child_mutex/ and make sure its only
used to protect child_list.

The usage in __perf_counter_exit_task() doesn't appear to be
problematic since ctx->mutex also covers anything related to fd
tear-down.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.533186528@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-23 19:37:45 +02:00
Peter Zijlstra
e220d2dcb9 perf_counter: Fix dynamic irq_period logging
We call perf_adjust_freq() from perf_counter_task_tick() which
is is called under the rq->lock causing lock recursion.
However, it's no longer required to be called under the
rq->lock, so remove it from under it.

Also, fix up some related comments.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.476197912@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-23 19:37:44 +02:00
Ingo Molnar
c6eb13847b perf_counter tools: increase limits
I tried to run with 300 active counters and the tools bailed out
because our limit was at 64. So increase the counter limit to 1024
and the CPU limit to 4096.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-22 18:18:28 +02:00
Ingo Molnar
910431c7f2 perf_counter: fix !PERF_COUNTERS build failure
Update the !CONFIG_PERF_COUNTERS prototype too, for
perf_counter_task_sched_out().

[ Impact: build fix ]

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <18966.10666.517218.332164@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-22 12:33:14 +02:00
Paul Mackerras
564c2b210a perf_counter: Optimize context switch between identical inherited contexts
When monitoring a process and its descendants with a set of inherited
counters, we can often get the situation in a context switch where
both the old (outgoing) and new (incoming) process have the same set
of counters, and their values are ultimately going to be added together.
In that situation it doesn't matter which set of counters are used to
count the activity for the new process, so there is really no need to
go through the process of reading the hardware counters and updating
the old task's counters and then setting up the PMU for the new task.

This optimizes the context switch in this situation.  Instead of
scheduling out the perf_counter_context for the old task and
scheduling in the new context, we simply transfer the old context
to the new task and keep using it without interruption.  The new
context gets transferred to the old task.  This means that both
tasks still have a valid perf_counter_context, so no special case
is introduced when the old task gets scheduled in again, either on
this CPU or another CPU.

The equivalence of contexts is detected by keeping a pointer in
each cloned context pointing to the context it was cloned from.
To cope with the situation where a context is changed by adding
or removing counters after it has been cloned, we also keep a
generation number on each context which is incremented every time
a context is changed.  When a context is cloned we take a copy
of the parent's generation number, and two cloned contexts are
equivalent only if they have the same parent and the same
generation number.  In order that the parent context pointer
remains valid (and is not reused), we increment the parent
context's reference count for each context cloned from it.

Since we don't have individual fds for the counters in a cloned
context, the only thing that can make two clones of a given parent
different after they have been cloned is enabling or disabling all
counters with prctl.  To account for this, we keep a count of the
number of enabled counters in each context.  Two contexts must have
the same number of enabled counters to be considered equivalent.

Here are some measurements of the context switch time as measured with
the lat_ctx benchmark from lmbench, comparing the times obtained with
and without this patch series:

		-----Unmodified-----		With this patch series
Counters:	none	2 HW	4H+4S	none	2 HW	4H+4S

2 processes:
Average		3.44	6.45	11.24	3.12	3.39	3.60
St dev		0.04	0.04	0.13	0.05	0.17	0.19

8 processes:
Average		6.45	8.79	14.00	5.57	6.23	7.57
St dev		1.27	1.04	0.88	1.42	1.46	1.42

32 processes:
Average		5.56	8.43	13.78	5.28	5.55	7.15
St dev		0.41	0.47	0.53	0.54	0.57	0.81

The numbers are the mean and standard deviation of 20 runs of
lat_ctx.  The "none" columns are lat_ctx run directly without any
counters.  The "2 HW" columns are with lat_ctx run under perfstat,
counting cycles and instructions.  The "4H+4S" columns are lat_ctx run
under perfstat with 4 hardware counters and 4 software counters
(cycles, instructions, cache references, cache misses, task
clock, context switch, cpu migrations, and page faults).

[ Impact: performance optimization of counter context-switches ]

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <18966.10666.517218.332164@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-22 12:18:20 +02:00
Paul Mackerras
a63eaf34ae perf_counter: Dynamically allocate tasks' perf_counter_context struct
This replaces the struct perf_counter_context in the task_struct with
a pointer to a dynamically allocated perf_counter_context struct.  The
main reason for doing is this is to allow us to transfer a
perf_counter_context from one task to another when we do lazy PMU
switching in a later patch.

This has a few side-benefits: the task_struct becomes a little smaller,
we save some memory because only tasks that have perf_counters attached
get a perf_counter_context allocated for them, and we can remove the
inclusion of <linux/perf_counter.h> in sched.h, meaning that we don't
end up recompiling nearly everything whenever perf_counter.h changes.

The perf_counter_context structures are reference-counted and freed
when the last reference is dropped.  A context can have references
from its task and the counters on its task.  Counters can outlive the
task so it is possible that a context will be freed well after its
task has exited.

Contexts are allocated on fork if the parent had a context, or
otherwise the first time that a per-task counter is created on a task.
In the latter case, we set the context pointer in the task struct
locklessly using an atomic compare-and-exchange operation in case we
raced with some other task in creating a context for the subject task.

This also removes the task pointer from the perf_counter struct.  The
task pointer was not used anywhere and would make it harder to move a
context from one task to another.  Anything that needed to know which
task a counter was attached to was already using counter->ctx->task.

The __perf_counter_init_context function moves up in perf_counter.c
so that it can be called from find_get_context, and now initializes
the refcount, but is otherwise unchanged.

We were potentially calling list_del_counter twice: once from
__perf_counter_exit_task when the task exits and once from
__perf_counter_remove_from_context when the counter's fd gets closed.
This adds a check in list_del_counter so it doesn't do anything if
the counter has already been removed from the lists.

Since perf_counter_task_sched_in doesn't do anything if the task doesn't
have a context, and leaves cpuctx->task_ctx = NULL, this adds code to
__perf_install_in_context to set cpuctx->task_ctx if necessary, i.e. in
the case where the current task adds the first counter to itself and
thus creates a context for itself.

This also adds similar code to __perf_counter_enable to handle a
similar situation which can arise when the counters have been disabled
using prctl; that also leaves cpuctx->task_ctx = NULL.

[ Impact: refactor counter context management to prepare for new feature ]

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <18966.10075.781053.231153@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-22 12:18:19 +02:00
Ingo Molnar
34adc80622 perf_counter: Fix context removal deadlock
Disable the PMU globally before removing a counter from a
context. This fixes the following lockup:

[22081.741922] ------------[ cut here ]------------
[22081.746668] WARNING: at arch/x86/kernel/cpu/perf_counter.c:803 intel_pmu_handle_irq+0x9b/0x24e()
[22081.755624] Hardware name: X8DTN
[22081.758903] perfcounters: irq loop stuck!
[22081.762985] Modules linked in:
[22081.766136] Pid: 11082, comm: perf Not tainted 2.6.30-rc6-tip #226
[22081.772432] Call Trace:
[22081.774940]  <NMI>  [<ffffffff81019aed>] ? intel_pmu_handle_irq+0x9b/0x24e
[22081.781993]  [<ffffffff81019aed>] ? intel_pmu_handle_irq+0x9b/0x24e
[22081.788368]  [<ffffffff8104505c>] ? warn_slowpath_common+0x77/0xa3
[22081.794649]  [<ffffffff810450d3>] ? warn_slowpath_fmt+0x40/0x45
[22081.800696]  [<ffffffff81019aed>] ? intel_pmu_handle_irq+0x9b/0x24e
[22081.807080]  [<ffffffff814d1a72>] ? perf_counter_nmi_handler+0x3f/0x4a
[22081.813751]  [<ffffffff814d2d09>] ? notifier_call_chain+0x58/0x86
[22081.819951]  [<ffffffff8105b250>] ? notify_die+0x2d/0x32
[22081.825392]  [<ffffffff814d1414>] ? do_nmi+0x8e/0x242
[22081.830538]  [<ffffffff814d0f0a>] ? nmi+0x1a/0x20
[22081.835342]  [<ffffffff8117e102>] ? selinux_file_free_security+0x0/0x1a
[22081.842105]  [<ffffffff81018793>] ? x86_pmu_disable_counter+0x15/0x41
[22081.848673]  <<EOE>>  [<ffffffff81018f3d>] ? x86_pmu_disable+0x86/0x103
[22081.855512]  [<ffffffff8108fedd>] ? __perf_counter_remove_from_context+0x0/0xfe
[22081.862926]  [<ffffffff8108fcbc>] ? counter_sched_out+0x30/0xce
[22081.868909]  [<ffffffff8108ff36>] ? __perf_counter_remove_from_context+0x59/0xfe
[22081.876382]  [<ffffffff8106808a>] ? smp_call_function_single+0x6c/0xe6
[22081.882955]  [<ffffffff81091b96>] ? perf_release+0x86/0x14c
[22081.888600]  [<ffffffff810c4c84>] ? __fput+0xe7/0x195
[22081.893718]  [<ffffffff810c213e>] ? filp_close+0x5b/0x62
[22081.899107]  [<ffffffff81046a70>] ? put_files_struct+0x64/0xc2
[22081.905031]  [<ffffffff8104841a>] ? do_exit+0x1e2/0x6ef
[22081.910360]  [<ffffffff814d0a60>] ? _spin_lock_irqsave+0x9/0xe
[22081.916292]  [<ffffffff8104898e>] ? do_group_exit+0x67/0x93
[22081.921953]  [<ffffffff810489cc>] ? sys_exit_group+0x12/0x16
[22081.927759]  [<ffffffff8100baab>] ? system_call_fastpath+0x16/0x1b
[22081.934076] ---[ end trace 3a3936ce3e1b4505 ]---

And could potentially also fix the lockup reported by Marcelo Tosatti.

Also, print more debug info in case of a detected lockup.

[ Impact: fix lockup ]

Reported-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-20 20:12:54 +02:00
Peter Zijlstra
afedadf23a perf_counter: Optimize sched in/out of counters
Avoid a function call for !group counters by directly calling the counter
function.

[ Impact: micro-optimize the code ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090520102553.511933670@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-20 12:43:34 +02:00
Peter Zijlstra
b986d7ec0f perf_counter: Optimize disable of time based sw counters
Currently we call hrtimer_cancel() unconditionally on disable of time based
software counters. Avoid when possible.

[ Impact: micro-optimize the code ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090520102553.388185031@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-20 12:43:33 +02:00
Peter Zijlstra
26b119bc81 perf_counter: Log irq_period changes
For the dynamic irq_period code, log whenever we change the period so that
analyzing code can normalize the event flow.

[ Impact: add new feature to allow more precise profiling ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090520102553.298769743@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-20 12:43:33 +02:00
Peter Zijlstra
d7b629a34f perf_counter: Solve the rotate_ctx vs inherit race differently
Instead of disabling RR scheduling of the counters, use a different list
that does not get rotated to iterate the counters on inheritance.

[ Impact: cleanup, optimization ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090520102553.237504544@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-20 12:43:32 +02:00
Ingo Molnar
c44d70a340 perf_counter: fix counter inheritance race
Context rotation should not occur when we are in the middle of
walking the counter list when inheriting counters ...

[ Impact: fix occasionally incorrect perf stat results ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-20 00:22:30 +02:00
Ingo Molnar
33b2fb303f perf_counter: fix counter freeing logic
Fix counter lifetime bugs which explain the crashes reported by
Marcelo Tosatti and Arnaldo Carvalho de Melo.

The new rule is: flushing + freeing is only done for a task's
own counters, never for other tasks.

[ Impact: fix crashes/lockups with inherited counters ]

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reported-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-20 00:22:24 +02:00
Ingo Molnar
b68f1d2e7a perf_counter, x86: speed up the scheduling fast-path
We have to set up the LVT entry only at counter init time, not at
every switch-in time.

There's friction between NMI and non-NMI use here - we'll probably
remove the per counter configurability of it - but until then, dont
slow down things ...

[ Impact: micro-optimization ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-18 09:37:09 +02:00
Paul Mackerras
c0daaf3f1f perf_counter: powerpc: initialize cpuhw pointer before use
Commit 9e35ad38 ("perf_counter: Rework the perf counter
disable/enable") added code to the powerpc hw_perf_enable (renamed
from hw_perf_restore) to test cpuhw->disabled and return immediately
if it is not set (i.e. if the PMU is already enabled).

Unfortunately the test got added before cpuhw was initialized,
resulting in an oops the first time hw_perf_enable got called.
This fixes it by moving the initialization of cpuhw to before
cpuhw->disabled is tested.

[ Impact: fix oops-causing bug on powerpc ]

Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <18960.56772.869734.304631@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-18 07:38:42 +02:00
Ingo Molnar
dc3f81b129 Merge commit 'v2.6.30-rc6' into perfcounters/core
Merge reason: this branch was on an -rc4 base, merge it up to -rc6
              to get the latest upstream fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-18 07:37:49 +02:00
Ingo Molnar
d2517a49d5 perf_counter, x86: fix zero irq_period counters
The quirk to irq_period unearthed an unrobustness we had in the
hw_counter initialization sequence: we left irq_period at 0, which
was then quirked up to 2 ... which then generated a _lot_ of
interrupts during 'perf stat' runs, slowed them down and skewed
the counter results in general.

Initialize irq_period to the maximum instead.

[ Impact: fix perf stat results ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-17 12:27:37 +02:00
Ingo Molnar
0203026b58 perf_counter: fix threaded task exit
Flushing counters in __exit_signal() with irqs disabled is not
a good idea as perf_counter_exit_task() acquires mutexes. So
flush it before acquiring the tasklist lock.

(Note, we still need a fix for when the PID has been unhashed.)

[ Impact: fix crash with inherited counters ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-17 11:26:57 +02:00
Peter Zijlstra
856d56b9e5 perf_counter: Fix counter inheritance
Srivatsa Vaddagiri reported that a Java workload triggers this
warning in kernel/exit.c:

   WARN_ON_ONCE(!list_empty(&tsk->perf_counter_ctx.counter_list));

Add the inherited counter propagation on self-detach, this could
cause counter leaks and incomplete stats in threaded code like
the below:

  #include <pthread.h>
  #include <unistd.h>

  void *thread(void *arg)
  {
          sleep(5);
          return NULL;
  }

  void main(void)
  {
          pthread_t thr;
          pthread_create(&thr, NULL, thread, NULL);
  }

Reported-by: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-17 07:52:24 +02:00
Peter Zijlstra
8bc2095951 perf_counter: Fix inheritance cleanup code
Clean up code that open-coded the list_{add,del}_counter() code in
__perf_counter_exit_task() which consequently diverged. This could
lead to software counter crashes.

Also, fold the ctx->nr_counter inc/dec into those functions and clean
up some of the related code.

[ Impact: fix potential sw counter crash, cleanup ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-17 07:52:23 +02:00
Linus Torvalds
1406de8e11 Linux 2.6.30-rc6 2009-05-15 21:12:57 -07:00
Linus Torvalds
72357d5955 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI MSI: Fix MSI-X with NIU cards
  PCI: Fix pci-e port driver slot_reset bad default return value
2009-05-15 16:47:55 -07:00
Linus Torvalds
7c7327d966 Merge git://git.kernel.org/pub/scm/linux/kernel/git/holtmann/bluetooth-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/holtmann/bluetooth-2.6:
  Bluetooth: Don't trigger disconnect timeout for security mode 3 pairing
  Bluetooth: Don't use hci_acl_connect_cancel() for incoming connections
  Bluetooth: Fix wrong module refcount when connection setup fails

Another case of me handling the fallout from Davem's unfortunate
addiction to shuffleboard.

Won't anybody think of the children? Join the anti-shuffleboard league
today!
2009-05-15 14:30:02 -07:00
Linus Torvalds
40f293ff83 Merge branch 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel
* 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel:
  drm/i915: Add new GET_PIPE_FROM_CRTC_ID ioctl.
  drm/i915: Set HDMI hot plug interrupt enable for only the output in question.
  drm/i915: Include 965GME pci ID in IS_I965GM(dev) to match UMS.
  drm/i915: Use the GM45 VGA hotplug workaround on G45 as well.
  drm/i915: ignore LVDS on intel graphics systems that lie about having it
  drm/i915: sanity check IER at wait_request time
  drm/i915: workaround IGD i2c bus issue in kernel side (v2)
  drm/i915: Don't allow binding objects into the last page of the aperture.
  drm/i915: save/restore fence registers across suspend/resume
  drm/i915: x86 always has writeq. Add I915_READ64 for symmetry.
2009-05-15 13:22:11 -07:00
Linus Torvalds
8c21f34126 Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of ssh://master.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  libata: Media rotation rate and form factor heuristics
  libata: Report disk alignment and physical block size
  sata_fsl: Fix the command description of FSL SATA controller
  sata_fsl: Fix compile warnings
  [libata] sata_sx4: fixup interrupt handling
  [libata] sata_sx4: convert to new exception handling methods
2009-05-15 12:04:49 -07:00
Linus Torvalds
3346857f6f Merge git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6:
  iwlwifi: fix device id registration for 6000 series 2x2 devices
  ath5k: update channel in sw state after stopping RX and TX
  rtl8187: use DMA-aware buffers with usb_control_msg
  mac80211: avoid NULL ptr deref when finding max_rates in PID and minstrel
  airo: airo_get_encode{,ext} potential buffer overflow

Pulled directly by Linus because Davem is off playing shuffle-board at
some Alaskan cruise, and the NULL ptr deref issue hits people and should
get merged sooner rather than later.

David - make us proud on the shuffle-board tournament!
2009-05-15 12:02:06 -07:00
Martin K. Petersen
4bca328643 libata: Media rotation rate and form factor heuristics
This patch provides new heuristics for parsing both the form factor and
media rotation rate ATA IDENFITY words.

The reported ATA version must be 7 or greater and the device must return
values defined as valid in the standard.  Only then are the
characteristics reported to SCSI via the VPD B1 page.

This seems like a reasonable compromise to me considering that we have
been shipping several kernel releases that key off the rotation rate bit
without any version checking whatsoever.  With no complaints so far.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-05-15 14:14:56 -04:00
Martin K. Petersen
61d79a8eb3 libata: Report disk alignment and physical block size
For disks with 4KB sectors, report the correct block size and alignment
when filling out the READ CAPACITY(16) response.

This patch is based upon code from Matthew Wilcox' 4KB ATA tree.  I
fixed the bug I reported a while back caused by ATA and SCSI using
different approaches to describing the alignment.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-05-15 14:14:22 -04:00
Dave Liu
d358724385 sata_fsl: Fix the command description of FSL SATA controller
The bit 11 of command description is reserved bit in Freescale
SATA controller and needs to be set to '1'.  This is needed to
make sure the last write from the controller to the buffer
descriptor is seen before an interrupt is raised.

Signed-off-by: Dave Liu <daveliu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-05-15 14:14:08 -04:00
Kumar Gala
f48c019f15 sata_fsl: Fix compile warnings
We we build with dma_addr_t as a 64-bit quantity we get:

drivers/ata/sata_fsl.c: In function 'sata_fsl_fill_sg':
drivers/ata/sata_fsl.c:340: warning: format '%x' expects type 'unsigned int', but argument 4 has type 'dma_addr_t'

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-05-15 14:14:01 -04:00
David Milburn
19799bfc5d [libata] sata_sx4: fixup interrupt handling
Issuing ATA_CMD_SET_FEATURES (0xef) times out because
pdc20621_interrupt ignores command completion since
ATA_TFLAG_POLLING flag is set.

This has already been fixed for sata_promise:

commit 51b94d2a5a
Author: Tejun Heo <htejun@gmail.com>
Date:   Fri Jun 8 13:46:55 2007 -0700

    sata_promise: use TF interface for polling NODATA commands

Also, this patch includes Mikael's original patches:

http://marc.info/?l=linux-ide&m=121135828227724&w=2
http://marc.info/?l=linux-ide&m=121144512109826&w=2

Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-05-15 14:08:10 -04:00