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  1. 03 Nov, 2009 1 commit
  3. 12 Oct, 2009 1 commit
  5. 23 Sep, 2009 1 commit
  7. 21 Sep, 2009 1 commit
    • Ingo Molnar's avatar
      perf: Do the big rename: Performance Counters -> Performance Events · cdd6c482
      Ingo Molnar authored 
      Bye-bye Performance Counters, welcome Performance Events!

In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.

Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.

All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)

The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.

Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.

User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)

This patch has been generated via the following script:

  FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

  sed -i \
    -e 's/PERF_EVENT_/PERF_RECORD_/g' \
    -e 's/PERF_COUNTER/PERF_EVENT/g' \
    -e 's/perf_counter/perf_event/g' \
    -e 's/nb_counters/nb_events/g' \
    -e 's/swcounter/swevent/g' \
    -e 's/tpcounter_event/tp_event/g' \
    $FILES

  for N in $(find . -name perf_counter.[ch]); do
    M=$(echo $N | sed 's/perf_counter/perf_event/g')
    mv $N $M
  done

  FILES=$(find . -name perf_event.*)

  sed -i \
    -e 's/COUNTER_MASK/REG_MASK/g' \
    -e 's/COUNTER/EVENT/g' \
    -e 's/\<event\>/event_id/g' \
    -e 's/counter/event/g' \
    -e 's/Counter/Event/g' \
    $FILES

... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.

Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.

( NOTE: 'counters' are still the proper terminology when we deal
  with hardware registers - and these sed scripts are a bit
  over-eager in renaming them. I've undone some of that, but
  in case there's something left where 'counter' would be
  better than 'event' we can undo that on an individual basis
  instead of touching an otherwise nicely automated patch. )
Suggested-by: default avatarStephane Eranian <eranian@google.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarPaul Mackerras <paulus@samba.org>
Reviewed-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      cdd6c482
  9. 13 Sep, 2009 1 commit
  11. 18 Jun, 2009 1 commit
    • Steven Rostedt's avatar
      function-graph: add stack frame test · 71e308a2
      Steven Rostedt authored 
      In case gcc does something funny with the stack frames, or the return
from function code, we would like to detect that.

An arch may implement passing of a variable that is unique to the
function and can be saved on entering a function and can be tested
when exiting the function. Usually the frame pointer can be used for
this purpose.

This patch also implements this for x86. Where it passes in the stack
frame of the parent function, and will test that frame on exit.

There was a case in x86_32 with optimize for size (-Os) where, for a
few functions, gcc would align the stack frame and place a copy of the
return address into it. The function graph tracer modified the copy and
not the actual return address. On return from the funtion, it did not go
to the tracer hook, but returned to the parent. This broke the function
graph tracer, because the return of the parent (where gcc did not do
this funky manipulation) returned to the location that the child function
was suppose to. This caused strange kernel crashes.

This test detected the problem and pointed out where the issue was.

This modifies the parameters of one of the functions that the arch
specific code calls, so it includes changes to arch code to accommodate
the new prototype.

Note, I notice that the parsic arch implements its own push_return_trace.
This is now a generic function and the ftrace_push_return_trace should be
used instead. This patch does not touch that code.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      71e308a2
  13. 03 Jun, 2009 3 commits
    • Andi Kleen's avatar
      x86: fix panic with interrupts off (needed for MCE) · 4ef702c1
      Andi Kleen authored 
      For some time each panic() called with interrupts disabled
triggered the !irqs_disabled() WARN_ON in smp_call_function(),
producing ugly backtraces and confusing users.

This is a common situation with machine checks for example which
tend to call panic with interrupts disabled, but will also hit
in other situations e.g. panic during early boot.  In fact it
means that panic cannot be called in many circumstances, which
would be bad.

This all started with the new fancy queued smp_call_function,
which is then used by the shutdown path to shut down the other
CPUs.

On closer examination it turned out that the fancy RCU
smp_call_function() does lots of things not suitable in a panic
situation anyways, like allocating memory and relying on complex
system state.

I originally tried to patch this over by checking for panic
there, but it was quite complicated and the original patch
was also not very popular.  This also didn't fix some of the
underlying complexity problems.

The new code in post 2.6.29 tries to patch around this by
checking for oops_in_progress, but that is not enough to make
this fully safe and I don't think that's a real solution
because panic has to be reliable.

So instead use an own vector to reboot.  This makes the reboot
code extremly straight forward, which is definitely a big plus
in a panic situation where it is important to avoid relying on
too much kernel state.  The new simple code is also safe to be
called from interupts off region because it is very very simple.

There can be situations where it is important that panic
is reliable.  For example on a fatal machine check the panic
is needed to get the system up again and running as quickly
as possible.  So it's important that panic is reliable and
all function it calls simple.

This is why I came up with this simple vector scheme.
It's very hard to beat in simplicity.  Vectors are not
particularly precious anymore since all big systems are
using per CPU vectors.

Another possibility would have been to use an NMI similar
to kdump, but there is still the problem that NMIs don't
work reliably on some systems due to BIOS issues.  NMIs
would have been able to stop CPUs running with interrupts
off too.  In the sake of universal reliability I opted for
using a non NMI vector for now.

I put the reboot vector into the highest priority bucket of
the APIC vectors and moved the 64bit UV_BAU message down
instead into the next lower priority.

[ Impact: bug fix, fixes an old regression ]
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      4ef702c1
    • Andi Kleen's avatar
      x86, mce: implement bootstrapping for machine check wakeups · ccc3c319
      Andi Kleen authored 
      Machine checks support waking up the mcelog daemon quickly.

The original wake up code for this was pretty ugly, relying on
a idle notifier and a special process flag. The reason it did
it this way is that the machine check handler is not subject
to normal interrupt locking rules so it's not safe
to call wake_up().  Instead it set a process flag
and then either did the wakeup in the syscall return
or in the idle notifier.

This patch adds a new "bootstraping" method as replacement.

The idea is that the handler checks if it's in a state where
it is unsafe to call wake_up(). If it's safe it calls it directly.
When it's not safe -- that is it interrupted in a critical
section with interrupts disables -- it uses a new "self IPI" to trigger
an IPI to its own CPU. This can be done safely because IPI
triggers are atomic with some care. The IPI is raised
once the interrupts are reenabled and can then safely call
wake_up().

When APICs are disabled the event is just queued and will be picked up
eventually by the next polling timer. I think that's a reasonable
compromise, since it should only happen quite rarely.

Contains fixes from Ying Huang.

[ solve conflict on irqinit, make it work on 32bit (entry_arch.h) - HS ]
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      ccc3c319
    • Yong Wang's avatar
      perf_counter/x86: Remove the IRQ (non-NMI) handling bits · a3288106
      Yong Wang authored 
      Remove the IRQ (non-NMI) handling bits as NMI will be used always.
Signed-off-by: default avatarYong Wang <yong.y.wang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
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: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090603051255.GA2791@ywang-moblin2.bj.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      a3288106
  15. 28 May, 2009 2 commits
  17. 08 May, 2009 1 commit
  19. 18 Apr, 2009 1 commit
    • Steven Rostedt's avatar
      lockdep, x86: account for irqs enabled in paranoid_exit · 0300e7f1
      Steven Rostedt authored 
      I hit the check_flags error of lockdep:

 WARNING: at kernel/lockdep.c:2893 check_flags+0x1a7/0x1d0()
 [...]
 hardirqs last  enabled at (12567): [<ffffffff8026206a>] local_bh_enable+0xaa/0x110
 hardirqs last disabled at (12569): [<ffffffff80610c76>] int3+0x16/0x40
 softirqs last  enabled at (12566): [<ffffffff80514d2b>] lock_sock_nested+0xfb/0x110
 softirqs last disabled at (12568): [<ffffffff8058454e>] tcp_prequeue_process+0x2e/0xa0

The check_flags warning of lockdep tells me that lockdep thought interrupts
were disabled, but they were really enabled.

The numbers in the above parenthesis show the order of events:

 12566: softirqs last enabled:  lock_sock_nested
 12567: hardirqs last enabled:  local_bh_enable
 12568: softirqs last disabled: tcp_prequeue_process
 12566: hardirqs last disabled: int3

int3 is a breakpoint!

Examining this further, I have CONFIG_NET_TCPPROBE enabled which adds
break points into the kernel.

The paranoid_exit of the return of int3 does not account for enabling
interrupts on return to kernel. This code is a bit tricky since it
is also used by the nmi handler (when lockdep is off), and we must be
careful about the swapgs. We can not call kernel code after the swapgs
has been performed.

[ Impact: fix lockdep check_flags warning + self-turn-off ]
Acked-by: default avatarPeter Zijlsta <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      0300e7f1
  21. 10 Apr, 2009 1 commit
    • Steven Rostedt's avatar
      x86, function-graph: only save return values on x86_64 · e71e99c2
      Steven Rostedt authored 
      Impact: speed up

The return to handler portion of the function graph tracer should only
need to save the return values. The caller already saved off the
registers that the callee can modify. The returning function already
saved the registers it modified. When we call our own trace function
it too will save the registers that the callee must restore.

There's no reason to save off anything more that the registers used
to return the values.

Note, I did a complete kernel build with this modification and the
function graph tracer running on x86_64.
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      e71e99c2
  23. 07 Apr, 2009 1 commit
  25. 12 Mar, 2009 2 commits
  27. 04 Mar, 2009 1 commit
  29. 24 Feb, 2009 2 commits
  31. 13 Feb, 2009 1 commit
  33. 03 Feb, 2009 1 commit
  35. 30 Jan, 2009 1 commit
  37. 21 Jan, 2009 1 commit
  39. 18 Jan, 2009 4 commits
  41. 16 Jan, 2009 1 commit
    • Tejun Heo's avatar
      x86: merge 64 and 32 SMP percpu handling · 9939ddaf
      Tejun Heo authored 
      Now that pda is allocated as part of percpu, percpu doesn't need to be
accessed through pda.  Unify x86_64 SMP percpu access with x86_32 SMP
one.  Other than the segment register, operand size and the base of
percpu symbols, they behave identical now.

This patch replaces now unnecessary pda->data_offset with a dummy
field which is necessary to keep stack_canary at its place.  This
patch also moves per_cpu_offset initialization out of init_gdt() into
setup_per_cpu_areas().  Note that this change also necessitates
explicit per_cpu_offset initializations in voyager_smp.c.

With this change, x86_OP_percpu()'s are as efficient on x86_64 as on
x86_32 and also x86_64 can use assembly PER_CPU macros.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      9939ddaf
  43. 11 Jan, 2009 1 commit
  45. 16 Dec, 2008 1 commit
  47. 08 Dec, 2008 1 commit
    • Ingo Molnar's avatar
      performance counters: x86 support · 241771ef
      Ingo Molnar authored 
      Implement performance counters for x86 Intel CPUs.

It's simplified right now: the PERFMON CPU feature is assumed,
which is available in Core2 and later Intel CPUs.

The design is flexible to be extended to more CPU types as well.
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      241771ef
  49. 03 Dec, 2008 2 commits
  51. 02 Dec, 2008 1 commit
    • Frederic Weisbecker's avatar
      tracing/function-graph-tracer: support for x86-64 · 48d68b20
      Frederic Weisbecker authored 
      Impact: extend and enable the function graph tracer to 64-bit x86

This patch implements the support for function graph tracer under x86-64.
Both static and dynamic tracing are supported.

This causes some small CPP conditional asm on arch/x86/kernel/ftrace.c I
wanted to use probe_kernel_read/write to make the return address
saving/patching code more generic but it causes tracing recursion.

That would be perhaps useful to implement a notrace version of these
function for other archs ports.

Note that arch/x86/process_64.c is not traced, as in X86-32. I first
thought __switch_to() was responsible of crashes during tracing because I
believed current task were changed inside but that's actually not the
case (actually yes, but not the "current" pointer).

So I will have to investigate to find the functions that harm here, to
enable tracing of the other functions inside (but there is no issue at
this time, while process_64.c stays out of -pg flags).

A little possible race condition is fixed inside this patch too. When the
tracer allocate a return stack dynamically, the current depth is not
initialized before but after. An interrupt could occur at this time and,
after seeing that the return stack is allocated, the tracer could try to
trace it with a random uninitialized depth. It's a prevention, even if I
hadn't problems with it.
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      48d68b20
  53. 28 Nov, 2008 3 commits
  55. 27 Nov, 2008 2 commits
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