Provide the ability to configure a counter to send its output
to another (already existing) counter's output stream.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: stephane eranian <eranian@googlemail.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090819092023.980284148@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Currently, if a group is created where the group leader is
initially disabled but a non-leader member is initially
enabled, and then the leader is subsequently enabled some time
later, the time_enabled for the non-leader member will reflect
the whole time since it was created, not just the time since
the leader was enabled.

This is incorrect, because all of the members are effectively
disabled while the leader is disabled, since none of the
members can go on the PMU if the leader can't.

Thus we have to update the ->tstamp_enabled for all the enabled
group members when a group leader is enabled, so that the
time_enabled computation only counts the time since the leader
was enabled.

Similarly, when disabling a group leader we have to update the
time_enabled and time_running for all of the group members.

Also, in update_counter_times, we have to treat a counter whose
group leader is disabled as being disabled.
Reported-by: NStephane Eranian <eranian@googlemail.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
LKML-Reference: <19091.29664.342227.445006@drongo.ozlabs.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:
	tools/perf/builtin-annotate.c
	tools/perf/builtin-report.c

Merge reason: resolve these conflicts.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When you iterate a list, using the iterator is useful.

Before:

   ID: 5
   ID: 5
   ID: 5
   ID: 5
   EVNT: 0x40088b scale: nan ID: 5 CNT: 1006252 ID: 6 CNT: 1011090 ID: 7 CNT: 1011196 ID: 8 CNT: 1011095
   EVNT: 0x40088c scale: 1.000000 ID: 5 CNT: 2003065 ID: 6 CNT: 2011671 ID: 7 CNT: 2012620 ID: 8 CNT: 2013479
   EVNT: 0x40088c scale: 1.000000 ID: 5 CNT: 3002390 ID: 6 CNT: 3015996 ID: 7 CNT: 3018019 ID: 8 CNT: 3020006
   EVNT: 0x40088b scale: 1.000000 ID: 5 CNT: 4002406 ID: 6 CNT: 4021120 ID: 7 CNT: 4024241 ID: 8 CNT: 4027059

After:

   ID: 1
   ID: 2
   ID: 3
   ID: 4
   EVNT: 0x400889 scale: nan ID: 1 CNT: 1005270 ID: 2 CNT: 1009833 ID: 3 CNT: 1010065 ID: 4 CNT: 1010088
   EVNT: 0x400898 scale: nan ID: 1 CNT: 2001531 ID: 2 CNT: 2022309 ID: 3 CNT: 2022470 ID: 4 CNT: 2022627
   EVNT: 0x400888 scale: 0.489467 ID: 1 CNT: 3001261 ID: 2 CNT: 3027088 ID: 3 CNT: 3027941 ID: 4 CNT: 3028762
Reported-by: Nstephane eranian <eranian@googlemail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey J Ashford <cjashfor@us.ibm.com>
Cc: perfmon2-devel <perfmon2-devel@lists.sourceforge.net>
LKML-Reference: <1250867976.7538.73.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add an owner check to opening perf.data files and a switch to
silence it.

Because perf-report/perf-annotate are binary parsers reading
another users' perf.data file could be a security risk if the
file were explicitly engineered to trigger bugs in the parser
(we hope of course there are non such bugs, but you never
know).
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090819092023.896648538@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

pushd tools/perf/Documentation
make html
popd

is failing for me...

    ASCIIDOC perf-annotate.html
ERROR: unsafe: include file: /etc/asciidoc/./stylesheets/xhtml11.css
ERROR: unsafe: include file:
/etc/asciidoc/./stylesheets/xhtml11-manpage.css
ERROR: unsafe: include file:
/etc/asciidoc/./stylesheets/xhtml11-quirks.css
make: *** [perf-annotate.html] Error 1

Apparently asciidoc "unsafe" is the default mode of operation
in practice.

https://bugzilla.redhat.com/show_bug.cgi?id=506953

Works tidily now.
Signed-off-by: NKyle McMartin <kyle@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090818164125.GM25206@bombadil.infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The librarization of the thread helpers between annotate and
report lost some perf report specifics.

thread__insert_map() had its most uptodate version in perf
report which cared about partial map overlapping. In case of
overlap between two maps, perf annotate's version removes the
whole old map without considering if it partially or
absolutely overlaps the new map.

We exported the odd version, change it by using the perf
report version.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250607843-7395-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The librarization of the thread helpers between annotate and
report lost some perf report specifics.

This patch fixes the thread comm column adjusting that has
been omitted during this export.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250604226-6852-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Linus reported this perf annotate segfault:

        [torvalds@nehalem git]$ perf annotate unmap_vmas
        Segmentation fault

       	#0  map__clone (self=<value optimized out>) at builtin-annotate.c:236
       	#1  thread__fork (self=<value optimized out>) at builtin-annotate.c:372

The bug here was that builtin-annotate.c was a copy of
builtin-report.c and a threading related fix to builtin-report.c
didnt get propagated to builtin-annotate.c ...
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

PARISC does not build:

/home/mingo/tip/kernel/perf_counter.c: In function 'perf_counter_index':
/home/mingo/tip/kernel/perf_counter.c:2016: error: 'PERF_COUNTER_INDEX_OFFSET' undeclared (first use in this function)
/home/mingo/tip/kernel/perf_counter.c:2016: error: (Each undeclared identifier is reported only once
/home/mingo/tip/kernel/perf_counter.c:2016: error: for each function it appears in.)

As PERF_COUNTER_INDEX_OFFSET is not defined.

Now, we could define it in the architecture - but lets also provide
a core default of 0 (which happens to be what all but one
architecture uses at the moment).

Architectures that need a different index offset should set this
value in their asm/perf_counter.h files.

Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The _XOPEN_SOURCE* defines are not really needed on Linux and
it's not like we'll port this to AIX ;-)

The define also broke the build with gcc 4.4.1:

 CC util/trace-event-parse.o
 In file included from util/trace-event-parse.c:32:
 util/util.h:43:1: error: "_XOPEN_SOURCE" redefined

So remove them.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/perfcounters into perfcounters/core

This adds support for tracing callchains for powerpc, both 32-bit
and 64-bit, and both in the kernel and userspace, from PMU interrupt
context.

The first three entries stored for each callchain are the NIP (next
instruction pointer), LR (link register), and the contents of the LR
save area in the second stack frame (the first is ignored because the
ABI convention on powerpc is that functions save their return address
in their caller's stack frame).  Because leaf functions don't have to
save their return address (LR value) and don't have to establish a
stack frame, it's possible for either or both of LR and the second
stack frame's LR save area to have valid return addresses in them.
This is basically impossible to disambiguate without either reading
the code or looking at auxiliary information such as CFI tables.
Since we don't want to do either of those things at interrupt time,
we store both LR and the second stack frame's LR save area.

Once we get past the second stack frame, there is no ambiguity; all
return addresses we get are reliable.

For kernel traces, we check whether they are valid kernel instruction
addresses and store zero instead if they are not (rather than
omitting them, which would make it impossible for userspace to know
which was which).  We also store zero instead of the second stack
frame's LR save area value if it is the same as LR.

For kernel traces, we check for interrupt frames, and for user traces,
we check for signal frames.  In each case, since we're starting a new
trace, we store a PERF_CONTEXT_KERNEL/USER marker so that userspace
knows that the next three entries are NIP, LR and the second stack frame
for the interrupted context.

We read user memory with __get_user_inatomic.  On 64-bit, if this
PMU interrupt occurred while interrupts are soft-disabled, and
there is no MMU hash table entry for the page, we will get an
-EFAULT return from __get_user_inatomic even if there is a valid
Linux PTE for the page, since hash_page isn't reentrant.  Thus we
have code here to read the Linux PTE and access the page via the
kernel linear mapping.  Since 64-bit doesn't use (or need) highmem
there is no need to do kmap_atomic.  On 32-bit, we don't do soft
interrupt disabling, so this complication doesn't occur and there
is no need to fall back to reading the Linux PTE, since hash_page
(or the TLB miss handler) will get called automatically if necessary.

Note that we cannot get PMU interrupts in the interval during
context switch between switch_mm (which switches the user address
space) and switch_to (which actually changes current to the new
process).  On 64-bit this is because interrupts are hard-disabled
in switch_mm and stay hard-disabled until they are soft-enabled
later, after switch_to has returned.  So there is no possibility
of trying to do a user stack trace when the user address space is
not current's address space.
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This provides a mechanism to allow the perf_counters code to access
user memory in a PMU interrupt routine.  Such an access can cause
various kinds of interrupt: SLB miss, MMU hash table miss, segment
table miss, or TLB miss, depending on the processor.  This commit
only deals with 64-bit classic/server processors, which use an MMU
hash table.  32-bit processors are already able to access user memory
at interrupt time.  Since we don't soft-disable on 32-bit, we avoid
the possibility of reentering hash_page or the TLB miss handlers,
since they run with interrupts disabled.

On 64-bit processors, an SLB miss interrupt on a user address will
update the slb_cache and slb_cache_ptr fields in the paca.  This is
OK except in the case where a PMU interrupt occurs in switch_slb,
which also accesses those fields.  To prevent this, we hard-disable
interrupts in switch_slb.  Interrupts are already soft-disabled at
this point, and will get hard-enabled when they get soft-enabled
later.

This also reworks slb_flush_and_rebolt: to avoid hard-disabling twice,
and to make sure that it clears the slb_cache_ptr when called from
other callers than switch_slb, the existing routine is renamed to
__slb_flush_and_rebolt, which is called by switch_slb and the new
version of slb_flush_and_rebolt.

Similarly, switch_stab (used on POWER3 and RS64 processors) gets a
hard_irq_disable() to protect the per-cpu variables used there and
in ste_allocate.

If a MMU hashtable miss interrupt occurs, normally we would call
hash_page to look up the Linux PTE for the address and create a HPTE.
However, hash_page is fairly complex and takes some locks, so to
avoid the possibility of deadlock, we check the preemption count
to see if we are in a (pseudo-)NMI handler, and if so, we don't call
hash_page but instead treat it like a bad access that will get
reported up through the exception table mechanism.  An interrupt
whose handler runs even though the interrupt occurred when
soft-disabled (such as the PMU interrupt) is considered a pseudo-NMI
handler, which should use nmi_enter()/nmi_exit() rather than
irq_enter()/irq_exit().
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

On 32-bit systems with 64-bit PTEs, the PTEs have to be written in two
32-bit halves.  On SMP we write the higher-order half and then the
lower-order half, with a write barrier between the two halves, but on
UP there was no particular ordering of the writes to the two halves.

This extends the ordering that we already do on SMP to the UP case as
well.  The reason is that with the perf_counter subsystem potentially
accessing user memory at interrupt time to get stack traces, we have
to be careful not to create an incorrect but apparently valid PTE even
on UP.
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

In general, code in perf_counter.c that is called through an
IPI checks, for per-task counters, that the counter's task is
still the current task.  This is to handle the race condition
where the cpu switches from the task we want to another task in
the interval between sending the IPI and the IPI arriving and
being handled on the target CPU.

For some reason, __perf_counter_read is missing this check, yet
there is no reason why the race condition can't occur.  This
adds a check that the current task is the one we want.  If it
isn't, we just return.  In that case the counter->count value
should be up to date, since it will have been updated when the
counter was scheduled out, which must have happened since the
IPI was sent.

I don't have an example of an actual failure due to this race,
but it seems obvious that it could occur and we need to guard
against it.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <19076.63614.277861.368125@drongo.ozlabs.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Rename it to examples.txt to avoid the perf-*.txt pattern in
the Makefile, otherwise 'make doc' fails because
perf-examples.txt is not formatted to be a man page:

 ERROR: perf-examples.txt: line 1: manpage document title is mandatory
Signed-off-by: NCarlos R. Mafra <crmafra@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Librarize trace_event() helper so that perf trace can use it
too. Also clean up the debug.h includes a bit.

It's not good to have it included in perf.h because it doesn't
make it flexible against other headers it may need (headers
that can also depend on perf.h and then create a recursive
header dependency).
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250453149-664-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Librarize the sample type and attr fetching from perf data file
headers so that we can also use it from perf trace.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250448997-30715-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Annotate and report share the same flags to filter events
considering their context (kernel, user, hypervisor).

Both tools have their own definitions of these flags. Factorize
them out into the event headers file.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250445414-29237-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We have two users of dprintf: report and annotate. Another one
is coming with perf trace. Then factorize it into the debug
file.

While at it, rename dprintf() to dump_printf() so that it
doesn't conflicts with its libc homograph.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250443461-28130-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The soon coming perf trace needs to use printf with dynamically
built formats.

But we are using -Wformat=2 which is a shortcut for the
following set: -Wformat -Wformat-security -Wformat-y2k
-Wformat-nonliteral

-Wformat-nonliteral warns when it can't check formats because
they are not builtin constant strings, but we want to feature
dynamic formats. What we want instead is Wformat=2 minus
-Wformat-nonliteral, which is what this patch does.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250437927-25490-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Up our defences a bit.
Suggested-by: NArjan van de Ven <arjan@infradead.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Related to a shadowed variable bug fix Valdis Kletnieks noticed
that perf does not get built with -Wshadow, which could have
helped us avoid the bug.

So enable -Wshadow and also enable the following warnings on
perf builds, in addition to the already enabled -Wall -Wextra
-std=gnu99 warnings:

 -Wcast-align
 -Wformat=2
 -Wshadow
 -Winit-self
 -Wpacked
 -Wredundant-decls
 -Wstack-protector
 -Wstrict-aliasing=3
 -Wswitch-default
 -Wswitch-enum
 -Wno-system-headers
 -Wundef
 -Wvolatile-register-var
 -Wwrite-strings
 -Wbad-function-cast
 -Wmissing-declarations
 -Wmissing-prototypes
 -Wnested-externs
 -Wold-style-definition
 -Wstrict-prototypes
 -Wdeclaration-after-statement

And change/fix the perf code to build cleanly under GCC 4.3.2.

The list of warnings enablement is rather arbitrary: it's based
on my (quick) reading of the GCC manpages and trying them on
perf.

I categorized the warnings based on individually enabling them
and looking whether they trigger something in the perf build.
If i liked those warnings (i.e. if they trigger for something
that arguably could be improved) i enabled the warning.

If the warnings seemed to come from language laywers spamming
the build with tons of nuisance warnings i generally kept them
off. Most of the sign conversion related warnings were in
this category. (A second patch enabling some of the sign
warnings might be welcome - sign bugs can be nasty.)

I also kept warnings that seem to make sense from their manpage
description and which produced no actual warnings on our code
base. These warnings might still be turned off if they end up
being a nuisance.

I also left out a few warnings that are not supported in older
compilers.

[ Note that these changes might break the build on older
  compilers i did not test, or on non-x86 architectures that
  produce different warnings, so more testing would be welcome. ]

Reported-by: Valdis.Kletnieks@vt.edu
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Factorize the thread management code used by perf-annotate and
perf-report in dedicated source and header files.

v2: pass last_match by address so that it can actually be
modified.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250245313-6995-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:
	kernel/perf_counter.c

Merge reason: update to latest upstream (-rc6) and resolve
              the conflict with urgent fixes.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Just to make it clear that these are _not_ generic event
structures but do rely on the counter configuration.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey J Ashford <cjashfor@us.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
LKML-Reference: <20090813103655.334194326@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We were using 'fd' locally, but there was a global 'fd' too, so
when converting from open to fopen the test made against fd
should be made against 'fp', but since we have that global
it didnt get discovered ...
Reported-by: NUlrich Drepper <drepper@redhat.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20090814182632.GF3490@ghostprotocols.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

free_irq() can remove an irqaction while the corresponding interrupt
is in progress, but free_irq() sets action->thread to NULL
unconditionally, which might lead to a NULL pointer dereference in
handle_IRQ_event() when the hard interrupt context tries to wake up
the handler thread.

Prevent this by moving the thread stop after synchronize_irq(). No
need to set action->thread to NULL either as action is going to be
freed anyway.

This fixes a boot crash reported against preempt-rt which uses the
mainline irq threads code to implement full irq threading.

[ tglx: removed local irqthread variable ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf_counter: Report the cloning task as parent on perf_counter_fork()
  perf_counter: Fix an ipi-deadlock
  perf: Rework/fix the whole read vs group stuff
  perf_counter: Fix swcounter context invariance
  perf report: Don't show unresolved DSOs and symbols when -S/-d is used
  perf tools: Add a general option to enable raw sample records
  perf tools: Add a per tracepoint counter attribute to get raw sample
  perf_counter: Provide hw_perf_counter_setup_online() APIs
  perf list: Fix large list output by using the pager
  perf_counter, x86: Fix/improve apic fallback
  perf record: Add missing -C option support for specifying profile cpu
  perf tools: Fix dso__new handle() to handle deleted DSOs
  perf tools: Fix fallback to cplus_demangle() when bfd_demangle() is not available
  perf report: Show the tid too in -D
  perf record: Fix .tid and .pid fill-in when synthesizing events
  perf_counter, x86: Fix generic cache events on P6-mobile CPUs
  perf_counter, x86: Fix lapic printk message

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Fix handling of bad requeue syscall pairing
  futex: Fix compat_futex to be same as futex for REQUEUE_PI
  locking, sched: Give waitqueue spinlocks their own lockdep classes
  futex: Update futex_q lock_ptr on requeue proxy lock

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix oops in identify_cpu() on CPUs without CPUID
  x86: Clear incorrectly forced X86_FEATURE_LAHF_LM flag
  x86, mce: therm_throt - change when we print messages
  x86: Add reboot quirk for every 5 series MacBook/Pro

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (22 commits)
  ocfs2: Fix possible deadlock when extending quota file
  ocfs2: keep index within status_map[]
  ocfs2: Initialize the cluster we're writing to in a non-sparse extend
  ocfs2: Remove redundant BUG_ON in __dlm_queue_ast()
  ocfs2/quota: Release lock for error in ocfs2_quota_write.
  ocfs2: Define credit counts for quota operations
  ocfs2: Remove syncjiff field from quota info
  ocfs2: Fix initialization of blockcheck stats
  ocfs2: Zero out padding of on disk dquot structure
  ocfs2: Initialize blocks allocated to local quota file
  ocfs2: Mark buffer uptodate before calling ocfs2_journal_access_dq()
  ocfs2: Make global quota files blocksize aligned
  ocfs2: Use ocfs2_rec_clusters in ocfs2_adjust_adjacent_records.
  ocfs2: Fix deadlock on umount
  ocfs2: Add extra credits and access the modified bh in update_edge_lengths.
  ocfs2: Fail ocfs2_get_block() immediately when a block needs allocation
  ocfs2: Fix error return in ocfs2_write_cluster()
  ocfs2: Fix compilation warning for fs/ocfs2/xattr.c
  ocfs2: Initialize count in aio_write before generic_write_checks
  ocfs2: log the actual return value of ocfs2_file_aio_write()
  ...

* 'for-linus' of git://neil.brown.name/md:
  md: allow upper limit for resync/reshape to be set when array is read-only
  md/raid5: Properly remove excess drives after shrinking a raid5/6
  md/raid5: make sure a reshape restarts at the correct address.
  md/raid5: allow new reshape modes to be restarted in the middle.
  md: never advance 'events' counter by more than 1.
  Remove deadlock potential in md_open

* 'sh/for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: fix i2c init order on ap325rxa V2
  sh: fix i2c init order on Migo-R V2
  sh: convert processor device setup functions to arch_initcall()

kernel_sendpage() does the proper default case handling for when the
socket doesn't have a native sendpage implementation.

Now, arguably this might be something that we could instead solve by
just specifying that all protocols should do it themselves at the
protocol level, but we really only care about the common protocols.
Does anybody really care about sendpage on something like Appletalk? Not
likely.
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NJulien TINNES <julien@cr0.org>
Acked-by: NTavis Ormandy <taviso@sdf.lonestar.org>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A bug in (9f498cc5: perf_counter: Full task tracing) makes
profiling multi-threaded apps it go belly up.

[ output as: (PID:TID):(PPID:PTID) ]

 # ./perf report -D | grep FORK
0x4b0 [0x18]: PERF_EVENT_FORK: (3237:3237):(3236:3236)
0xa10 [0x18]: PERF_EVENT_FORK: (3237:3238):(3236:3236)
0xa70 [0x18]: PERF_EVENT_FORK: (3237:3239):(3236:3236)
0xad0 [0x18]: PERF_EVENT_FORK: (3237:3240):(3236:3236)
0xb18 [0x18]: PERF_EVENT_FORK: (3237:3241):(3236:3236)

Shows us that the test (27d028de perf report: Update for the new
FORK/EXIT events) in builtin-report.c:

        /*
         * A thread clone will have the same PID for both
         * parent and child.
         */
        if (thread == parent)
                return 0;

Will clearly fail.

The problem is that perf_counter_fork() reports the actual
parent, instead of the cloning thread.

Fixing that (with the below patch), yields:

 # ./perf report -D | grep FORK
0x4c8 [0x18]: PERF_EVENT_FORK: (1590:1590):(1589:1589)
0xbd8 [0x18]: PERF_EVENT_FORK: (1590:1591):(1590:1590)
0xc80 [0x18]: PERF_EVENT_FORK: (1590:1592):(1590:1590)
0x3338 [0x18]: PERF_EVENT_FORK: (1590:1593):(1590:1590)
0x66b0 [0x18]: PERF_EVENT_FORK: (1590:1594):(1590:1590)

Which both makes more sense and doesn't confuse perf report
anymore.
Reported-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: paulus@samba.org
Cc: Anton Blanchard <anton@samba.org>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <1250172882.5241.62.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

perf_pending_counter() is called from IRQ context and will call
perf_counter_disable(), however perf_counter_disable() uses
smp_call_function_single() which doesn't fancy being used with
IRQs disabled due to IPI deadlocks.

Fix this by making it use the local __perf_counter_disable()
call and teaching the counter_sched_out() code about pending
disables as well.

This should cover the case where a counter migrates before the
pending queue gets processed.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey J Ashford <cjashfor@us.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
LKML-Reference: <20090813103655.244097721@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Replace PERF_SAMPLE_GROUP with PERF_SAMPLE_READ and introduce
PERF_FORMAT_GROUP to deal with group reads in a more generic
way.

This allows you to get group reads out of read() as well.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey J Ashford <cjashfor@us.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
LKML-Reference: <20090813103655.117411814@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>