Feature bitmap is declared as an array of unsigned longs -- not good
since its size can differ between the host that generated the data file
and the host analyzing the file.

We need to handle endianness, but we don't know the size of the unsigned
long where the file was generated. Take a best guess at determining it:
try 64-bit swap first (ie., file created on a 64-bit host), and check if
the hostname feature bit is set (this feature bit is forced on as of
fbe96f29).  If the bit is not, undo the 64-bit swap and try a 32-bit
swap. If the hostname bit is still not set (e.g., older data file), punt
and fallback to the original behavior -- clearing all feature bits and
setting buildid.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1318980841-12616-1-git-send-email-dsahern@gmail.comSigned-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Following a prelink run mapped files for long running processes can show
as deleted. The current message suggests restarting long running
processes. Add to that a suggestion that prelink might be the cause.

Old message:
/lib64/libc-2.14.so was updated, restart the long running
 apps that use it!

New message:
/lib64/libc-2.14.so was updated (is prelink enabled?).
  Restart the long running apps that use it!

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1318985085-20776-1-git-send-email-dsahern@gmail.comSigned-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

"perf script -v" emits:

unknown feature 3, continuing...
unknown feature 4, continuing...
unknown feature 5, continuing...
unknown feature 6, continuing...
unknown feature 7, continuing...
unknown feature 8, continuing...
unknown feature 9, continuing...
unknown feature 10, continuing...
unknown feature 11, continuing...
unknown feature 12, continuing...
unknown feature 13, continuing...
unknown feature 14, continuing...

These are all new features added by fbe96f29. Update
perf_file_section__process to know they are valid feature ids.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1318984464-20650-1-git-send-email-dsahern@gmail.comSigned-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Now that we dynamicly add entries on the timer we need to not only
traverse all entries when the user zooms into threads and/or DSOs, but
as well after that apply it to the new batches of hist entries in
hists__collapse_resort.
Reported-by: NMike Galbraith <efault@gmx.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-zustn633c7hnrae94x6nld1p@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since with dynamic addition of new hist entries we need to apply those
filters as we merge new batches of hist_entry instances, for instance in
perf top.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-zjhhf8kh9w1buty9p10od6rz@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

So slang after all _has_ a 'default' color, call me color blind. Change
the default to it.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Link: http://lkml.kernel.org/n/tip-1dfxivxv0jhwldpds3v4zla2@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

And like it was in the old top.

Another change so that the familiarity with the old visual is maintained.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ypmyx9p0ah4byqaygrnb09x8@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Just use as a starting point the "[colors]" section of
tools/perf/Documentation/perfconfig.example.

Changed the colors to be the ones in the old perf tool if used in a green on
black xterm.

The next patches should allow using the colors configured for the xterm.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-3vqmyerkaqltqolmnlehonew@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

That was just filling the screen with blue, even if not a crash, not
something pleasant nor useful ;-)

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-58znjqvan9b1mv5pojxboidg@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We can't have color correctly set there because in libslang (and in a future
GUI) the colors must be set on a separate function call, so move that part to a
separate function and make the stdio fprintf function call it.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-jpgy42438ce9tgbqppm397lq@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The selection and scroll bar are really needed only when the user starts
navigating, before that it just provide distractions.

This also brings the initial screen to look more like the stdio UI,
which more people are used to.

The new code is flexible enough that menu like browsers can opt out and
start with those UI elements.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-jfgok30kkerpfw8wtcltgy6z@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Resetting the terminal to a sane state.
Reported-by: NIngo Molnar <mingo@elte.hu>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-myu44ujofadcy3y6an2mk383@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The navigation keys were missing (UP, DOWN arrows, etc).

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-3pnln0bws5v0yoqwd3f020nx@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When compiling an i386_defconfig kernel with
gcc-4.6.1-9.fc15.i686, I noticed a warning about the asm operand
for test_bit in kprobes' can_boost. I discovered that this
caused only the first long of twobyte_is_boostable[] to be
output.

Jakub filed and fixed gcc PR50571 to correct the warning and
this output issue.  But to solve it for less current gcc, we can
make kprobes' twobyte_is_boostable[] volatile, and it won't be
optimized out.

Before:

    CC      arch/x86/kernel/kprobes.o
  In file included from include/linux/bitops.h:22:0,
                   from include/linux/kernel.h:17,
                   from [...]/arch/x86/include/asm/percpu.h:44,
                   from [...]/arch/x86/include/asm/current.h:5,
                   from [...]/arch/x86/include/asm/processor.h:15,
                   from [...]/arch/x86/include/asm/atomic.h:6,
                   from include/linux/atomic.h:4,
                   from include/linux/mutex.h:18,
                   from include/linux/notifier.h:13,
                   from include/linux/kprobes.h:34,
                   from arch/x86/kernel/kprobes.c:43:
  [...]/arch/x86/include/asm/bitops.h: In function ‘can_boost.part.1’:
  [...]/arch/x86/include/asm/bitops.h:319:2: warning: use of memory input without lvalue in asm operand 1 is deprecated [enabled by default]

  $ objdump -rd arch/x86/kernel/kprobes.o | grep -A1 -w bt
       551:	0f a3 05 00 00 00 00 	bt     %eax,0x0
                          554: R_386_32	.rodata.cst4

  $ objdump -s -j .rodata.cst4 -j .data arch/x86/kernel/kprobes.o

  arch/x86/kernel/kprobes.o:     file format elf32-i386

  Contents of section .data:
   0000 48000000 00000000 00000000 00000000  H...............
  Contents of section .rodata.cst4:
   0000 4c030000                             L...

Only a single long of twobyte_is_boostable[] is in the object
file.

After, with volatile:

  $ objdump -rd arch/x86/kernel/kprobes.o | grep -A1 -w bt
       551:	0f a3 05 20 00 00 00 	bt     %eax,0x20
                          554: R_386_32	.data

  $ objdump -s -j .rodata.cst4 -j .data arch/x86/kernel/kprobes.o

  arch/x86/kernel/kprobes.o:     file format elf32-i386

  Contents of section .data:
   0000 48000000 00000000 00000000 00000000  H...............
   0010 00000000 00000000 00000000 00000000  ................
   0020 4c030000 0f000200 ffff0000 ffcff0c0  L...............
   0030 0000ffff 3bbbfff8 03ff2ebb 26bb2e77  ....;.......&..w

Now all 32 bytes are output into .data instead.
Signed-off-by: NJosh Stone <jistone@redhat.com>
Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Link: http://lkml.kernel.org/r/1318899645-4068-1-git-send-email-jistone@redhat.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core

Atomic64 is now a valid type in Linux. Archs that do not have their own
version of atomic64 operators are to use the generic operations.

The m32r architecture needs to define GENERIC_ATOMIC64.

Link: http://lkml.kernel.org/r/20111013085936.GA13046@elte.hu
Link: http://lkml.kernel.org/r/1318516816.12224.12.camel@gandalf.stny.rr.com
Link: http://lkml.kernel.org/r/20111017185440.GB5545@elte.huAcked-by: NHirokazu Takata <takata@linux-m32r.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core

    CC util/ui/browsers/annotate.o
In file included from util/ui/browsers/annotate.c:2:0:
util/ui/browsers/../helpline.h:9:42: error: expected declaration
specifiers or ‘...’ before ‘va_list’
    CC util/ui/browsers/hists.o
make: *** [util/ui/browsers/annotate.o] Error 1
make: *** Waiting for unfinished jobs....
Signed-off-by: NMike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/n/tip-9vefl2807smi7t4luhs00tg6@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We were not recognizing 'E' as a hotkey due to a bug introduced when
switching to the new, hist_entry based top. Fix it by returning that 'E'
is mapped if evlist->nr_entries > 1.
Reported-by: NMike Galbraith <efault@gmx.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-zcx055vnhagddvqlaqxvdhtb@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The new decay routine (__hists__decay_entries) wasn't being passed the
toggles, fix it.
Reported-by: NMike Galbraith <efault@gmx.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-hg6m0mi1colket982oq9hhly@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The readlink function doesn't guarantee that a '\0' will be put at the
end of the provided buffer if there is no space left.

No need to do "buf[len] = '\0';" since the buffer is allocated with
zalloc().

Link: http://lkml.kernel.org/r/4E986ABF.9040706@intra2net.comSigned-off-by: NThomas Jarosch <thomas.jarosch@intra2net.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Just press 'S' on any assembly line and the source code will be hidden
while the current line remains selected. Press 'S' again to show them
back.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-efmxm5etouebb7es0kkyqqwa@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Its becoming common to allow the user to filter out parts of the data
structure being browsed, like already done in the hists browser and in
the annotate browser in the next commit, so provide it directly in the
ui_browser class list_head helpers.

More work required to move the equivalent routines found now in the
hists browser to the rb_tree helpers.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-jk7danyt1d9ji4e3o2xuthpn@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We lost that functionality on ed7e5662, restore it.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-z8eb8af2x46x42lgpn1ustid@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

With underlying dynamic data structures we need to invalidate pointers
to them after a timer, as that entry may have vanished (decayed in top,
for instance).

I forgot about browser_ui->top. Fix it by resetting it to null after a
timer. The seek operation from SEEK_SET will then set it to a valid
entry because it starts from rb_first(&hists->entries).
Reported-by: NIngo Molnar <mingo@elte.hu>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2ssjm0ouh9tsz4dwkcu7c40n@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The trace_pipe_raw handler holds a cached page from the time the file
is opened to the time it is closed. The cached page is used to handle
the case of the user space buffer being smaller than what was read from
the ring buffer. The left over buffer is held in the cache so that the
next read will continue where the data left off.

After EOF is returned (no more data in the buffer), the index of
the cached page is set to zero. If a user app reads the page again
after EOF, the check in the buffer will see that the cached page
is less than page size and will return the cached page again. This
will cause reading the trace_pipe_raw again after EOF to return
duplicate data, making the output look like the time went backwards
but instead data is just repeated.

The fix is to not reset the index right after all data is read
from the cache, but to reset it after all data is read and more
data exists in the ring buffer.

Cc: stable <stable@kernel.org>
Reported-by: NJeremy Eder <jeder@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

tracing_enabled option is deprecated.
To start/stop tracing, write to /sys/kernel/debug/tracing/tracing_on
without tracing_enabled. This patch is based on Linux 3.1.0-rc1
Signed-off-by: NGeunsik Lim <geunsik.lim@samsung.com>
Link: http://lkml.kernel.org/r/1313127022-23830-1-git-send-email-leemgs1@gmail.comSigned-off-by: NSteven Rostedt <rostedt@goodmis.org>

When using multiple events the 'top' and 'report' tools will first
present the user with a menu to choose the event to browse.

After that the user can either press <- to go back to the menu and
choose another event or instead press TAB to go the next event without
having to go back to the menu or shift-TAB (UNTAB) to go the previous
event, useful to quickly visually see if multiple events are correlated.

The handling of each hists browser return was broken by the ed7e5662,
that combined both switches, the first that was for choosing the event
and the second that was for checking if switching to the next event
without passing thru the events menu.

Repeat with me: Don't be clever like that.

Fix it by moving the switch to right after the call to the hists
browser, making abundantly clear that the two switches are unrelated.

This also fixes a compiler warning about the 'pos' variable being
possibly used unitialized.
Reported-by: NIngo Molnar <mingo@elte.hu>
[ committer note: the line above is for the compiler warning ]
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ujxkbvj9vy8w6xe2op5m51tb@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We were removing only when using a --sort order that needs collapsing,
while we also use it in the threaded case, causing memory corruption
because we were scribbling freed hist entries, oops.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-k16fb4jsulr7x0ixv43amb6d@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Users (hist_browser, etc) should just handle all keys, discarding the
ones they don't handle.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-fjouann12v2k58t6vdd2wawb@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To do that we needed to stop using newtForm, as we don't want libnewt to
catch the xterm resize signal.

Remove some more newt calls and instead use the underlying libslang
directly. In time tools/perf will use just libslang.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-h1824yjiru5n2ivz4bseizwj@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch, relative to tip/master, makes perf compile when
NO_NEWT_SUPPORT is set.  It also fixes the line formatting to fit 80
columns.

Please test with NO_NEWT.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20111012120328.GA1619@quadSigned-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Just let it there till the user exits the annotation browser.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-nmaxuzreqhm5k10t2co5sk9a@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core

In browsers that access dynamic underlying data structures, like in the
hists browser and its hist_entry rb_tree, we need to revalidate any
reference to the underlying data structure, because they can have gone
away, decayed.

This fixes a problem where after a while the top entries get behind the
top of the screen, i.e. the top_idx stays at 0, which means it is at the
first entry in the rb_tree when in fact it wasn't because the
browser->top didn't got revalidated after the timer ran and the
underlying data structure got updated.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-mhje66qssdko24q67a2lhlho@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When doing intense tracing, the kmalloc inside trace_marker can
introduce side effects to what is being traced.

As trace_marker() is used by userspace to inject data into the
kernel ring buffer, it needs to do so with the least amount
of intrusion to the operations of the kernel or the user space
application.

As the ring buffer is designed to write directly into the buffer
without the need to make a temporary buffer, and userspace already
went through the hassle of knowing how big the write will be,
we can simply pin the userspace pages and write the data directly
into the buffer. This improves the impact of tracing via trace_marker
tremendously!

Thanks to Peter Zijlstra and Thomas Gleixner for pointing out the
use of get_user_pages_fast() and kmap_atomic().
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Suggested-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

As the function tracer is very intrusive, lots of self checks are
performed on the tracer and if something is found to be strange
it will shut itself down keeping it from corrupting the rest of the
kernel. This shutdown may still allow functions to be traced, as the
tracing only stops new modifications from happening. Trying to stop
the function tracer itself can cause more harm as it requires code
modification.

Although a WARN_ON() is executed, a user may not notice it. To help
the user see that something isn't right with the tracing of the system
a big warning is added to the output of the tracer that lets the user
know that their data may be incomplete.
Reported-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>