It better propagate errors, also if we do a simple:

[root@doppio linux-2.6-tip]# perf record -R -a -f sleep 3s ;
perf trace [ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.182 MB perf.data (~7972 samples) ]
Fatal: not an trace data file
[root@doppio linux-2.6-tip]#

That is what is expected, right? I.e. as we didn't specify any
tracepoint event via -e, it should gracefully bail out and not
SEGFAULT.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frédéric 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: <1258821086-11521-3-git-send-email-acme@infradead.org>
[ Fixed the error messages some more ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258821086-11521-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We better call this routine after both the kernel and modules
are loaded, because as it was if there weren't modules it would not
be called, resulting in kernel_map->end remaining at zero, so no
map would be found and consequently the kernel symtab wouldn't
get loaded, i.e. no kernel symbols would be resolved.

Also this fixes another case, that is when we _have_ modules,
but the last map would have its ->end address not set before we
loaded its symbols, which would never happen because ->end was
not set.
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258821086-11521-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch fixes the default watermark value for the sampling
buffer. With the existing calculation (watermark =
max(PAGE_SIZE, max_size / 2)), no notification was ever received
when the buffer was exactly 1 page. This was because you would
never cross the threshold (there is no partial samples).

In certain configuration, there was no possibilty detecting the
problem because there was not enough space left to store the
LOST record.In fact, there may be a more generic problem here.
The kernel should ensure that there is alaways enough space to
store one LOST record.

This patch sets the default watermark to half the buffer size.
With such limit, we are guaranteed to get a notification even
with a single page buffer assuming no sample is bigger than a
page.
Signed-off-by: NStephane Eranian <eranian@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212509.344964101@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
LKML-Reference: <1256302576-6169-1-git-send-email-eranian@gmail.com>

We should hold event->child_mutex when iterating the inherited
counters, we should hold ctx->mutex when iterating siblings.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212509.251030114@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Properly account the full hierarchy of counters for both the
count (we already did so) and the scale times (new).
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212509.153379276@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Most sites updating ctx->time and event times do so under
ctx->lock, make sure they all do.

This was made possible by removing the __perf_event_read() call
from __perf_event_sync_stat(), which already had this lock
taken.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212509.102316434@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

cpuctx is always active, task context is always active for
current

the previous condition verifies that if its a task context its
for current, hence we can assume ctx->is_active.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212509.000272254@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Removes constraints from __perf_event_read() by leaving it with
a single callsite; this callsite had ctx->lock held, the other
one does not.

Removes some superfluous code from __perf_event_sync_stat().
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.918544317@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Both callers actually have IRQs disabled, no need doing so
again.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.863685796@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove an update_context_time() call from the
perf_event_task_sched_out() path and into the branch its needed.

The call was both superfluous, because __perf_event_sched_out()
already does it, and wrong, because it was done without holding
ctx->lock.

Place it in perf_event_sync_stat(), which is the only place it
is needed and which does already hold ctx->lock.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.779516394@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

As Corey reported, the total_enabled and total_running times
could occasionally be 0, even though there were events counted.

It turns out this is because we record the times before reading
the counter while the latter updates the times.

This patch corrects that.

While looking at this code I found that there is a lot of
locking iffyness around, the following patches correct most of
that.
Reported-by: NCorey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.685559857@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove a rcu_read_{,un}lock() pair and a few conditionals.

We can remove the rcu_read_lock() by increasing the scope of one
in the calling function.

We can do away with the system_state check if the machine still
boots after this patch (seems to be the case).

We can do away with the list_empty() check because the bare
list_for_each_entry_rcu() reduces to that now that we've removed
everything else.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.606459548@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove a rcu_read_{,un}lock() pair and a few conditionals.

We can remove the rcu_read_lock() by increasing the scope of one
in the calling function.

We can do away with the system_state check if the machine still
boots after this patch (seems to be the case).

We can do away with the list_empty() check because the bare
list_for_each_entry_rcu() reduces to that now that we've removed
everything else.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.527608793@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove a rcu_read_{,un}lock() pair and a few conditionals.

We can remove the rcu_read_lock() by increasing the scope of one
in the calling function.

We can do away with the system_state check if the machine still
boots after this patch (seems to be the case).

We can do away with the list_empty() check because the bare
list_for_each_entry_rcu() reduces to that now that we've removed
everything else.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.452227115@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove a rcu_read_{,un}lock() pair and a few conditionals.

We can remove the rcu_read_lock() by increasing the scope of one
in the calling function.

We can do away with the system_state check if the machine still
boots after this patch (seems to be the case).

We can do away with the list_empty() check because the bare
list_for_each_entry_rcu() reduces to that now that we've removed
everything else.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.378188589@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Avoid the rather expensive perf_swevent_set_period() if we know
we have to sample every single event anyway.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.299508332@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

in-kernel perf users might wish to have custom actions on the
sample interrupt.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212508.222339539@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

So that the user have a clearer indication about the source of
the symbols, as we only state buildid mismatches in verbose
mode, because 'perf top' would overwrite such warning anyway.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258757489-5978-6-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

E.g.:

[root@doppio linux-2.6-tip]# perf top -v --vmlinux
../build/tip/vmlinux > /dev/null build_id in vmlinux is
e96699725a47413a50c231864a8e7a8ced40a31b while expected is
18e7cc53db62a7d35e9d6f6c9ddc23017d38ee9a, ignoring it

I.e. perf top was told to use a vmlinux file that is not the one
currently running on the machine, it ignores it and falls back
to using /proc/kallsyms.

This solves many, at first, mysterious results when people have
a stale vmlinux file while keeping the default of trying to use
the vmlinux file in the current directory in things like 'perf
annotate' where the DWARF info is required and thus we can't use
just /proc/kallsyms.

Modules buildids are already being checked as of the previous
changeset in this series, because we are using the default
dso__load routine, that will look at a series of places looking
for the best file with a matching buildid, starting in the
-debuginfo directories.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258757489-5978-5-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Just like we do with the other DSOs. This also simplifies the
kernel_maps setup process, now all that the tools need to do is
to call kernel_maps__init and the maps for the modules and
kernel will be created, then, later, when
kernel_maps__find_symbol() is used, it will also call
maps__find_symbol that already checks if the symtab was loaded,
loading it if needed.

Now if one does 'perf top --hide_kernel_symbols' we won't pay
the price of loading the (many) symbols in /proc/kallsyms or
vmlinux.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258757489-5978-4-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Will be used in more places.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258757489-5978-3-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In the kernel we have more than one notes section, so the linker
script combines all and puts them into a ".notes" combined
section. So we need to look at both sections and also traverse
them looking at multiple GElf_Nhdr entries till we find the one
we want, with the build_id.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258757489-5978-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

It should just load kernel symbols, not load the list of
modules. There are more stuff to move to other routines, but
lets do it in several steps.

End goal is to be able to defer symbol table loading till we
find a hit for that map address range. So that the kernel &
modules are handled just like all the other DSOs in the system.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258757489-5978-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:
	arch/x86/kernel/kprobes.c
	kernel/trace/Makefile

Merge reason: hw-breakpoints perf integration is looking
              good in testing and in reviews, plus conflicts
              are mounting up - so merge & resolve.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:
	tools/perf/util/symbol.c

Merge reason: this fix will get merged in .33, not .32, plus
              resolve the conflict.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This tool is mostly a perf version of kmemtrace-user.

The following information is provided by this tool:

 - the total amount of memory allocated and fragmentation per
   call-site

 - the total amount of memory allocated and fragmentation per
   allocation

 - total memory allocated and fragmentation in the collected
   dataset - ...

Sample output:

 # ./perf kmem record
 ^C
 # ./perf kmem --stat caller --stat alloc -l 10

 ------------------------------------------------------------------------------
 Callsite          | Total_alloc/Per |  Total_req/Per  |  Hit   | Fragmentation
 ------------------------------------------------------------------------------
 0xc052f37a        |   790528/4096   |   790528/4096   |    193 |    0.000%
 0xc0541d70        |   524288/4096   |   524288/4096   |    128 |    0.000%
 0xc051cc68        |   481600/200    |   481600/200    |   2408 |    0.000%
 0xc0572623        |   297444/676    |   297440/676    |    440 |    0.001%
 0xc05399f1        |    73476/164    |    73472/164    |    448 |    0.005%
 0xc05243bf        |    51456/256    |    51456/256    |    201 |    0.000%
 0xc0730d0e        |    31844/497    |    31808/497    |     64 |    0.113%
 0xc0734c4e        |    17152/256    |    17152/256    |     67 |    0.000%
 0xc0541a6d        |    16384/128    |    16384/128    |    128 |    0.000%
 0xc059c217        |    13120/40     |    13120/40     |    328 |    0.000%
 0xc0501ee6        |    11264/88     |    11264/88     |    128 |    0.000%
 0xc04daef0        |     7504/682    |     7128/648    |     11 |    5.011%
 0xc04e14a3        |     4216/191    |     4216/191    |     22 |    0.000%
 0xc05041ca        |     3524/44     |     3520/44     |     80 |    0.114%
 0xc0734fa3        |     2104/701    |     1620/540    |      3 |   23.004%
 0xc05ec9f1        |     2024/289    |     2016/288    |      7 |    0.395%
 0xc06a1999        |     1792/256    |     1792/256    |      7 |    0.000%
 0xc0463b9a        |     1584/144    |     1584/144    |     11 |    0.000%
 0xc0541eb0        |     1024/16     |     1024/16     |     64 |    0.000%
 0xc06a19ac        |      896/128    |      896/128    |      7 |    0.000%
 0xc05721c0        |      772/12     |      768/12     |     64 |    0.518%
 0xc054d1e6        |      288/57     |      280/56     |      5 |    2.778%
 0xc04b562e        |      157/31     |      154/30     |      5 |    1.911%
 0xc04b536f        |       80/16     |       80/16     |      5 |    0.000%
 0xc05855a0        |       64/64     |       36/36     |      1 |   43.750%
 ------------------------------------------------------------------------------

 ------------------------------------------------------------------------------
 Alloc Ptr         | Total_alloc/Per |  Total_req/Per  |  Hit   | Fragmentation
 ------------------------------------------------------------------------------
 0xda884000        |  1052672/4096   |  1052672/4096   |    257 |    0.000%
 0xda886000        |   262144/4096   |   262144/4096   |     64 |    0.000%
 0xf60c7c00        |    16512/128    |    16512/128    |    129 |    0.000%
 0xf59a4118        |    13120/40     |    13120/40     |    328 |    0.000%
 0xdfd4b2c0        |    11264/88     |    11264/88     |    128 |    0.000%
 0xf5274600        |     7680/256    |     7680/256    |     30 |    0.000%
 0xe8395000        |     5948/594    |     5464/546    |     10 |    8.137%
 0xe59c3c00        |     5748/479    |     5712/476    |     12 |    0.626%
 0xf4cd1a80        |     3524/44     |     3520/44     |     80 |    0.114%
 0xe5bd1600        |     2892/482    |     2856/476    |      6 |    1.245%
 ...               | ...             | ...             | ...    | ...
 ------------------------------------------------------------------------------

SUMMARY
=======
Total bytes requested: 2333626
Total bytes allocated: 2353712
Total bytes wasted on internal fragmentation: 20086
Internal fragmentation: 0.853375%

TODO:
- show sym+offset in 'callsite' column
- show cross node allocation stats
- collect more useful stats?
- ...
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: linux-mm@kvack.org <linux-mm@kvack.org>
LKML-Reference: <4B064AF5.9060208@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since some instructions are not decoded correctly by older
versions of objdump, it may cause false positive error in insn
decoder posttest.

This changes build error of insn decoder test to build warning.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
LKML-Reference: <20091116230631.5250.41579.stgit@harusame>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Propagate the error, that, interestingly, are already handled by
all callers :-)
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258649757-17554-3-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This time in perf_header__adds_write, propagating the do_write
error returns.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258649757-17554-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

And also don't call the constructor in it, this way it adheres
to the model the other methods follow.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258649757-17554-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[root@doppio linux-2.6-tip]# perf record -a -f sleep 3s ; perf
buildid-list | grep vmlinux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.171 MB perf.data (~7489
samples) ] 18e7cc53db62a7d35e9d6f6c9ddc23017d38ee9a vmlinux
[root@doppio linux-2.6-tip]#

Several refactorings were needed so that we can have symmetry
between dsos__load_modules() and dsos__load_kernel(), i.e. those
functions will respectively create and add to the dsos list the
loaded modules and kernel, with its buildids, but not load its
symbols. That is something the subcomands that need will have to
call dso__load_kernel_sym(), just like we do with modules with
dsos__load_module_sym()/dso__load_module_sym().

Next csets will actually use this info to stop producing bogus
results using mismatched vmlinux and .ko files.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Frédéric 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: <1258582853-8579-4-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[root@doppio linux-2.6-tip]# perf record -a sleep 2s;perf
buildid-list|tail [ perf record: Woken up 1 times to write data
] [ perf record: Captured and wrote 0.162 MB perf.data (~7078
samples) ] 881588fa57b3c1696bc91e5e804a11304f093535 [cfg80211]
4d47ce1da9d16bad00c962c072451b7c681e82df [snd_page_alloc]
5146377e89a7caac617f9782f1a02e46263d3a31 [rfkill]
2153b937bff0d345fea83b63a2e1d3138569f83d [i915]
4e6fb1bb97362e3ee4d306988b9ad6912d5fb9ae [drm_kms_helper]
f56ef2bf853e3a798f0d8d51f797622e5dc4420e [drm]
b0d157a3b5c4e017329ffc07c64623cd6ad65e95 [i2c_algo_bit]
8125374b905ef9fa8b65d98e166b008ad952f198 [i2c_core]
fc875c6e5a90e7b915e9d445d0efc859e1b2678c [video]
4b43c5006589f977e9762fdfc7ac1a92b72fca52 [output]
[root@doppio linux-2.6-tip]#

elfutils libdwfl/linux-kernel-modules.c was used as reference,
as suggested by Roland McGrath.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Frédéric 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: <1258582853-8579-3-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

No need for this struct and its allocations, we can just use the
->build_id member we already have in struct dso, then ask for it
to be read, and later traverse the dsos list, writing the
buildid table to the perf.data file.

As a bonus, one more die() function got killed.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258582853-8579-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When we read the build_id from the DSO name to then index into
/usr/lib/debug/.buildid/DSO_BUILD_ID[0:2]/DSO_BUILD_ID[2:], we
were jumping directly to the comparision with the buildid we
already have in dso->build_id (that came from the perf.data
build_id section, collected at perf record time)
unconditionally, even if we didn't had recorded it, and
furthermore, comparing a formatted buildid with a rawbuildid, yikes.

Fix it by deleting the dso__read_build_id() function, that was
really misdesigned anyway, and do the necessary checks and
correct comparison of raw buildids.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258582853-8579-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Defer to parse_source() time allocating it.

Now we use about this much memory:

 1724 root      20   0 42104  10m  940 S  0.0  0.4   0:00.23 perf
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258490282-1821-3-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Reducing memory consumption on a typical desktop machine:

From:

32710 root      20   0  172m 142m 1056 S  0.0  4.7   0:00.37
perf

To:

  420 root      20   0 47528  16m 1056 R  0.3  0.5   0:00.24 perf
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258490282-1821-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258490282-1821-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

E.g.

[root@doppio ~]# perf top -U
---------------------------------------------------------------------------
   PerfTop:     482 irqs/sec  kernel:100.0% [1000Hz cycles],  (all, 2 CPUs)
---------------------------------------------------------------------------
DSO: vmlinux
             samples  pcnt function
             _______ _____ _________________________

              471.00 47.9% read_hpet
               57.00  5.8% acpi_os_read_port
               30.00  3.1% hpet_next_event
               30.00  3.1% find_busiest_group
               22.00  2.2% schedule
               18.00  1.8% sched_clock_local
               14.00  1.4% _spin_lock_irqsave
               14.00  1.4% native_read_tsc
               13.00  1.3% trace_hardirqs_off
                9.00  0.9% fget_light
                9.00  0.9% ioread8
                8.00  0.8% do_sys_poll
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258479655-28662-3-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We pre-calculate the symbol name length, then after we sort the
entries to print, calculate the biggest one and use that for the
symbol name width justification, then use the
dso->long_name->len to justificate the DSO name, deciding whether
using the short or long name depending on how much space we have
on the terminal.

IOW give as much info to the user as the terminal width allows.
Suggested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric 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: <1258479655-28662-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>