We need to refactor code to be explicitely shared by the kernel and at
least the tools/ userspace programs, so, till we do that, copy the bare
minimum bitmap/bitops code needed by tools/perf.
Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
commit e9e94e3bd8
"perf trace: Ignore "overwrite" field if present in
/events/header_page" makes perf trace launching spurious warnings
about unexpected tokens read:
Warning: Error: expected type 6 but read 4
This change tries to handle the overcommit field in the header_page
file whenever this field is present or not.
The problem is that if this field is not present, we try to find it
and give up in the middle of the line when we realize we are actually
dealing with another field, which is the "data" one. And this failure
abandons the file pointer in the middle of the "data" description
line:
field: u64 timestamp; offset:0; size:8; signed:0;
field: local_t commit; offset:8; size:8; signed:1;
field: char data; offset:16; size:4080; signed:1;
^^^
Here
What happens next is that we want to read this line to parse the data
field, but we fail because the pointer is not in the beginning of the
line.
We could probably fix that by rewinding the pointer. But in fact we
don't care much about these headers that only concern the ftrace
ring-buffer. We don't use them from perf.
Just skip this part of perf.data, but don't remove it from recording
to stay compatible with olders perf.data
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
-f, -c 1, -R are now useless for trace events recording, moreover
-M is useless and event hurts.
Remove them from the documentation examples and from record scripts.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
First an example with the first internal test:
[acme@doppio linux-2.6-tip]$ perf test
1: vmlinux symtab matches kallsyms: Ok
So it run just one test, that is "vmlinux symtab matches kallsyms", and it was
successful.
If we run it in verbose mode, we'll see details about errors and extra warnings
for non-fatal problems:
[acme@doppio linux-2.6-tip]$ perf test -v
1: vmlinux symtab matches kallsyms:
--- start ---
Looking at the vmlinux_path (5 entries long)
No build_id in vmlinux, ignoring it
No build_id in /boot/vmlinux, ignoring it
No build_id in /boot/vmlinux-2.6.34-rc4-tip+, ignoring it
Using /lib/modules/2.6.34-rc4-tip+/build/vmlinux for symbols
Maps only in vmlinux:
ffffffff81cb81b1-ffffffff81e1149b 0 [kernel].init.text
ffffffff81e1149c-ffffffff9fffffff 0 [kernel].exit.text
ffffffffff600000-ffffffffff6000ff 0 [kernel].vsyscall_0
ffffffffff600100-ffffffffff6003ff 0 [kernel].vsyscall_fn
ffffffffff600400-ffffffffff6007ff 0 [kernel].vsyscall_1
ffffffffff600800-ffffffffffffffff 0 [kernel].vsyscall_2
Maps in vmlinux with a different name in kallsyms:
ffffffffff600000-ffffffffff6000ff 0 [kernel].vsyscall_0 in kallsyms as [kernel].0
ffffffffff600100-ffffffffff6003ff 0 [kernel].vsyscall_fn in kallsyms as:
*ffffffffff600100-ffffffffff60012f 0 [kernel].2
ffffffffff600400-ffffffffff6007ff 0 [kernel].vsyscall_1 in kallsyms as [kernel].6
ffffffffff600800-ffffffffffffffff 0 [kernel].vsyscall_2 in kallsyms as [kernel].8
Maps only in kallsyms:
ffffffffff600130-ffffffffff6003ff 0 [kernel].4
---- end ----
vmlinux symtab matches kallsyms: Ok
[acme@doppio linux-2.6-tip]$
In the above case we only know the name of the non contiguous kernel ranges in
the address space when reading the symbol information from the ELF symtab in
vmlinux.
The /proc/kallsyms file lack this, we only notice they are separate because
there are modules after the kernel and after that more kernel functions, so we
need to have a module rbtree backed by the module .ko path to get symtabs in
the vmlinux case.
The tool uses it to match by address to emit appropriate warning, but don't
considers this fatal.
The .init.text and .exit.text ines, of course, aren't in kallsyms, so I left
these cases just as extra info in verbose mode.
The end of the sections also aren't in kallsyms, so we the symbols layer does
another pass and sets the end addresses as the next map start minus one, which
sometimes pads, causing harmless mismatches.
But at least the symbols match, tested it by copying /proc/kallsyms to
/tmp/kallsyms and doing changes to see if they were detected.
This first test also should serve as a first stab at documenting the
symbol library by providing a self contained example that exercises it
together with comments about what is being done.
More tests to check if actions done on a monitored app, like doing mmaps, etc,
makes the kernel generate the expected events should be added next.
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that "make -C tools/perf O=/tmp/some/path" works again.
Problem introduced in:
cd932c5 "perf: Move arch specific code into separate arch director"
Cc: Ian Munsie <imunsie@au.ibm.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Those functions operated on members now grouped in 'struct machine', so
move those methods to this new class.
The changes made to 'perf probe' shows that using this abstraction
inserting probes on guests almost got supported for free.
Cc: Avi Kivity <avi@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
struct kernel_info and kerninfo__ are too vague, what they really
describe are machines, virtual ones or hosts.
There are more changes to introduce helpers to shorten function calls
and to make more clear what is really being done, but I left that for
subsequent patches.
Cc: Avi Kivity <avi@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>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use the new generic sample events reordering from perf trace.
Before that, the displayed traces were ordered as they were
in the input as recorded by perf record (not time ordered).
This makes eventually perf trace displaying the events as beeing
time ordered.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
The sample events recorded by perf record are not time ordered
because we have one buffer per cpu for each event (even demultiplexed
per task/per cpu for task bound events). But when we read trace events
we want them to be ordered by time because many state machines are
involved.
There are currently two ways perf tools deal with that:
- use -M to multiplex every buffers (perf sched, perf kmem)
But this creates a lot of contention in SMP machines on
record time.
- use a post-processing time reordering (perf timechart, perf lock)
The reordering used by timechart is simple but doesn't scale well
with huge flow of events, in terms of performance and memory use
(unusable with perf lock for example).
Perf lock has its own samples reordering that flushes its memory
use in a regular basis and that uses a sorting based on the
previous event queued (a new event to be queued is close to the
previous one most of the time).
This patch proposes to export perf lock's samples reordering facility
to the session layer that reads the events. So if a tool wants to
get ordered sample events, it needs to set its
struct perf_event_ops::ordered_samples to true and that's it.
This prepares tracing based perf tools to get rid of the need to
use buffers multiplexing (-M) or to implement their own
reordering.
Also lower the flush period to 2 as it's sufficient already.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
The parse_single_tracepoint_event() was setting some attributes
before it validated the event was indeed a tracepoint event. This
caused problems with other initialization routines like in the
builtin-top.c module whereby sample_period is not set if not 0.
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <4bcf232b.698fd80a.6fbe.ffffb737@mx.google.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Previous state machine of perf lock was really broken.
This patch improves it a little.
This patch prepares the list of state machine that represents
lock sequences for each threads.
These state machines can be one of these sequences:
1) acquire -> acquired -> release
2) acquire -> contended -> acquired -> release
3) acquire (w/ try) -> release
4) acquire (w/ read) -> release
The case of 4) is a little special.
Double acquire of read lock is allowed, so the state machine
counts read lock number, and permits double acquire and release.
But, things are not so simple. Something in my model is still wrong.
I counted the number of lock instances with bad sequence,
and ratio is like this (case of tracing whoami): bad:233, total:2279
version 2:
* threads are now identified with tid, not pid
* prepared SEQ_STATE_READ_ACQUIRED for read lock.
* bunch of struct lock_seq_stat is now linked list
* debug information enhanced (this have to be removed someday)
e.g.
| === output for debug===
|
| bad:233, total:2279
| bad rate:0.000000
| histogram of events caused bad sequence
| acquire: 165
| acquired: 0
| contended: 0
| release: 68
Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1271852634-9351-1-git-send-email-mitake@dcl.info.waseda.ac.jp>
[rename SEQ_STATE_UNINITED to SEQ_STATE_UNINITIALIZED]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
