For data type profiling, it removed non-instruction lines from the list
of annotation lines. It was to simplify the implementation dealing with
instructions like to calculate the PC-relative address and to search the
shortest path to the target instruction or basic block.
But it means that it removes all the comments and debug information in
the annotate output like source file name and line numbers. To support
both code annotation and data type annotation, it'd be better to keep
the non-instruction lines as well.
So this change is to skip those lines during the data type profiling
and to display them in the normal perf annotate output.
No function changes intended (other than having more lines).
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240405211800.1412920-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The symbol__annotate2() initializes some data structures needed by TUI.
It has a logic to prevent calling it multiple times by checking if it
has the annotated source. But data type profiling uses a different
code (symbol__annotate) to allocate the annotated lines in advance.
So TUI missed to call symbol__annotate2() when it shows the annotation
browser.
Make symbol__annotate() reentrant and handle that situation properly.
This fixes a crash in the annotation browser started by perf report in
TUI like below.
$ perf report -s type,sym --tui
# and press 'a' key and then move down
Fixes: 81e57deec3 ("perf report: Support data type profiling")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240405211800.1412920-2-namhyung@kernel.org
It should pass a proper address (i.e. suitable for objdump or addr2line)
to get_srcline() in order to work correctly. It used to pass an address
with map__rip_2objdump() as the second argument but later it's changed
to use notes->start. It's ok in normal cases but it can be changed when
annotate_opts.full_addr is set. So let's convert the address directly
instead of using the notes->start.
Also the last argument is an IP to print symbol offset if requested. So
it should pass symbol-relative address.
Fixes: 7d18a824b5 ("perf annotate: Toggle full address <-> offset display")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240404175716.1225482-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In some older distros the build is failing due to
-Werror=maybe-uninitialized, in this case we know that this isn't the
case because 'arch' gets initialized by evsel__get_arch(), so make sure
it is initialized to NULL before returning from evsel__get_arch(), as
suggested by Ian Rogers.
E.g.:
32 17.12 opensuse:15.5 : FAIL gcc version 7.5.0 (SUSE Linux)
util/annotate.c: In function 'hist_entry__get_data_type':
util/annotate.c:2269:15: error: 'arch' may be used uninitialized in this function [-Werror=maybe-uninitialized]
struct arch *arch;
^~~~
cc1: all warnings being treated as errors
43 7.30 ubuntu:18.04-x-powerpc64el : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
util/annotate.c: In function 'hist_entry__get_data_type':
util/annotate.c:2351:36: error: 'arch' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if (map__dso(ms->map)->kernel && arch__is(arch, "x86") &&
^~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Suggested-by: Ian Rogers <irogers@google.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/CAP-5=fUqtjxAsmdGrnkjhUTLHs-JvV10TtxyocpYDJK_+LYTiQ@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The util/annotate.c code has both disassembly and sample annotation
related codes. Factor out the disasm part so that it can be handled
more easily.
No functional changes intended.
Committer notes:
Add missing include env.h, util.h, bpf-event.h and bpf-util.h to
disasm.c, to fix things like:
util/disasm.c: In function ‘symbol__disassemble_bpf’:
util/disasm.c:1203:9: error: implicit declaration of function ‘perf_exe’ [-Werror=implicit-function-declaration]
1203 | perf_exe(tpath, sizeof(tpath));
| ^~~~~~~~
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240329215812.537846-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
On x86, the kernel gets the current task using the current macro like
below:
#define current get_current()
static __always_inline struct task_struct *get_current(void)
{
return this_cpu_read_stable(pcpu_hot.current_task);
}
So it returns the current_task field of struct pcpu_hot which is the
first member. On my build, it's located at 0x32940.
$ nm vmlinux | grep pcpu_hot
0000000000032940 D pcpu_hot
And the current macro generates the instructions like below:
mov %gs:0x32940, %rcx
So the %gs segment register points to the beginning of the per-cpu
region of this cpu and it points the variable with a constant.
Let's update the instruction location info to have a segment register
and handle %gs in kernel to look up a global variable. Pretend it as
a global variable by changing the register number to DWARF_REG_PC.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240319055115.4063940-18-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now symbol histogram uses an array to save per-offset sample counts.
But it wastes a lot of memory if the symbol has a few samples only.
Add a hashmap to save values only for actual samples.
For now, it has duplicate histogram (one in the existing array and
another in the new hash map). Once it can convert to use the hash
in all places, we can get rid of the array later.
Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240304230815.1440583-2-namhyung@kernel.org
Global variables are accessed using PC-relative address so it needs to
be handled separately. The PC-rel addressing is detected by using
DWARF_REG_PC. On x86, %rip register would be used.
The address can be calculated using the ip and offset in the
instruction. But it should start from the next instruction so add
calculate_pcrel_addr() to do it properly.
But global variables defined in a different file would only have a
declaration which doesn't include a location list. So it first tries
to get the type info using the address, and then looks up the variable
declarations using name. The name of global variables should be get
from the symbol table. The declaration would have the type info.
So extend find_var_type() to take both address and name for global
variables.
The stat is now looks like:
Annotate data type stats:
total 294, ok 153 (52.0%), bad 141 (48.0%)
-----------------------------------------------------------
30 : no_sym
32 : no_mem_ops
61 : no_var
10 : no_typeinfo
8 : bad_offset
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240117062657.985479-7-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
A typical function prologue and epilogue include multiple stack
operations to save and restore the current value of registers.
On x86, it looks like below:
push r15
push r14
push r13
push r12
...
pop r12
pop r13
pop r14
pop r15
ret
As these all touches the stack memory region, chances are high that they
appear in a memory profile data. But these are not used for any real
purpose yet so it'd return no types.
One of my profile type shows that non neglible portion of data came from
the stack operations. It also seems GCC generates more stack operations
than clang.
Annotate Instruction stats
total 264, ok 169 (64.0%), bad 95 (36.0%)
Name : Good Bad
-----------------------------------------------------------
movq : 49 27
movl : 24 9
popq : 0 19 <-- here
cmpl : 17 2
addq : 14 1
cmpq : 12 2
cmpxchgl : 3 7
Instead of dealing them as unknown, let's create a seperate pseudo type
to represent those stack operations separately.
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240117062657.985479-5-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
On x86, instructions for array access often looks like below.
mov 0x1234(%rax,%rbx,8), %rcx
Usually the first register holds the type information and the second one
has the index. And the current code only looks up a variable for the
first register. But it's possible to be in the other way around so it
needs to check the second register if the first one failed.
The stat changed like this.
Annotate data type stats:
total 294, ok 148 (50.3%), bad 146 (49.7%)
-----------------------------------------------------------
30 : no_sym
32 : no_mem_ops
66 : no_var
10 : no_typeinfo
8 : bad_offset
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240117062657.985479-4-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
When a sample was come from a conditional branch without a memory
operand, it could be due to a macro fusion with a previous instruction.
So it needs to check the memory operand in the previous one.
This improves the stat like below:
Annotate data type stats:
total 294, ok 147 (50.0%), bad 147 (50.0%)
-----------------------------------------------------------
30 : no_sym
32 : no_mem_ops
71 : no_var
6 : no_typeinfo
8 : bad_offset
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240117062657.985479-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
For the performance reason, I prefer llvm-objdump over GNU's. But I
found that llvm-objdump puts x86 lock prefix in a separate line like
below.
ffffffff81000695: f0 lock
ffffffff81000696: ff 83 54 0b 00 00 incl 2900(%rbx)
This should be parsed properly, but I just changed to find the insn
with next offset for now.
This improves the statistics as it can process more instructions.
Annotate data type stats:
total 294, ok 144 (49.0%), bad 150 (51.0%)
-----------------------------------------------------------
30 : no_sym
35 : no_mem_ops
71 : no_var
6 : no_typeinfo
8 : bad_offset
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240117062657.985479-2-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
This is for a debugging purpose. It'd be useful to see per-instrucion
level success/failure stats.
$ perf annotate --data-type --insn-stat
Annotate Instruction stats
total 264, ok 143 (54.2%), bad 121 (45.8%)
Name : Good Bad
-----------------------------------------------------------
movq : 45 31
movl : 22 11
popq : 0 19
cmpl : 16 3
addq : 8 7
cmpq : 11 3
cmpxchgl : 3 7
cmpxchgq : 8 0
incl : 3 3
movzbl : 4 2
incq : 4 2
decl : 6 0
...
Committer notes:
So these are about being able to find the type for accesses from these
instructions, we should improve the naming, but it is for debugging, we
can improve this later:
@@ -3726,6 +3759,10 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
continue;
mem_type = find_data_type(ms, ip, op_loc->reg, op_loc->offset);
+ if (mem_type)
+ istat->good++;
+ else
+ istat->bad++;
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-18-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Support data type annotation with new --data-type option. It internally
uses type sort key to collect sample histogram for the type and display
every members like below.
$ perf annotate --data-type
...
Annotate type: 'struct cfs_rq' in [kernel.kallsyms] (13 samples):
============================================================================
samples offset size field
13 0 640 struct cfs_rq {
2 0 16 struct load_weight load {
2 0 8 unsigned long weight;
0 8 4 u32 inv_weight;
};
0 16 8 unsigned long runnable_weight;
0 24 4 unsigned int nr_running;
1 28 4 unsigned int h_nr_running;
...
For simplicity it prints the number of samples per field for now.
But it should be easy to show the overhead percentage instead.
The number at the outer struct is a sum of the numbers of the inner
members. For example, struct cfs_rq got total 13 samples, and 2 came
from the load (struct load_weight) and 1 from h_nr_running. Similarly,
the struct load_weight got total 2 samples and they all came from the
weight field.
I've added two new flags in the symbol_conf for this. The
annotate_data_member is to get the members of the type. This is also
needed for perf report with typeoff sort key. The annotate_data_sample
is to update sample stats for each offset and used only in annotate.
Currently it only support stdio output mode, TUI support can be added
later.
Committer testing:
With the perf.data from the previous csets, a very simple, short
duration one:
# perf annotate --data-type
Annotate type: 'struct list_head' in [kernel.kallsyms] (1 samples):
============================================================================
samples offset size field
1 0 16 struct list_head {
0 0 8 struct list_head* next;
1 8 8 struct list_head* prev;
};
Annotate type: 'char' in [kernel.kallsyms] (1 samples):
============================================================================
samples offset size field
1 0 1 char ;
#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-15-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The typeoff sort key shows the data type name, offset and the name of
the field. This is useful to see which field in the struct is accessed
most frequently.
$ perf report -s type,typeoff --hierarchy --stdio
...
# Overhead Data Type / Data Type Offset
# ............ ............................
#
...
1.23% struct cfs_rq
0.19% struct cfs_rq +404 (throttle_count)
0.19% struct cfs_rq +0 (load.weight)
0.19% struct cfs_rq +336 (leaf_cfs_rq_list.next)
0.09% struct cfs_rq +272 (propagate)
0.09% struct cfs_rq +196 (removed.nr)
0.09% struct cfs_rq +80 (curr)
0.09% struct cfs_rq +544 (lt_b_children_throttled)
0.06% struct cfs_rq +320 (rq)
Committer testing:
Again with the perf.data from the previous csets:
# perf report --stdio -s type,typeoff
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 4 of event 'cpu_atom/mem-loads,ldlat=30/P'
# Event count (approx.): 7
#
# Overhead Data Type Data Type Offset
# ........ ......... ................
#
42.86% struct list_head struct list_head +8 (prev)
42.86% (unknown) (unknown) +0 (no field)
14.29% char char +0 (no field)
#
# (Tip: To see callchains in a more compact form: perf report -g folded)
#
# perf report --stdio -s dso,type,typeoff
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 4 of event 'cpu_atom/mem-loads,ldlat=30/P'
# Event count (approx.): 7
#
# Overhead Shared Object Data Type Data Type Offset
# ........ .................... ......... ................
#
42.86% [kernel.kallsyms] struct list_head struct list_head +8 (prev)
28.57% libc.so.6 (unknown) (unknown) +0 (no field)
14.29% [kernel.kallsyms] char char +0 (no field)
14.29% ld-linux-x86-64.so.2 (unknown) (unknown) +0 (no field)
#
# (Tip: If you have debuginfo enabled, try: perf report -s sym,srcline)
#
#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-13-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
