Prior to this change a string was used which could cause issues with
an unrecognized disassembler in symbol__disassembler. Change to
initializing an array of perf_disassembler enum values. If a value
already exists then adding it a second time is ignored to avoid array
out of bounds problems present in the previous code, it also allows a
statically sized array and removes memory allocation needs. Errors in
the disassembler string are reported when the config is parsed during
perf annotate or perf top start up. If the array is uninitialized
after processing the config file the default llvm, capstone then
objdump values are added but without a need to parse a string.
Fixes: a6e8a58de6 ("perf disasm: Allow configuring what disassemblers to use")
Closes: https://lore.kernel.org/lkml/CAP-5=fUdfCyxmEiTpzS2uumUp3-SyQOseX2xZo81-dQtWXj6vA@mail.gmail.com/
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250124043856.1177264-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The perf tools annotation code used for a long time parsing the output
of binutils's objdump (or its reimplementations, like llvm's) to then
parse and augment it with samples, allow navigation, etc.
More recently disassemblers from the capstone and llvm (libraries, not
parsing the output of tools using those libraries to mimic binutils's
objdump output) were introduced.
So when all those methods are available, there is a static preference
for a series of attempts of disassembling a binary, with the 'llvm,
capstone, objdump' sequence being hard coded.
This patch allows users to change that sequence, specifying via a 'perf
config' 'annotate.disassemblers' entry which and in what order
disassemblers should be attempted.
As alluded to in the comments in the source code of this series, this
flexibility is useful for users and developers alike, elliminating the
requirement to rebuild the tool with some specific set of libraries to
see how the output of disassembling would be for one of these methods.
root@x1:~# rm -f ~/.perfconfig
root@x1:~# perf annotate -v --stdio2 update_load_avg
<SNIP>
symbol__disassemble:
filename=/usr/lib/debug/lib/modules/6.11.4-201.fc40.x86_64/vmlinux,
sym=update_load_avg, start=0xffffffffb6148fe0, en>
annotating [0x6ff7170]
/usr/lib/debug/lib/modules/6.11.4-201.fc40.x86_64/vmlinux :
[0x7407ca0] update_load_avg
Disassembled with llvm
annotate.disassemblers=llvm,capstone,objdump
Samples: 66 of event 'cpu_atom/cycles/P', 10000 Hz,
Event count (approx.): 5185444, [percent: local period]
update_load_avg()
/usr/lib/debug/lib/modules/6.11.4-201.fc40.x86_64/vmlinux
Percent 0xffffffff81148fe0 <update_load_avg>:
1.61 pushq %r15
pushq %r14
1.00 pushq %r13
movl %edx,%r13d
1.90 pushq %r12
pushq %rbp
movq %rsi,%rbp
pushq %rbx
movq %rdi,%rbx
subq $0x18,%rsp
15.14 movl 0x1a4(%rdi),%eax
root@x1:~# perf config annotate.disassemblers=capstone
root@x1:~# cat ~/.perfconfig
# this file is auto-generated.
[annotate]
disassemblers = capstone
root@x1:~#
root@x1:~# perf annotate -v --stdio2 update_load_avg
<SNIP>
Disassembled with capstone
annotate.disassemblers=capstone
Samples: 66 of event 'cpu_atom/cycles/P', 10000 Hz,
Event count (approx.): 5185444, [percent: local period]
update_load_avg()
/usr/lib/debug/lib/modules/6.11.4-201.fc40.x86_64/vmlinux
Percent 0xffffffff81148fe0 <update_load_avg>:
1.61 pushq %r15
pushq %r14
1.00 pushq %r13
movl %edx,%r13d
1.90 pushq %r12
pushq %rbp
movq %rsi,%rbp
pushq %rbx
movq %rdi,%rbx
subq $0x18,%rsp
15.14 movl 0x1a4(%rdi),%eax
root@x1:~# perf config annotate.disassemblers=objdump,capstone
root@x1:~# perf config annotate.disassemblers
annotate.disassemblers=objdump,capstone
root@x1:~# cat ~/.perfconfig
# this file is auto-generated.
[annotate]
disassemblers = objdump,capstone
root@x1:~# perf annotate -v --stdio2 update_load_avg
Executing: objdump --start-address=0xffffffff81148fe0 \
--stop-address=0xffffffff811497aa \
-d --no-show-raw-insn -S -C "$1"
Disassembled with objdump
annotate.disassemblers=objdump,capstone
Samples: 66 of event 'cpu_atom/cycles/P', 10000 Hz,
Event count (approx.): 5185444, [percent: local period]
update_load_avg()
/usr/lib/debug/lib/modules/6.11.4-201.fc40.x86_64/vmlinux
Percent
Disassembly of section .text:
ffffffff81148fe0 <update_load_avg>:
#define DO_ATTACH 0x4
ffffffff81148fe0 <update_load_avg>:
#define DO_ATTACH 0x4
#define DO_DETACH 0x8
/* Update task and its cfs_rq load average */
static inline void update_load_avg(struct cfs_rq *cfs_rq,
struct sched_entity *se,
int flags)
{
1.61 push %r15
push %r14
1.00 push %r13
mov %edx,%r13d
1.90 push %r12
push %rbp
mov %rsi,%rbp
push %rbx
mov %rdi,%rbx
sub $0x18,%rsp
}
/* rq->task_clock normalized against any time
this cfs_rq has spent throttled */
static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
{
if (unlikely(cfs_rq->throttle_count))
15.14 mov 0x1a4(%rdi),%eax
root@x1:~#
After adding a way to select the disassembler from the command line a
'perf test' comparing the output of the various diassemblers should be
introduced, to test these codebases.
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steinar H. Gunderson <sesse@google.com>
Link: https://lore.kernel.org/r/20241111151734.1018476-4-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
No event is printed in the "Branch Counter" column on hybrid machines.
For example,
$ perf record -e "{cpu_core/branch-instructions/pp,cpu_core/branches/}:S" -j any,counter
$ perf report --total-cycles
# Branch counter abbr list:
# cpu_core/branch-instructions/pp = A
# cpu_core/branches/ = B
# '-' No event occurs
# '+' Event occurrences may be lost due to branch counter saturated
#
# Sampled Cycles% Sampled Cycles Avg Cycles% Avg Cycles Branch Counter
# ............... .............. ........... .......... ..............
44.54% 727.1K 0.00% 1 |+ |+ |
36.31% 592.7K 0.00% 2 |+ |+ |
17.83% 291.1K 0.00% 1 |+ |+ |
The branch counter information (br_cntr_width and br_cntr_nr) in the
perf_env is retrieved from the CPU_PMU_CAPS. However, the CPU_PMU_CAPS
is not available on hybrid machines. Without the width information, the
number of occurrences of an event cannot be calculated.
For a hybrid machine, the caps information should be retrieved from the
PMU_CAPS, and stored in the perf_env->pmu_caps.
Add a perf_env__find_br_cntr_info() to return the correct branch counter
information from the corresponding fields.
Committer notes:
While testing I couldn't s ee those "Branch counter" columns enabled by
pressing 'B' on the TUI, after reporting it to the list Kan explained
the situation:
<quote Kan Liang>
For a hybrid client, the "Branch Counter" feature is only supported
starting from the just released Lunar Lake. Perf falls back to only
"ANY" on your Raptor Lake.
The "The branch counter is not available" message is expected.
Here is the 'perf evlist' result from my Lunar Lake machine,
# perf evlist -v
cpu_core/branch-instructions/pp: type: 4 (cpu_core), size: 136, config: 0xc4 (branch-instructions), { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|READ|PERIOD|BRANCH_STACK|IDENTIFIER, read_format: ID|GROUP|LOST, disabled: 1, freq: 1, enable_on_exec: 1, precise_ip: 2, sample_id_all: 1, exclude_guest: 1, branch_sample_type: ANY|COUNTERS
#
</quote>
Fixes: 6f9d8d1de2 ("perf script: Add branch counters")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240909184201.553519-1-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When annotating a basic block, it's useful to display the occurrences
of other events in the block.
The branch counter feature is only available for newer Intel platforms.
So a dedicated option to display the branch counters is not introduced.
Reuse the existing --total-cycles option, which triggers the annotation
of a basic block and displays the cycle-related annotation.
When the branch counters information is available, the branch counters
are automatically appended after all the cycle-related annotation.
Accounting the branch counters as well when accounting the cycles in
hist__account_cycles().
In 'struct annotated_branch', introduce a br_cntr array to save the
accumulation of each branch counter.
In a sample, all the branch counters for a branch are saved in a u64
space.
Because the saturation of a branch counter is small, e.g., for Intel
Sierra Forest, the saturation is only 3.
Add ANNOTATION__BR_CNTR_SATURATED_FLAG to indicate if a branch counter
once saturated. That can be used to indicate a potential event lost
because of the saturation.
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-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: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240813160208.2493643-5-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In find_data_type(), it creates and deletes a debug info whenver it
tries to find data type for a sample. This is inefficient and it most
likely accesses the same binary again and again.
Let's add a single entry cache the debug info structure for the last DSO.
Depending on sample data, it usually gives me 2~3x (and sometimes more)
speed ups.
Note that this will introduce a little difference in the output due to
the order of checking stack operations. It used to check the stack ops
before checking the availability of debug info but I moved it after the
symbol check. So it'll report stack operations in DSOs without debug
info as unknown. But I think it's ok and better to have the checking
near the caching logic.
Committer testing:
root@x1:~# perf mem record -a sleep 5s
root@x1:~# perf evlist
cpu_atom/mem-loads,ldlat=30/P
cpu_atom/mem-stores/P
dummy:u
root@x1:~# diff -u before after
--- before 2024-08-08 09:33:53.880780784 -0300
+++ after 2024-08-08 09:35:13.917325041 -0300
@@ -81,8 +81,8 @@
# Overhead Data Type
# ........ .........
#
- 55.43% (unknown)
- 11.61% (stack operation)
+ 55.56% (unknown)
+ 11.48% (stack operation)
4.93% struct pcpu_hot
3.26% unsigned int
2.48% struct
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: Athira Rajeev <atrajeev@linux.vnet.ibm.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: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240805234648.1453689-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since the "ins.name" is not set while using raw instruction,
'perf annotate' with insn-stat gives wrong data:
Result from "./perf annotate --data-type --insn-stat":
Annotate Instruction stats
total 615, ok 419 (68.1%), bad 196 (31.9%)
Name : Good Bad
-----------------------------------------------------------
: 419 196
This patch sets "dl->ins.name" in arch specific function
"check_ppc_insn" while initialising "struct disasm_line".
Also update "ins_find" function to pass "struct disasm_line" as a
parameter so as to set its name field in arch specific call.
With the patch changes:
Annotate Instruction stats
total 609, ok 446 (73.2%), bad 163 (26.8%)
Name/opcode : Good Bad
-----------------------------------------------------------
58 : 323 80
32 : 49 43
34 : 33 11
OP_31_XOP_LDX : 8 20
40 : 23 0
OP_31_XOP_LWARX : 5 1
OP_31_XOP_LWZX : 2 3
OP_31_XOP_LDARX : 3 0
33 : 0 2
OP_31_XOP_LBZX : 0 1
OP_31_XOP_LWAX : 0 1
OP_31_XOP_LHZX : 0 1
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Kajol Jain <kjain@linux.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Akanksha J N <akanksha@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Link: https://lore.kernel.org/lkml/20240718084358.72242-16-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
