First try to read the e_machine from the dsos associated with the
thread's maps. If live use the executable from /proc/pid/exe and read
the e_machine from the ELF header. On failure use EM_HOST. Change
builtin-trace syscall functions to pass e_machine from the thread
rather than EM_HOST, so that in later patches when syscalltbl can use
the e_machine the system calls are specific to the architecture.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Link: https://lore.kernel.org/r/20250319050741.269828-8-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The 'struct callchain_cursor_node' has a 'struct map_symbol' whose maps
and map members are reference counted. Ensure these values use a _get
routine to increment the reference counts and use map_symbol__exit() to
release the reference counts.
Do similar for 'struct thread's prev_lbr_cursor, but save the size of
the prev_lbr_cursor array so that it may be iterated.
Ensure that when stitch_nodes are placed on the free list the
map_symbols are exited.
Fix resolve_lbr_callchain_sample() by replacing list_replace_init() to
list_splice_init(), so the whole list is moved and nodes aren't leaked.
A reproduction of the memory leaks is possible with a leak sanitizer
build in the perf report command of:
```
$ perf record -e cycles --call-graph lbr perf test -w thloop
$ perf report --stitch-lbr
```
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Fixes: ff165628d7 ("perf callchain: Stitch LBR call stack")
Signed-off-by: Ian Rogers <irogers@google.com>
[ Basic tests after applying the patch, repeating the example above ]
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anne Macedo <retpolanne@posteo.net>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240808054644.1286065-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Move thread_rb_node into the machine.c file. This hides the
implementation of threads from the rest of the code allowing for it to
be refactored.
Locking discipline is tightened up in this change. As the lock is now
encapsulated in threads, the findnew function requires holding it (as
it already did in machine). Rather than do conditionals with locks
based on whether the thread should be created (which could potentially
be error prone with a read lock match with a write unlock), have a
separate threads__find that won't create the thread and only holds the
read lock. This effectively duplicates the findnew logic, with the
existing findnew logic only operating under a write lock assuming
creation is necessary as a previous find failed. The creation may
still fail with the write lock due to another thread. The duplication
is removed in a later next patch that delegates the implementation to
hashtable.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240301053646.1449657-5-irogers@google.com
Currently, the instructions of samples are shown as raw hex strings
which are hard to read. x86 has a special option '--xed' to disassemble
the hex string via intel XED tool.
Here we use capstone as our disassembler engine to give more friendly
instructions. We select libcapstone because capstone can provide more
insn details. Perf will fallback to raw instructions if libcapstone is
not available.
The advantages compared to XED tool:
* Support arm, arm64, x86-32, x86_64 (more could be supported),
xed only for x86_64.
* Immediate address operands are shown as symbol+offs.
Signed-off-by: Changbin Du <changbin.du@huawei.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: changbin.du@gmail.com
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240217074046.4100789-3-changbin.du@huawei.com
Its a thread method, so move it to thread.h, this way some places that
were using event.h just to get this prototype may stop doing so and
speed up building and disentanble the header dependency graph.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In LBR call stack mode, the depth of reconstructed LBR call stack limits
to the number of LBR registers.
For example, on skylake, the depth of reconstructed LBR call stack is
always <= 32.
# To display the perf.data header info, please use
# --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 6K of event 'cycles'
# Event count (approx.): 6487119731
#
# Children Self Command Shared Object Symbol
# ........ ........ ............... ..................
# ................................
99.97% 99.97% tchain_edit tchain_edit [.] f43
|
--99.64%--f11
f12
f13
f14
f15
f16
f17
f18
f19
f20
f21
f22
f23
f24
f25
f26
f27
f28
f29
f30
f31
f32
f33
f34
f35
f36
f37
f38
f39
f40
f41
f42
f43
For a call stack which is deeper than LBR limit, HW will overwrite the
LBR register with oldest branch. Only partial call stacks can be
reconstructed.
However, the overwritten LBRs may still be retrieved from previous
sample. At that moment, HW hasn't overwritten the LBR registers yet.
Perf tools can stitch those overwritten LBRs on current call stacks to
get a more complete call stack.
To determine if LBRs can be stitched, perf tools need to compare current
sample with previous sample.
- They should have identical LBR records (Same from, to and flags
values, and the same physical index of LBR registers).
- The searching starts from the base-of-stack of current sample.
Once perf determines to stitch the previous LBRs, the corresponding LBR
cursor nodes will be copied to 'lists'. The 'lists' is to track the LBR
cursor nodes which are going to be stitched.
When the stitching is over, the nodes will not be freed immediately.
They will be moved to 'free_lists'. Next stitching may reuse the space.
Both 'lists' and 'free_lists' will be freed when all samples are
processed.
Committer notes:
Fix the intel-pt.c initialization of the union with 'struct
branch_flags', that breaks the build with its unnamed union on older gcc
versions.
Uninline thread__free_stitch_list(), as it grew big and started dragging
includes to thread.h, so move it to thread.c where what it needs in
terms of headers are already there.
This fixes the build in several systems such as debian:experimental when
cross building to the MIPS32 architecture, i.e. in the other cases what
was needed was being included by sheer luck.
In file included from builtin-sched.c:11:
util/thread.h: In function 'thread__free_stitch_list':
util/thread.h:169:3: error: implicit declaration of function 'free' [-Werror=implicit-function-declaration]
169 | free(pos);
| ^~~~
util/thread.h:169:3: error: incompatible implicit declaration of built-in function 'free' [-Werror]
util/thread.h:19:1: note: include '<stdlib.h>' or provide a declaration of 'free'
18 | #include "callchain.h"
+++ |+#include <stdlib.h>
19 |
util/thread.h:174:3: error: incompatible implicit declaration of built-in function 'free' [-Werror]
174 | free(pos);
| ^~~~
util/thread.h:174:3: note: include '<stdlib.h>' or provide a declaration of 'free'
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-13-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And pick the shortest name: 'struct maps'.
The split existed because we used to have two groups of maps, one for
functions and one for variables, but that only complicated things,
sometimes we needed to figure out what was at some address and then had
to first try it on the functions group and if that failed, fall back to
the variables one.
That split is long gone, so for quite a while we had only one struct
maps per struct map_groups, simplify things by combining those structs.
First patch is the minimum needed to merge both, follow up patches will
rename 'thread->mg' to 'thread->maps', etc.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-hom6639ro7020o708trhxh59@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Commit e5adfc3e7e ("perf map: Synthesize maps only for thread group
leader") changed the recording side so that we no longer get mmap events
for threads other than the thread group leader (when synthesising these
events for threads which exist before perf is started).
When a file recorded after this change is loaded, the lack of mmap
records mean that unwinding is not set up for any other threads.
This can be seen in a simple record/report scenario:
perf record --call-graph=dwarf -t $TID
perf report
If $TID is a process ID then the report will show call graphs, but if
$TID is a secondary thread the output is as if --call-graph=none was
specified.
Following the rationale in that commit, move the libunwind fields into
struct map_groups and update the libunwind functions to take this
instead of the struct thread. This is only required for
unwind__finish_access which must now be called from map_groups__delete
and the others are changed for symmetry.
Note that unwind__get_entries keeps the thread argument since it is
required for symbol lookup and the libdw unwind provider uses the thread
ID.
Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: e5adfc3e7e ("perf map: Synthesize maps only for thread group leader")
Link: http://lkml.kernel.org/r/20190815100146.28842-2-john@metanate.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
