| Age | Commit message (Collapse) | Author |
|---|
|
The struct zone is embedded in struct pglist_data which can be allocated
for each NUMA node early in the boot process. As it's not a slab object
nor a global lock, this was not symbolized.
Since the zone->lock is often contended, it'd be nice if we can
symbolize it. On NUMA systems, node_data array will have pointers for
struct pglist_data. By following the pointer, it can calculate the
address of each zone and its lock using BTF. On UMA, it can just use
contig_page_data and its zones.
The following example shows the zone lock contention at the end.
$ sudo ./perf lock con -abl -E 5 -- ./perf bench sched messaging
# Running 'sched/messaging' benchmark:
# 20 sender and receiver processes per group
# 10 groups == 400 processes run
Total time: 0.038 [sec]
contended total wait max wait avg wait address symbol
5167 18.17 ms 10.27 us 3.52 us ffff953340052d00 &kmem_cache_node (spinlock)
38 11.75 ms 465.49 us 309.13 us ffff95334060c480 &sock_inode_cache (spinlock)
3916 10.13 ms 10.43 us 2.59 us ffff953342aecb40 &kmem_cache_node (spinlock)
2963 10.02 ms 13.75 us 3.38 us ffff9533d2344098 &kmalloc-rnd-08-2k (spinlock)
216 5.05 ms 99.49 us 23.39 us ffff9542bf7d65d0 zone_lock (spinlock)
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: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: bpf@vger.kernel.org
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20250401063055.7431-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
Recently the kernel got the kmem_cache iterator to traverse metadata of
slab objects. This can be used to symbolize dynamic locks in a slab.
The new slab_caches hash map will have the pointer of the kmem_cache as
a key and save the name and a id. The id will be saved in the flags
part of the lock.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Chun-Tse Shao <ctshao@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20241220060009.507297-3-namhyung@kernel.org
[ Added change from Namhyung addressing review from Alexei: ]
Link: https://lore.kernel.org/r/Z2dVdH3o5iF-KrWj@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
The new cgroup filter can take either of '==' or '!=' operator and a
pathname for the target cgroup.
$ perf record -a --all-cgroups -e cycles --filter 'cgroup == /abc/def' -- sleep 1
Users should have --all-cgroups option in the command line to enable
cgroup filtering. Technically it doesn't need to have the option as
it can get the current task's cgroup info directly from BPF. But I want
to follow the convention for the other sample info.
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: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240826221045.1202305-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
So far it used tgid as a key to get the filter expressions in the
pinned filters map for regular users but it won't work well if the has
more than one filters at the same time. Let's add the event id to the
key of the filter hash map so that it can identify the right filter
expression in the BPF program.
As the event can be inherited to child tasks, it should use the primary
id which belongs to the parent (original) event. Since evsel opens the
event for multiple CPUs and tasks, it needs to maintain a separate hash
map for the event id.
In the user space, it keeps a list for the multiple evsel and release
the entries in the both hash map when it closes the event.
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: KP Singh <kpsingh@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240820154504.128923-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
The bpf_get_stackid() helper returns a signed type to check whether it
failed to get a stacktrace or not. But it saved the result in u32 and
checked if the value is negative.
376 if (needs_callstack) {
377 pelem->stack_id = bpf_get_stackid(ctx, &stacks,
378 BPF_F_FAST_STACK_CMP | stack_skip);
--> 379 if (pelem->stack_id < 0)
./tools/perf/util/bpf_skel/lock_contention.bpf.c:379 contention_begin()
warn: unsigned 'pelem->stack_id' is never less than zero.
Let's change the type to s32 instead.
Fixes: 6d499a6b3d90277d ("perf lock: Print the number of lost entries for BPF")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
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/20240812172533.2015291-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
If we instead decide to generate vmlinux.h from BTF info, it will be
there:
$ pahole timespec64
struct timespec64 {
time64_t tv_sec; /* 0 8 */
long int tv_nsec; /* 8 8 */
/* size: 16, cachelines: 1, members: 2 */
/* last cacheline: 16 bytes */
};
$
pahole manages to find it from /sys/kernel/btf/vmlinux, that is
generated from the kernel types.
With this linux/bpf.h doesn't need to be included, as its already in the
minimalistic tools/perf/util/bpf_skel/vmlinux/vmlinux.h file or what we
need comes when generating a vmlinux.h file from BTF info, i.e. when
using GEN_VMLINUX_H=1, as noticed by Namyung in a build break before
removing linux/bpf.h.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/Zc_fp6CgDClPhS_O@x1
|
|
The recent change made it possible to generate vmlinux.h from BTF and
to ignore the file. But we also have a minimal vmlinux.h that will be
used by default. It should not be ignored by GIT.
Fixes: b7a2d774c9c5 ("perf build: Add ability to build with a generated vmlinux.h")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310110451.rvdUZJEY-lkp@intel.com/
Cc: oe-kbuild-all@lists.linux.dev
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
|
|
struct rq is defined in vmlinux.h when the vmlinux.h is generated,
this causes a redefinition failure if it is declared in
lock_contention.bpf.c. Move the definition to vmlinux.h for
consistency with the generated version.
Fixes: 760ebc45746b ("perf lock contention: Add empty 'struct rq' to satisfy libbpf 'runqueue' type verification")
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230623041405.4039475-3-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
|
|
Commit a887466562b4 ("perf bpf skels: Stop using vmlinux.h generated
from BTF, use subset of used structs + CO-RE") made it so that
vmlinux.h was uncondtionally included from
tools/perf/util/vmlinux.h. This change reverts part of that change (so
that vmlinux.h is once again generated) and makes it so that the
vmlinux.h used at build time is selected from the VMLINUX_H
variable. By default the VMLINUX_H variable is set to the vmlinux.h
added in change a887466562b4, but if GEN_VMLINUX_H=1 is passed on the
build command line then the previous generation behavior kicks in.
The build with GEN_VMLINUX_H=1 currently fails with:
util/bpf_skel/lock_contention.bpf.c:419:8: error: redefinition of 'rq'
struct rq {};
^
/tmp/perf/util/bpf_skel/.tmp/../vmlinux.h:45630:8: note: previous definition is here
struct rq {
^
1 error generated.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230623041405.4039475-2-irogers@google.com
[ Format the error message and add a comment for GEN_VMLINUX_H ]
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
|
