[PATCH 0/8] Copy hashmap to libapi, use in perf expr

[PATCH 0/8] Copy hashmap to libapi, use in perf expr

[Ian Rogers]

Perf's expr code currently builds an array of strings then removes
duplicates. The array is larger than necessary and has recently been
increased in size. When this was done it was commented that a hashmap
would be preferable.

libbpf has a hashmap but libbpf isn't currently required to build
perf. To satisfy various concerns this change copies libbpf's hashmap
into libapi, it then adds a check in perf that the two are in sync.

Andrii's patch to hashmap from bpf-next is brought into this set to
fix issues with hashmap__clear.

Three minor changes to libbpf's hashmap are made that remove an unused
dependency, fix a compiler warning and make sure the hashmap isn't
part of the symbols in a static build of libbpf (dsos are handled by
the existing version script).

Two perf test are also brought in as they need refactoring to account
for the expr API change and it is expected they will land aheadof
this.
https://lore.kernel.org/lkml/20200513062236.854-2-irogers@google.com/

Tested with 'perf test' and make -C tools/perf build-test.

The hashmap change was originally part of an RFC:
https://lore.kernel.org/lkml/20200508053629.210324-1-irogers@google.com/

Andrii Nakryiko (1):
  libbpf: Fix memory leak and possible double-free in hashmap__clear

Ian Rogers (7):
  libbpf hashmap: Remove unused #include
  libbpf hashmap: Fix signedness warnings
  libbpf hashmap: Localize static hashmap__* symbols
  tools lib/api: Copy libbpf hashmap to libapi
  perf test: Provide a subtest callback to ask for the reason for
    skipping a subtest
  perf test: Improve pmu event metric testing
  perf expr: Migrate expr ids table to a hashmap

 tools/lib/api/Build             |   1 +
 tools/lib/api/hashmap.c         | 238 ++++++++++++++++++++++++++++++++
 tools/lib/api/hashmap.h         | 177 ++++++++++++++++++++++++
 tools/lib/bpf/Makefile          |   2 +
 tools/lib/bpf/hashmap.c         |  10 +-
 tools/lib/bpf/hashmap.h         |   1 -
 tools/perf/check-headers.sh     |   4 +
 tools/perf/tests/builtin-test.c |  18 ++-
 tools/perf/tests/expr.c         |  40 +++---
 tools/perf/tests/pmu-events.c   | 169 ++++++++++++++++++++++-
 tools/perf/tests/tests.h        |   4 +
 tools/perf/util/expr.c          | 129 +++++++++--------
 tools/perf/util/expr.h          |  22 ++-
 tools/perf/util/expr.y          |  22 +--
 tools/perf/util/metricgroup.c   |  87 ++++++------
 tools/perf/util/stat-shadow.c   |  49 ++++---
 16 files changed, 793 insertions(+), 180 deletions(-)
 create mode 100644 tools/lib/api/hashmap.c
 create mode 100644 tools/lib/api/hashmap.h

-- 
2.26.2.761.g0e0b3e54be-goog

[PATCH 1/8] libbpf: Fix memory leak and possible double-free in hashmap__clear

[Ian Rogers]

From: Andrii Nakryiko <andriin@fb.com>

Fix memory leak in hashmap_clear() not freeing hashmap_entry structs for each
of the remaining entries. Also NULL-out bucket list to prevent possible
double-free between hashmap__clear() and hashmap__free().

Running test_progs-asan flavor clearly showed this problem.

Reported-by: Alston Tang <alston64@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-5-andriin@fb.com
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/bpf/hashmap.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/lib/bpf/hashmap.c b/tools/lib/bpf/hashmap.c
index 54c30c802070..cffb96202e0d 100644
--- a/tools/lib/bpf/hashmap.c
+++ b/tools/lib/bpf/hashmap.c
@@ -59,7 +59,14 @@ struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
 
 void hashmap__clear(struct hashmap *map)
 {
+	struct hashmap_entry *cur, *tmp;
+	int bkt;
+
+	hashmap__for_each_entry_safe(map, cur, tmp, bkt) {
+		free(cur);
+	}
 	free(map->buckets);
+	map->buckets = NULL;
 	map->cap = map->cap_bits = map->sz = 0;
 }
 
-- 
2.26.2.761.g0e0b3e54be-goog

[PATCH 2/8] libbpf hashmap: Remove unused #include

[Ian Rogers]

Remove #include of libbpf_internal.h that is unused.
Discussed in this thread:
https://lore.kernel.org/lkml/CAEf4BzZRmiEds_8R8g4vaAeWvJzPb4xYLnpF0X2VNY8oTzkphQ@mail.gmail.com/

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/bpf/hashmap.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/lib/bpf/hashmap.h b/tools/lib/bpf/hashmap.h
index bae8879cdf58..e823b35e7371 100644
--- a/tools/lib/bpf/hashmap.h
+++ b/tools/lib/bpf/hashmap.h
@@ -15,7 +15,6 @@
 #else
 #include <bits/reg.h>
 #endif
-#include "libbpf_internal.h"
 
 static inline size_t hash_bits(size_t h, int bits)
 {
-- 
2.26.2.761.g0e0b3e54be-goog

[PATCH 3/8] libbpf hashmap: Fix signedness warnings

[Ian Rogers]

Fixes the following warnings:

hashmap.c: In function ‘hashmap__clear’:
hashmap.h:150:20: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
  150 |  for (bkt = 0; bkt < map->cap; bkt++)        \

hashmap.c: In function ‘hashmap_grow’:
hashmap.h:150:20: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
  150 |  for (bkt = 0; bkt < map->cap; bkt++)        \

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/bpf/hashmap.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/lib/bpf/hashmap.c b/tools/lib/bpf/hashmap.c
index cffb96202e0d..a405dad068f5 100644
--- a/tools/lib/bpf/hashmap.c
+++ b/tools/lib/bpf/hashmap.c
@@ -60,7 +60,7 @@ struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
 void hashmap__clear(struct hashmap *map)
 {
 	struct hashmap_entry *cur, *tmp;
-	int bkt;
+	size_t bkt;
 
 	hashmap__for_each_entry_safe(map, cur, tmp, bkt) {
 		free(cur);
@@ -100,8 +100,7 @@ static int hashmap_grow(struct hashmap *map)
 	struct hashmap_entry **new_buckets;
 	struct hashmap_entry *cur, *tmp;
 	size_t new_cap_bits, new_cap;
-	size_t h;
-	int bkt;
+	size_t h, bkt;
 
 	new_cap_bits = map->cap_bits + 1;
 	if (new_cap_bits < HASHMAP_MIN_CAP_BITS)
-- 
2.26.2.761.g0e0b3e54be-goog

[PATCH 4/8] libbpf hashmap: Localize static hashmap__* symbols

[Ian Rogers]

Localize the hashmap__* symbols in libbpf.a. To allow for a version in
libapi.

Before:
$ nm libbpf.a
...
000000000002088a t hashmap_add_entry
000000000001712a t hashmap__append
0000000000020aa3 T hashmap__capacity
000000000002099c T hashmap__clear
00000000000208b3 t hashmap_del_entry
0000000000020fc1 T hashmap__delete
0000000000020f29 T hashmap__find
0000000000020c6c t hashmap_find_entry
0000000000020a61 T hashmap__free
0000000000020b08 t hashmap_grow
00000000000208dd T hashmap__init
0000000000020d35 T hashmap__insert
0000000000020ab5 t hashmap_needs_to_grow
0000000000020947 T hashmap__new
0000000000000775 t hashmap__set
00000000000212f8 t hashmap__set
0000000000020a91 T hashmap__size
...

After:
$ nm libbpf.a
...
000000000002088a t hashmap_add_entry
000000000001712a t hashmap__append
0000000000020aa3 t hashmap__capacity
000000000002099c t hashmap__clear
00000000000208b3 t hashmap_del_entry
0000000000020fc1 t hashmap__delete
0000000000020f29 t hashmap__find
0000000000020c6c t hashmap_find_entry
0000000000020a61 t hashmap__free
0000000000020b08 t hashmap_grow
00000000000208dd t hashmap__init
0000000000020d35 t hashmap__insert
0000000000020ab5 t hashmap_needs_to_grow
0000000000020947 t hashmap__new
0000000000000775 t hashmap__set
00000000000212f8 t hashmap__set
0000000000020a91 t hashmap__size
...

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/bpf/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index aee7f1a83c77..4a1cdbceb04e 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -20,6 +20,7 @@ srctree := $(patsubst %/,%,$(dir $(srctree)))
 endif
 
 INSTALL = install
+OBJCOPY ?= objcopy
 
 # Use DESTDIR for installing into a different root directory.
 # This is useful for building a package. The program will be
@@ -181,6 +182,7 @@ $(BPF_IN_SHARED): force elfdep zdep bpfdep $(BPF_HELPER_DEFS)
 
 $(BPF_IN_STATIC): force elfdep zdep bpfdep $(BPF_HELPER_DEFS)
 	$(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR)
+	$(Q)$(OBJCOPY) -w -L hashmap__\* $@
 
 $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h
 	$(QUIET_GEN)$(srctree)/scripts/bpf_helpers_doc.py --header \
-- 
2.26.2.761.g0e0b3e54be-goog

Re: [PATCH 4/8] libbpf hashmap: Localize static hashmap__* symbols

[Jiri Olsa]

On Thu, May 14, 2020 at 11:56:20PM -0700, Ian Rogers wrote:
> Localize the hashmap__* symbols in libbpf.a. To allow for a version in
> libapi.
> 
> Before:
> $ nm libbpf.a
> ...
> 000000000002088a t hashmap_add_entry
> 000000000001712a t hashmap__append
> 0000000000020aa3 T hashmap__capacity
> 000000000002099c T hashmap__clear
> 00000000000208b3 t hashmap_del_entry
> 0000000000020fc1 T hashmap__delete
> 0000000000020f29 T hashmap__find
> 0000000000020c6c t hashmap_find_entry
> 0000000000020a61 T hashmap__free
> 0000000000020b08 t hashmap_grow
> 00000000000208dd T hashmap__init
> 0000000000020d35 T hashmap__insert
> 0000000000020ab5 t hashmap_needs_to_grow
> 0000000000020947 T hashmap__new
> 0000000000000775 t hashmap__set
> 00000000000212f8 t hashmap__set
> 0000000000020a91 T hashmap__size
> ...
> 
> After:
> $ nm libbpf.a
> ...
> 000000000002088a t hashmap_add_entry
> 000000000001712a t hashmap__append
> 0000000000020aa3 t hashmap__capacity
> 000000000002099c t hashmap__clear
> 00000000000208b3 t hashmap_del_entry
> 0000000000020fc1 t hashmap__delete
> 0000000000020f29 t hashmap__find
> 0000000000020c6c t hashmap_find_entry
> 0000000000020a61 t hashmap__free
> 0000000000020b08 t hashmap_grow
> 00000000000208dd t hashmap__init
> 0000000000020d35 t hashmap__insert
> 0000000000020ab5 t hashmap_needs_to_grow
> 0000000000020947 t hashmap__new
> 0000000000000775 t hashmap__set
> 00000000000212f8 t hashmap__set
> 0000000000020a91 t hashmap__size
> ...

I think this will break bpf selftests which use hashmap,
we need to find some other way to include this

either to use it from libbpf directly, or use the api version
only if the libbpf is not compiled in perf, we could use
following to detect that:

      CFLAGS += -DHAVE_LIBBPF_SUPPORT
      $(call detected,CONFIG_LIBBPF)

jirka

Re: [PATCH 4/8] libbpf hashmap: Localize static hashmap__* symbols

[Arnaldo Carvalho de Melo]

Em Fri, May 15, 2020 at 11:17:07AM +0200, Jiri Olsa escreveu:
> On Thu, May 14, 2020 at 11:56:20PM -0700, Ian Rogers wrote:
> > Localize the hashmap__* symbols in libbpf.a. To allow for a version in
> > libapi.
> > 
> > Before:
> > $ nm libbpf.a
> > ...
> > 000000000002088a t hashmap_add_entry
> > 000000000001712a t hashmap__append
> > 0000000000020aa3 T hashmap__capacity
> > 000000000002099c T hashmap__clear
> > 00000000000208b3 t hashmap_del_entry
> > 0000000000020fc1 T hashmap__delete
> > 0000000000020f29 T hashmap__find
> > 0000000000020c6c t hashmap_find_entry
> > 0000000000020a61 T hashmap__free
> > 0000000000020b08 t hashmap_grow
> > 00000000000208dd T hashmap__init
> > 0000000000020d35 T hashmap__insert
> > 0000000000020ab5 t hashmap_needs_to_grow
> > 0000000000020947 T hashmap__new
> > 0000000000000775 t hashmap__set
> > 00000000000212f8 t hashmap__set
> > 0000000000020a91 T hashmap__size
> > ...
> > 
> > After:
> > $ nm libbpf.a
> > ...
> > 000000000002088a t hashmap_add_entry
> > 000000000001712a t hashmap__append
> > 0000000000020aa3 t hashmap__capacity
> > 000000000002099c t hashmap__clear
> > 00000000000208b3 t hashmap_del_entry
> > 0000000000020fc1 t hashmap__delete
> > 0000000000020f29 t hashmap__find
> > 0000000000020c6c t hashmap_find_entry
> > 0000000000020a61 t hashmap__free
> > 0000000000020b08 t hashmap_grow
> > 00000000000208dd t hashmap__init
> > 0000000000020d35 t hashmap__insert
> > 0000000000020ab5 t hashmap_needs_to_grow
> > 0000000000020947 t hashmap__new
> > 0000000000000775 t hashmap__set
> > 00000000000212f8 t hashmap__set
> > 0000000000020a91 t hashmap__size
> > ...
> 
> I think this will break bpf selftests which use hashmap,
> we need to find some other way to include this
> 
> either to use it from libbpf directly, or use the api version
> only if the libbpf is not compiled in perf, we could use
> following to detect that:
> 
>       CFLAGS += -DHAVE_LIBBPF_SUPPORT
>       $(call detected,CONFIG_LIBBPF)

And have it in tools/perf/util/ instead?


- Arnaldo

Re: [PATCH 4/8] libbpf hashmap: Localize static hashmap__* symbols

[Ian Rogers]

On Fri, May 15, 2020 at 7:29 AM Arnaldo Carvalho de Melo
<arnaldo.melo@gmail.com> wrote:
>
> Em Fri, May 15, 2020 at 11:17:07AM +0200, Jiri Olsa escreveu:
> > On Thu, May 14, 2020 at 11:56:20PM -0700, Ian Rogers wrote:
> > > Localize the hashmap__* symbols in libbpf.a. To allow for a version in
> > > libapi.
> > >
> > > Before:
> > > $ nm libbpf.a
> > > ...
> > > 000000000002088a t hashmap_add_entry
> > > 000000000001712a t hashmap__append
> > > 0000000000020aa3 T hashmap__capacity
> > > 000000000002099c T hashmap__clear
> > > 00000000000208b3 t hashmap_del_entry
> > > 0000000000020fc1 T hashmap__delete
> > > 0000000000020f29 T hashmap__find
> > > 0000000000020c6c t hashmap_find_entry
> > > 0000000000020a61 T hashmap__free
> > > 0000000000020b08 t hashmap_grow
> > > 00000000000208dd T hashmap__init
> > > 0000000000020d35 T hashmap__insert
> > > 0000000000020ab5 t hashmap_needs_to_grow
> > > 0000000000020947 T hashmap__new
> > > 0000000000000775 t hashmap__set
> > > 00000000000212f8 t hashmap__set
> > > 0000000000020a91 T hashmap__size
> > > ...
> > >
> > > After:
> > > $ nm libbpf.a
> > > ...
> > > 000000000002088a t hashmap_add_entry
> > > 000000000001712a t hashmap__append
> > > 0000000000020aa3 t hashmap__capacity
> > > 000000000002099c t hashmap__clear
> > > 00000000000208b3 t hashmap_del_entry
> > > 0000000000020fc1 t hashmap__delete
> > > 0000000000020f29 t hashmap__find
> > > 0000000000020c6c t hashmap_find_entry
> > > 0000000000020a61 t hashmap__free
> > > 0000000000020b08 t hashmap_grow
> > > 00000000000208dd t hashmap__init
> > > 0000000000020d35 t hashmap__insert
> > > 0000000000020ab5 t hashmap_needs_to_grow
> > > 0000000000020947 t hashmap__new
> > > 0000000000000775 t hashmap__set
> > > 00000000000212f8 t hashmap__set
> > > 0000000000020a91 t hashmap__size
> > > ...
> >
> > I think this will break bpf selftests which use hashmap,
> > we need to find some other way to include this
> >
> > either to use it from libbpf directly, or use the api version
> > only if the libbpf is not compiled in perf, we could use
> > following to detect that:
> >
> >       CFLAGS += -DHAVE_LIBBPF_SUPPORT
> >       $(call detected,CONFIG_LIBBPF)
>
> And have it in tools/perf/util/ instead?
>
>
> - Arnaldo

*sigh*

$ make -C tools/testing/selftests/bpf test_hashmap
make: Entering directory
'/usr/local/google/home/irogers/kernel-trees/kernel.org/tip/tools/testing/s
elftests/bpf'
 BINARY   test_hashmap
/usr/bin/ld: /tmp/ccEGGNw5.o: in function `test_hashmap_generic':
/usr/local/google/home/irogers/kernel-trees/kernel.org/tip/tools/testing/selftests/bpf/test_hashmap.
c:61: undefined reference to `hashmap__new'
...

My preference was to make hashmap a sharable API in tools, to benefit
not just perf but say things like libsymbol, libperf, etc. Moving it
into perf and using conditional compilation is kinda gross but having
libbpf tests depend on libapi also isn't ideal I guess. It is tempting
to just cut a hashmap from fresh cloth to avoid this and to share
among tools/. I don't know if the bpf folks have opinions?

I'll do a v2 using conditional compilation to see how bad it looks.

Thanks,
Ian

Re: [PATCH 4/8] libbpf hashmap: Localize static hashmap__* symbols

[Arnaldo Carvalho de Melo]

Em Fri, May 15, 2020 at 07:53:33AM -0700, Ian Rogers escreveu:
> On Fri, May 15, 2020 at 7:29 AM Arnaldo Carvalho de Melo
> <arnaldo.melo@gmail.com> wrote:
> >
> > Em Fri, May 15, 2020 at 11:17:07AM +0200, Jiri Olsa escreveu:
> > > On Thu, May 14, 2020 at 11:56:20PM -0700, Ian Rogers wrote:
> > > > Localize the hashmap__* symbols in libbpf.a. To allow for a version in
> > > > libapi.
> > > >
> > > > Before:
> > > > $ nm libbpf.a
> > > > ...
> > > > 000000000002088a t hashmap_add_entry
> > > > 000000000001712a t hashmap__append
> > > > 0000000000020aa3 T hashmap__capacity
> > > > 000000000002099c T hashmap__clear
> > > > 00000000000208b3 t hashmap_del_entry
> > > > 0000000000020fc1 T hashmap__delete
> > > > 0000000000020f29 T hashmap__find
> > > > 0000000000020c6c t hashmap_find_entry
> > > > 0000000000020a61 T hashmap__free
> > > > 0000000000020b08 t hashmap_grow
> > > > 00000000000208dd T hashmap__init
> > > > 0000000000020d35 T hashmap__insert
> > > > 0000000000020ab5 t hashmap_needs_to_grow
> > > > 0000000000020947 T hashmap__new
> > > > 0000000000000775 t hashmap__set
> > > > 00000000000212f8 t hashmap__set
> > > > 0000000000020a91 T hashmap__size
> > > > ...
> > > >
> > > > After:
> > > > $ nm libbpf.a
> > > > ...
> > > > 000000000002088a t hashmap_add_entry
> > > > 000000000001712a t hashmap__append
> > > > 0000000000020aa3 t hashmap__capacity
> > > > 000000000002099c t hashmap__clear
> > > > 00000000000208b3 t hashmap_del_entry
> > > > 0000000000020fc1 t hashmap__delete
> > > > 0000000000020f29 t hashmap__find
> > > > 0000000000020c6c t hashmap_find_entry
> > > > 0000000000020a61 t hashmap__free
> > > > 0000000000020b08 t hashmap_grow
> > > > 00000000000208dd t hashmap__init
> > > > 0000000000020d35 t hashmap__insert
> > > > 0000000000020ab5 t hashmap_needs_to_grow
> > > > 0000000000020947 t hashmap__new
> > > > 0000000000000775 t hashmap__set
> > > > 00000000000212f8 t hashmap__set
> > > > 0000000000020a91 t hashmap__size
> > > > ...
> > >
> > > I think this will break bpf selftests which use hashmap,
> > > we need to find some other way to include this
> > >
> > > either to use it from libbpf directly, or use the api version
> > > only if the libbpf is not compiled in perf, we could use
> > > following to detect that:
> > >
> > >       CFLAGS += -DHAVE_LIBBPF_SUPPORT
> > >       $(call detected,CONFIG_LIBBPF)
> >
> > And have it in tools/perf/util/ instead?
 
> *sigh*
 
> $ make -C tools/testing/selftests/bpf test_hashmap
> make: Entering directory
> '/usr/local/google/home/irogers/kernel-trees/kernel.org/tip/tools/testing/s
> elftests/bpf'
>  BINARY   test_hashmap
> /usr/bin/ld: /tmp/ccEGGNw5.o: in function `test_hashmap_generic':
> /usr/local/google/home/irogers/kernel-trees/kernel.org/tip/tools/testing/selftests/bpf/test_hashmap.
> c:61: undefined reference to `hashmap__new'
> ...
 
> My preference was to make hashmap a sharable API in tools, to benefit

That is my preference as well, I'm not defending having it in
tools/perf/util/, just saying that that is a possible way to make
progress with the current situation...

> not just perf but say things like libsymbol, libperf, etc. Moving it
> into perf and using conditional compilation is kinda gross but having
> libbpf tests depend on libapi also isn't ideal I guess. It is tempting
> to just cut a hashmap from fresh cloth to avoid this and to share
> among tools/. I don't know if the bpf folks have opinions?
> 
> I'll do a v2 using conditional compilation to see how bad it looks.

Cool, lets see how it looks.

- Arnaldo

Re: [PATCH 4/8] libbpf hashmap: Localize static hashmap__* symbols

[Ian Rogers]

On Fri, May 15, 2020 at 9:31 AM Arnaldo Carvalho de Melo
<arnaldo.melo@gmail.com> wrote:
>
> Em Fri, May 15, 2020 at 07:53:33AM -0700, Ian Rogers escreveu:
> > On Fri, May 15, 2020 at 7:29 AM Arnaldo Carvalho de Melo
> > <arnaldo.melo@gmail.com> wrote:
> > >
> > > Em Fri, May 15, 2020 at 11:17:07AM +0200, Jiri Olsa escreveu:
> > > > On Thu, May 14, 2020 at 11:56:20PM -0700, Ian Rogers wrote:
> > > > > Localize the hashmap__* symbols in libbpf.a. To allow for a version in
> > > > > libapi.
> > > > >
> > > > > Before:
> > > > > $ nm libbpf.a
> > > > > ...
> > > > > 000000000002088a t hashmap_add_entry
> > > > > 000000000001712a t hashmap__append
> > > > > 0000000000020aa3 T hashmap__capacity
> > > > > 000000000002099c T hashmap__clear
> > > > > 00000000000208b3 t hashmap_del_entry
> > > > > 0000000000020fc1 T hashmap__delete
> > > > > 0000000000020f29 T hashmap__find
> > > > > 0000000000020c6c t hashmap_find_entry
> > > > > 0000000000020a61 T hashmap__free
> > > > > 0000000000020b08 t hashmap_grow
> > > > > 00000000000208dd T hashmap__init
> > > > > 0000000000020d35 T hashmap__insert
> > > > > 0000000000020ab5 t hashmap_needs_to_grow
> > > > > 0000000000020947 T hashmap__new
> > > > > 0000000000000775 t hashmap__set
> > > > > 00000000000212f8 t hashmap__set
> > > > > 0000000000020a91 T hashmap__size
> > > > > ...
> > > > >
> > > > > After:
> > > > > $ nm libbpf.a
> > > > > ...
> > > > > 000000000002088a t hashmap_add_entry
> > > > > 000000000001712a t hashmap__append
> > > > > 0000000000020aa3 t hashmap__capacity
> > > > > 000000000002099c t hashmap__clear
> > > > > 00000000000208b3 t hashmap_del_entry
> > > > > 0000000000020fc1 t hashmap__delete
> > > > > 0000000000020f29 t hashmap__find
> > > > > 0000000000020c6c t hashmap_find_entry
> > > > > 0000000000020a61 t hashmap__free
> > > > > 0000000000020b08 t hashmap_grow
> > > > > 00000000000208dd t hashmap__init
> > > > > 0000000000020d35 t hashmap__insert
> > > > > 0000000000020ab5 t hashmap_needs_to_grow
> > > > > 0000000000020947 t hashmap__new
> > > > > 0000000000000775 t hashmap__set
> > > > > 00000000000212f8 t hashmap__set
> > > > > 0000000000020a91 t hashmap__size
> > > > > ...
> > > >
> > > > I think this will break bpf selftests which use hashmap,
> > > > we need to find some other way to include this
> > > >
> > > > either to use it from libbpf directly, or use the api version
> > > > only if the libbpf is not compiled in perf, we could use
> > > > following to detect that:
> > > >
> > > >       CFLAGS += -DHAVE_LIBBPF_SUPPORT
> > > >       $(call detected,CONFIG_LIBBPF)
> > >
> > > And have it in tools/perf/util/ instead?
>
> > *sigh*
>
> > $ make -C tools/testing/selftests/bpf test_hashmap
> > make: Entering directory
> > '/usr/local/google/home/irogers/kernel-trees/kernel.org/tip/tools/testing/s
> > elftests/bpf'
> >  BINARY   test_hashmap
> > /usr/bin/ld: /tmp/ccEGGNw5.o: in function `test_hashmap_generic':
> > /usr/local/google/home/irogers/kernel-trees/kernel.org/tip/tools/testing/selftests/bpf/test_hashmap.
> > c:61: undefined reference to `hashmap__new'
> > ...
>
> > My preference was to make hashmap a sharable API in tools, to benefit
>
> That is my preference as well, I'm not defending having it in
> tools/perf/util/, just saying that that is a possible way to make
> progress with the current situation...

Thanks, it'd be nice to be expedient as both Jiri and myself are
changing code in this area. v2 is up for review here:
https://lore.kernel.org/lkml/20200515165007.217120-8-irogers@google.com/
An ifdef when the hashmap.h is used, and one in the build. It could be worse.

Thanks,
Ian

> > not just perf but say things like libsymbol, libperf, etc. Moving it
> > into perf and using conditional compilation is kinda gross but having
> > libbpf tests depend on libapi also isn't ideal I guess. It is tempting
> > to just cut a hashmap from fresh cloth to avoid this and to share
> > among tools/. I don't know if the bpf folks have opinions?
> >
> > I'll do a v2 using conditional compilation to see how bad it looks.
>
> Cool, lets see how it looks.
>
> - Arnaldo

[PATCH 5/8] tools lib/api: Copy libbpf hashmap to libapi

[Ian Rogers]

Allow use of hashmap in more than just libbpf, where it isn't an
exported symbol. Place in libapi as that is a required part of
tools/perf whereas libbpf is currently optional.
Modify perf's check-headers.sh script to check that the files are kept
in sync, in the same way kernel headers are checked. This will warn if
they are out of sync at the start of a perf build.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/api/Build         |   1 +
 tools/lib/api/hashmap.c     | 238 ++++++++++++++++++++++++++++++++++++
 tools/lib/api/hashmap.h     | 177 +++++++++++++++++++++++++++
 tools/perf/check-headers.sh |   4 +
 4 files changed, 420 insertions(+)
 create mode 100644 tools/lib/api/hashmap.c
 create mode 100644 tools/lib/api/hashmap.h

diff --git a/tools/lib/api/Build b/tools/lib/api/Build
index 6e2373db5598..2c8787a88080 100644
--- a/tools/lib/api/Build
+++ b/tools/lib/api/Build
@@ -2,6 +2,7 @@ libapi-y += fd/
 libapi-y += fs/
 libapi-y += cpu.o
 libapi-y += debug.o
+libapi-y += hashmap.o
 libapi-y += str_error_r.o
 
 $(OUTPUT)str_error_r.o: ../str_error_r.c FORCE
diff --git a/tools/lib/api/hashmap.c b/tools/lib/api/hashmap.c
new file mode 100644
index 000000000000..a405dad068f5
--- /dev/null
+++ b/tools/lib/api/hashmap.c
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+
+/*
+ * Generic non-thread safe hash map implementation.
+ *
+ * Copyright (c) 2019 Facebook
+ */
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <linux/err.h>
+#include "hashmap.h"
+
+/* make sure libbpf doesn't use kernel-only integer typedefs */
+#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
+
+/* start with 4 buckets */
+#define HASHMAP_MIN_CAP_BITS 2
+
+static void hashmap_add_entry(struct hashmap_entry **pprev,
+			      struct hashmap_entry *entry)
+{
+	entry->next = *pprev;
+	*pprev = entry;
+}
+
+static void hashmap_del_entry(struct hashmap_entry **pprev,
+			      struct hashmap_entry *entry)
+{
+	*pprev = entry->next;
+	entry->next = NULL;
+}
+
+void hashmap__init(struct hashmap *map, hashmap_hash_fn hash_fn,
+		   hashmap_equal_fn equal_fn, void *ctx)
+{
+	map->hash_fn = hash_fn;
+	map->equal_fn = equal_fn;
+	map->ctx = ctx;
+
+	map->buckets = NULL;
+	map->cap = 0;
+	map->cap_bits = 0;
+	map->sz = 0;
+}
+
+struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
+			     hashmap_equal_fn equal_fn,
+			     void *ctx)
+{
+	struct hashmap *map = malloc(sizeof(struct hashmap));
+
+	if (!map)
+		return ERR_PTR(-ENOMEM);
+	hashmap__init(map, hash_fn, equal_fn, ctx);
+	return map;
+}
+
+void hashmap__clear(struct hashmap *map)
+{
+	struct hashmap_entry *cur, *tmp;
+	size_t bkt;
+
+	hashmap__for_each_entry_safe(map, cur, tmp, bkt) {
+		free(cur);
+	}
+	free(map->buckets);
+	map->buckets = NULL;
+	map->cap = map->cap_bits = map->sz = 0;
+}
+
+void hashmap__free(struct hashmap *map)
+{
+	if (!map)
+		return;
+
+	hashmap__clear(map);
+	free(map);
+}
+
+size_t hashmap__size(const struct hashmap *map)
+{
+	return map->sz;
+}
+
+size_t hashmap__capacity(const struct hashmap *map)
+{
+	return map->cap;
+}
+
+static bool hashmap_needs_to_grow(struct hashmap *map)
+{
+	/* grow if empty or more than 75% filled */
+	return (map->cap == 0) || ((map->sz + 1) * 4 / 3 > map->cap);
+}
+
+static int hashmap_grow(struct hashmap *map)
+{
+	struct hashmap_entry **new_buckets;
+	struct hashmap_entry *cur, *tmp;
+	size_t new_cap_bits, new_cap;
+	size_t h, bkt;
+
+	new_cap_bits = map->cap_bits + 1;
+	if (new_cap_bits < HASHMAP_MIN_CAP_BITS)
+		new_cap_bits = HASHMAP_MIN_CAP_BITS;
+
+	new_cap = 1UL << new_cap_bits;
+	new_buckets = calloc(new_cap, sizeof(new_buckets[0]));
+	if (!new_buckets)
+		return -ENOMEM;
+
+	hashmap__for_each_entry_safe(map, cur, tmp, bkt) {
+		h = hash_bits(map->hash_fn(cur->key, map->ctx), new_cap_bits);
+		hashmap_add_entry(&new_buckets[h], cur);
+	}
+
+	map->cap = new_cap;
+	map->cap_bits = new_cap_bits;
+	free(map->buckets);
+	map->buckets = new_buckets;
+
+	return 0;
+}
+
+static bool hashmap_find_entry(const struct hashmap *map,
+			       const void *key, size_t hash,
+			       struct hashmap_entry ***pprev,
+			       struct hashmap_entry **entry)
+{
+	struct hashmap_entry *cur, **prev_ptr;
+
+	if (!map->buckets)
+		return false;
+
+	for (prev_ptr = &map->buckets[hash], cur = *prev_ptr;
+	     cur;
+	     prev_ptr = &cur->next, cur = cur->next) {
+		if (map->equal_fn(cur->key, key, map->ctx)) {
+			if (pprev)
+				*pprev = prev_ptr;
+			*entry = cur;
+			return true;
+		}
+	}
+
+	return false;
+}
+
+int hashmap__insert(struct hashmap *map, const void *key, void *value,
+		    enum hashmap_insert_strategy strategy,
+		    const void **old_key, void **old_value)
+{
+	struct hashmap_entry *entry;
+	size_t h;
+	int err;
+
+	if (old_key)
+		*old_key = NULL;
+	if (old_value)
+		*old_value = NULL;
+
+	h = hash_bits(map->hash_fn(key, map->ctx), map->cap_bits);
+	if (strategy != HASHMAP_APPEND &&
+	    hashmap_find_entry(map, key, h, NULL, &entry)) {
+		if (old_key)
+			*old_key = entry->key;
+		if (old_value)
+			*old_value = entry->value;
+
+		if (strategy == HASHMAP_SET || strategy == HASHMAP_UPDATE) {
+			entry->key = key;
+			entry->value = value;
+			return 0;
+		} else if (strategy == HASHMAP_ADD) {
+			return -EEXIST;
+		}
+	}
+
+	if (strategy == HASHMAP_UPDATE)
+		return -ENOENT;
+
+	if (hashmap_needs_to_grow(map)) {
+		err = hashmap_grow(map);
+		if (err)
+			return err;
+		h = hash_bits(map->hash_fn(key, map->ctx), map->cap_bits);
+	}
+
+	entry = malloc(sizeof(struct hashmap_entry));
+	if (!entry)
+		return -ENOMEM;
+
+	entry->key = key;
+	entry->value = value;
+	hashmap_add_entry(&map->buckets[h], entry);
+	map->sz++;
+
+	return 0;
+}
+
+bool hashmap__find(const struct hashmap *map, const void *key, void **value)
+{
+	struct hashmap_entry *entry;
+	size_t h;
+
+	h = hash_bits(map->hash_fn(key, map->ctx), map->cap_bits);
+	if (!hashmap_find_entry(map, key, h, NULL, &entry))
+		return false;
+
+	if (value)
+		*value = entry->value;
+	return true;
+}
+
+bool hashmap__delete(struct hashmap *map, const void *key,
+		     const void **old_key, void **old_value)
+{
+	struct hashmap_entry **pprev, *entry;
+	size_t h;
+
+	h = hash_bits(map->hash_fn(key, map->ctx), map->cap_bits);
+	if (!hashmap_find_entry(map, key, h, &pprev, &entry))
+		return false;
+
+	if (old_key)
+		*old_key = entry->key;
+	if (old_value)
+		*old_value = entry->value;
+
+	hashmap_del_entry(pprev, entry);
+	free(entry);
+	map->sz--;
+
+	return true;
+}
+
diff --git a/tools/lib/api/hashmap.h b/tools/lib/api/hashmap.h
new file mode 100644
index 000000000000..e823b35e7371
--- /dev/null
+++ b/tools/lib/api/hashmap.h
@@ -0,0 +1,177 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/*
+ * Generic non-thread safe hash map implementation.
+ *
+ * Copyright (c) 2019 Facebook
+ */
+#ifndef __LIBBPF_HASHMAP_H
+#define __LIBBPF_HASHMAP_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#ifdef __GLIBC__
+#include <bits/wordsize.h>
+#else
+#include <bits/reg.h>
+#endif
+
+static inline size_t hash_bits(size_t h, int bits)
+{
+	/* shuffle bits and return requested number of upper bits */
+	return (h * 11400714819323198485llu) >> (__WORDSIZE - bits);
+}
+
+typedef size_t (*hashmap_hash_fn)(const void *key, void *ctx);
+typedef bool (*hashmap_equal_fn)(const void *key1, const void *key2, void *ctx);
+
+struct hashmap_entry {
+	const void *key;
+	void *value;
+	struct hashmap_entry *next;
+};
+
+struct hashmap {
+	hashmap_hash_fn hash_fn;
+	hashmap_equal_fn equal_fn;
+	void *ctx;
+
+	struct hashmap_entry **buckets;
+	size_t cap;
+	size_t cap_bits;
+	size_t sz;
+};
+
+#define HASHMAP_INIT(hash_fn, equal_fn, ctx) {	\
+	.hash_fn = (hash_fn),			\
+	.equal_fn = (equal_fn),			\
+	.ctx = (ctx),				\
+	.buckets = NULL,			\
+	.cap = 0,				\
+	.cap_bits = 0,				\
+	.sz = 0,				\
+}
+
+void hashmap__init(struct hashmap *map, hashmap_hash_fn hash_fn,
+		   hashmap_equal_fn equal_fn, void *ctx);
+struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
+			     hashmap_equal_fn equal_fn,
+			     void *ctx);
+void hashmap__clear(struct hashmap *map);
+void hashmap__free(struct hashmap *map);
+
+size_t hashmap__size(const struct hashmap *map);
+size_t hashmap__capacity(const struct hashmap *map);
+
+/*
+ * Hashmap insertion strategy:
+ * - HASHMAP_ADD - only add key/value if key doesn't exist yet;
+ * - HASHMAP_SET - add key/value pair if key doesn't exist yet; otherwise,
+ *   update value;
+ * - HASHMAP_UPDATE - update value, if key already exists; otherwise, do
+ *   nothing and return -ENOENT;
+ * - HASHMAP_APPEND - always add key/value pair, even if key already exists.
+ *   This turns hashmap into a multimap by allowing multiple values to be
+ *   associated with the same key. Most useful read API for such hashmap is
+ *   hashmap__for_each_key_entry() iteration. If hashmap__find() is still
+ *   used, it will return last inserted key/value entry (first in a bucket
+ *   chain).
+ */
+enum hashmap_insert_strategy {
+	HASHMAP_ADD,
+	HASHMAP_SET,
+	HASHMAP_UPDATE,
+	HASHMAP_APPEND,
+};
+
+/*
+ * hashmap__insert() adds key/value entry w/ various semantics, depending on
+ * provided strategy value. If a given key/value pair replaced already
+ * existing key/value pair, both old key and old value will be returned
+ * through old_key and old_value to allow calling code do proper memory
+ * management.
+ */
+int hashmap__insert(struct hashmap *map, const void *key, void *value,
+		    enum hashmap_insert_strategy strategy,
+		    const void **old_key, void **old_value);
+
+static inline int hashmap__add(struct hashmap *map,
+			       const void *key, void *value)
+{
+	return hashmap__insert(map, key, value, HASHMAP_ADD, NULL, NULL);
+}
+
+static inline int hashmap__set(struct hashmap *map,
+			       const void *key, void *value,
+			       const void **old_key, void **old_value)
+{
+	return hashmap__insert(map, key, value, HASHMAP_SET,
+			       old_key, old_value);
+}
+
+static inline int hashmap__update(struct hashmap *map,
+				  const void *key, void *value,
+				  const void **old_key, void **old_value)
+{
+	return hashmap__insert(map, key, value, HASHMAP_UPDATE,
+			       old_key, old_value);
+}
+
+static inline int hashmap__append(struct hashmap *map,
+				  const void *key, void *value)
+{
+	return hashmap__insert(map, key, value, HASHMAP_APPEND, NULL, NULL);
+}
+
+bool hashmap__delete(struct hashmap *map, const void *key,
+		     const void **old_key, void **old_value);
+
+bool hashmap__find(const struct hashmap *map, const void *key, void **value);
+
+/*
+ * hashmap__for_each_entry - iterate over all entries in hashmap
+ * @map: hashmap to iterate
+ * @cur: struct hashmap_entry * used as a loop cursor
+ * @bkt: integer used as a bucket loop cursor
+ */
+#define hashmap__for_each_entry(map, cur, bkt)				    \
+	for (bkt = 0; bkt < map->cap; bkt++)				    \
+		for (cur = map->buckets[bkt]; cur; cur = cur->next)
+
+/*
+ * hashmap__for_each_entry_safe - iterate over all entries in hashmap, safe
+ * against removals
+ * @map: hashmap to iterate
+ * @cur: struct hashmap_entry * used as a loop cursor
+ * @tmp: struct hashmap_entry * used as a temporary next cursor storage
+ * @bkt: integer used as a bucket loop cursor
+ */
+#define hashmap__for_each_entry_safe(map, cur, tmp, bkt)		    \
+	for (bkt = 0; bkt < map->cap; bkt++)				    \
+		for (cur = map->buckets[bkt];				    \
+		     cur && ({tmp = cur->next; true; });		    \
+		     cur = tmp)
+
+/*
+ * hashmap__for_each_key_entry - iterate over entries associated with given key
+ * @map: hashmap to iterate
+ * @cur: struct hashmap_entry * used as a loop cursor
+ * @key: key to iterate entries for
+ */
+#define hashmap__for_each_key_entry(map, cur, _key)			    \
+	for (cur = ({ size_t bkt = hash_bits(map->hash_fn((_key), map->ctx),\
+					     map->cap_bits);		    \
+		     map->buckets ? map->buckets[bkt] : NULL; });	    \
+	     cur;							    \
+	     cur = cur->next)						    \
+		if (map->equal_fn(cur->key, (_key), map->ctx))
+
+#define hashmap__for_each_key_entry_safe(map, cur, tmp, _key)		    \
+	for (cur = ({ size_t bkt = hash_bits(map->hash_fn((_key), map->ctx),\
+					     map->cap_bits);		    \
+		     cur = map->buckets ? map->buckets[bkt] : NULL; });	    \
+	     cur && ({ tmp = cur->next; true; });			    \
+	     cur = tmp)							    \
+		if (map->equal_fn(cur->key, (_key), map->ctx))
+
+#endif /* __LIBBPF_HASHMAP_H */
diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
index cf147db4e5ca..87fcffa33a4d 100755
--- a/tools/perf/check-headers.sh
+++ b/tools/perf/check-headers.sh
@@ -128,4 +128,8 @@ check arch/x86/lib/insn.c             '-I "^#include [\"<]\(../include/\)*asm/in
 # diff non-symmetric files
 check_2 tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
 
+# check duplicated library files
+check_2 tools/lib/api/hashmap.h tools/lib/bpf/hashmap.h
+check_2 tools/lib/api/hashmap.c tools/lib/bpf/hashmap.c
+
 cd tools/perf
-- 
2.26.2.761.g0e0b3e54be-goog

[PATCH 6/8] perf test: Provide a subtest callback to ask for the reason for skipping a subtest

[Ian Rogers]

Now subtests can inform why a test was skipped. The upcoming patch
improvint PMU event metric testing will use it.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200513212933.41273-1-irogers@google.com
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/builtin-test.c | 11 +++++++++--
 tools/perf/tests/tests.h        |  1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 3471ec52ea11..baee735e6aa5 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -429,8 +429,15 @@ static int test_and_print(struct test *t, bool force_skip, int subtest)
 	case TEST_OK:
 		pr_info(" Ok\n");
 		break;
-	case TEST_SKIP:
-		color_fprintf(stderr, PERF_COLOR_YELLOW, " Skip\n");
+	case TEST_SKIP: {
+		const char *skip_reason = NULL;
+		if (t->subtest.skip_reason)
+			skip_reason = t->subtest.skip_reason(subtest);
+		if (skip_reason)
+			color_fprintf(stderr, PERF_COLOR_YELLOW, " Skip (%s)\n", skip_reason);
+		else
+			color_fprintf(stderr, PERF_COLOR_YELLOW, " Skip\n");
+	}
 		break;
 	case TEST_FAIL:
 	default:
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index d6d4ac34eeb7..88e45aeab94f 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -34,6 +34,7 @@ struct test {
 		bool skip_if_fail;
 		int (*get_nr)(void);
 		const char *(*get_desc)(int subtest);
+		const char *(*skip_reason)(int subtest);
 	} subtest;
 	bool (*is_supported)(void);
 	void *priv;
-- 
2.26.2.761.g0e0b3e54be-goog

[PATCH 7/8] perf test: Improve pmu event metric testing

[Ian Rogers]

Break pmu-events test into 2 and add a test to verify that all pmu
metric expressions simply parse. Try to parse all metric ids/events,
skip/warn if metrics for the current architecture fail to parse. To
support warning for a skip, and an ability for a subtest to describe why
it skips.

Tested on power9, skylakex, haswell, broadwell, westmere, sandybridge and
ivybridge.

May skip/warn on other architectures if metrics are invalid. In
particular s390 is untested, but its expressions are trivial. The
untested architectures with expressions are power8, cascadelakex,
tremontx, skylake, jaketown, ivytown and variants of haswell and
broadwell.

v3. addresses review comments from John Garry <john.garry@huawei.com>,
Jiri Olsa <jolsa@redhat.com> and Arnaldo Carvalho de Melo
<acme@kernel.org>.
v2. changes the commit message as event parsing errors no longer cause
the test to fail.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200513212933.41273-1-irogers@google.com
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/builtin-test.c |   7 ++
 tools/perf/tests/pmu-events.c   | 168 ++++++++++++++++++++++++++++++--
 tools/perf/tests/tests.h        |   3 +
 3 files changed, 172 insertions(+), 6 deletions(-)

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index baee735e6aa5..9553f8061772 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -75,6 +75,13 @@ static struct test generic_tests[] = {
 	{
 		.desc = "PMU events",
 		.func = test__pmu_events,
+		.subtest = {
+			.skip_if_fail	= false,
+			.get_nr		= test__pmu_events_subtest_get_nr,
+			.get_desc	= test__pmu_events_subtest_get_desc,
+			.skip_reason	= test__pmu_events_subtest_skip_reason,
+		},
+
 	},
 	{
 		.desc = "DSO data read",
diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
index d64261da8bf7..e21f0addcfbb 100644
--- a/tools/perf/tests/pmu-events.c
+++ b/tools/perf/tests/pmu-events.c
@@ -8,6 +8,9 @@
 #include <linux/zalloc.h>
 #include "debug.h"
 #include "../pmu-events/pmu-events.h"
+#include "util/evlist.h"
+#include "util/expr.h"
+#include "util/parse-events.h"
 
 struct perf_pmu_test_event {
 	struct pmu_event event;
@@ -144,7 +147,7 @@ static struct pmu_events_map *__test_pmu_get_events_map(void)
 }
 
 /* Verify generated events from pmu-events.c is as expected */
-static int __test_pmu_event_table(void)
+static int test_pmu_event_table(void)
 {
 	struct pmu_events_map *map = __test_pmu_get_events_map();
 	struct pmu_event *table;
@@ -347,14 +350,11 @@ static int __test__pmu_event_aliases(char *pmu_name, int *count)
 	return res;
 }
 
-int test__pmu_events(struct test *test __maybe_unused,
-		     int subtest __maybe_unused)
+
+static int test_aliases(void)
 {
 	struct perf_pmu *pmu = NULL;
 
-	if (__test_pmu_event_table())
-		return -1;
-
 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
 		int count = 0;
 
@@ -377,3 +377,159 @@ int test__pmu_events(struct test *test __maybe_unused,
 
 	return 0;
 }
+
+static bool is_number(const char *str)
+{
+	char *end_ptr;
+
+	strtod(str, &end_ptr);
+	return end_ptr != str;
+}
+
+static int check_parse_id(const char *id, bool same_cpu, struct pmu_event *pe)
+{
+	struct parse_events_error error;
+	struct evlist *evlist;
+	int ret;
+
+	/* Numbers are always valid. */
+	if (is_number(id))
+		return 0;
+
+	evlist = evlist__new();
+	memset(&error, 0, sizeof(error));
+	ret = parse_events(evlist, id, &error);
+	if (ret && same_cpu) {
+		pr_warning("Parse event failed metric '%s' id '%s' expr '%s'\n",
+			pe->metric_name, id, pe->metric_expr);
+		pr_warning("Error string '%s' help '%s'\n", error.str,
+			error.help);
+	} else if (ret) {
+		pr_debug3("Parse event failed, but for an event that may not be supported by this CPU.\nid '%s' metric '%s' expr '%s'\n",
+			  id, pe->metric_name, pe->metric_expr);
+		ret = 0;
+	}
+	evlist__delete(evlist);
+	free(error.str);
+	free(error.help);
+	free(error.first_str);
+	free(error.first_help);
+	return ret;
+}
+
+static void expr_failure(const char *msg,
+			 const struct pmu_events_map *map,
+			 const struct pmu_event *pe)
+{
+	pr_debug("%s for map %s %s %s\n",
+		msg, map->cpuid, map->version, map->type);
+	pr_debug("On metric %s\n", pe->metric_name);
+	pr_debug("On expression %s\n", pe->metric_expr);
+}
+
+static int test_parsing(void)
+{
+	struct pmu_events_map *cpus_map = perf_pmu__find_map(NULL);
+	struct pmu_events_map *map;
+	struct pmu_event *pe;
+	int i, j, k;
+	const char **ids;
+	int idnum;
+	int ret = 0;
+	struct expr_parse_ctx ctx;
+	double result;
+
+	i = 0;
+	for (;;) {
+		map = &pmu_events_map[i++];
+		if (!map->table)
+			break;
+		j = 0;
+		for (;;) {
+			pe = &map->table[j++];
+			if (!pe->name && !pe->metric_group && !pe->metric_name)
+				break;
+			if (!pe->metric_expr)
+				continue;
+			if (expr__find_other(pe->metric_expr, NULL,
+						&ids, &idnum, 0) < 0) {
+				expr_failure("Parse other failed", map, pe);
+				ret++;
+				continue;
+			}
+			expr__ctx_init(&ctx);
+
+			/*
+			 * Add all ids with a made up value. The value may
+			 * trigger divide by zero when subtracted and so try to
+			 * make them unique.
+			 */
+			for (k = 0; k < idnum; k++)
+				expr__add_id(&ctx, ids[k], k + 1);
+
+			for (k = 0; k < idnum; k++) {
+				if (check_parse_id(ids[k], map == cpus_map, pe))
+					ret++;
+			}
+
+			if (expr__parse(&result, &ctx, pe->metric_expr, 0)) {
+				expr_failure("Parse failed", map, pe);
+				ret++;
+			}
+			for (k = 0; k < idnum; k++)
+				zfree(&ids[k]);
+			free(ids);
+		}
+	}
+	/* TODO: fail when not ok */
+	return ret == 0 ? TEST_OK : TEST_SKIP;
+}
+
+static const struct {
+	int (*func)(void);
+	const char *desc;
+} pmu_events_testcase_table[] = {
+	{
+		.func = test_pmu_event_table,
+		.desc = "PMU event table sanity",
+	},
+	{
+		.func = test_aliases,
+		.desc = "PMU event map aliases",
+	},
+	{
+		.func = test_parsing,
+		.desc = "Parsing of PMU event table metrics",
+	},
+};
+
+const char *test__pmu_events_subtest_get_desc(int subtest)
+{
+	if (subtest < 0 ||
+	    subtest >= (int)ARRAY_SIZE(pmu_events_testcase_table))
+		return NULL;
+	return pmu_events_testcase_table[subtest].desc;
+}
+
+const char *test__pmu_events_subtest_skip_reason(int subtest)
+{
+	if (subtest < 0 ||
+	    subtest >= (int)ARRAY_SIZE(pmu_events_testcase_table))
+		return NULL;
+	if (pmu_events_testcase_table[subtest].func != test_parsing)
+		return NULL;
+	return "some metrics failed";
+}
+
+int test__pmu_events_subtest_get_nr(void)
+{
+	return (int)ARRAY_SIZE(pmu_events_testcase_table);
+}
+
+int test__pmu_events(struct test *test __maybe_unused, int subtest)
+{
+	if (subtest < 0 ||
+	    subtest >= (int)ARRAY_SIZE(pmu_events_testcase_table))
+		return TEST_FAIL;
+	return pmu_events_testcase_table[subtest].func();
+}
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 88e45aeab94f..6c6c4b6a4796 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -51,6 +51,9 @@ int test__perf_evsel__tp_sched_test(struct test *test, int subtest);
 int test__syscall_openat_tp_fields(struct test *test, int subtest);
 int test__pmu(struct test *test, int subtest);
 int test__pmu_events(struct test *test, int subtest);
+const char *test__pmu_events_subtest_get_desc(int subtest);
+const char *test__pmu_events_subtest_skip_reason(int subtest);
+int test__pmu_events_subtest_get_nr(void);
 int test__attr(struct test *test, int subtest);
 int test__dso_data(struct test *test, int subtest);
 int test__dso_data_cache(struct test *test, int subtest);
-- 
2.26.2.761.g0e0b3e54be-goog

[PATCH 8/8] perf expr: Migrate expr ids table to a hashmap

[Ian Rogers]

Use a hashmap between a char* string and a double* value. While bpf's
hashmap entries are size_t in size, we can't guarantee sizeof(size_t) >=
sizeof(double). Avoid a memory allocation when gathering ids by making 0.0
a special value encoded as NULL.

Original map suggestion by Andi Kleen:
https://lore.kernel.org/lkml/20200224210308.GQ160988@tassilo.jf.intel.com/
and seconded by Jiri Olsa:
https://lore.kernel.org/lkml/20200423112915.GH1136647@krava/

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/expr.c       |  40 ++++++-----
 tools/perf/tests/pmu-events.c |  25 +++----
 tools/perf/util/expr.c        | 129 +++++++++++++++++++---------------
 tools/perf/util/expr.h        |  22 +++---
 tools/perf/util/expr.y        |  22 +-----
 tools/perf/util/metricgroup.c |  87 +++++++++++------------
 tools/perf/util/stat-shadow.c |  49 ++++++++-----
 7 files changed, 193 insertions(+), 181 deletions(-)

diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
index 3f742612776a..5e606fd5a2c6 100644
--- a/tools/perf/tests/expr.c
+++ b/tools/perf/tests/expr.c
@@ -19,11 +19,9 @@ static int test(struct expr_parse_ctx *ctx, const char *e, double val2)
 int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
 {
 	const char *p;
-	const char **other;
-	double val;
-	int i, ret;
+	double val, *val_ptr;
+	int ret;
 	struct expr_parse_ctx ctx;
-	int num_other;
 
 	expr__ctx_init(&ctx);
 	expr__add_id(&ctx, "FOO", 1);
@@ -52,25 +50,29 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
 	ret = expr__parse(&val, &ctx, p, 1);
 	TEST_ASSERT_VAL("missing operand", ret == -1);
 
+	hashmap__clear(&ctx.ids);
 	TEST_ASSERT_VAL("find other",
-			expr__find_other("FOO + BAR + BAZ + BOZO", "FOO", &other, &num_other, 1) == 0);
-	TEST_ASSERT_VAL("find other", num_other == 3);
-	TEST_ASSERT_VAL("find other", !strcmp(other[0], "BAR"));
-	TEST_ASSERT_VAL("find other", !strcmp(other[1], "BAZ"));
-	TEST_ASSERT_VAL("find other", !strcmp(other[2], "BOZO"));
-	TEST_ASSERT_VAL("find other", other[3] == NULL);
+			expr__find_other("FOO + BAR + BAZ + BOZO", "FOO",
+					 &ctx, 1) == 0);
+	TEST_ASSERT_VAL("find other", hashmap__size(&ctx.ids) == 3);
+	TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "BAR",
+						    (void **)&val_ptr));
+	TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "BAZ",
+						    (void **)&val_ptr));
+	TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "BOZO",
+						    (void **)&val_ptr));
 
+	hashmap__clear(&ctx.ids);
 	TEST_ASSERT_VAL("find other",
-			expr__find_other("EVENT1\\,param\\=?@ + EVENT2\\,param\\=?@", NULL,
-				   &other, &num_other, 3) == 0);
-	TEST_ASSERT_VAL("find other", num_other == 2);
-	TEST_ASSERT_VAL("find other", !strcmp(other[0], "EVENT1,param=3/"));
-	TEST_ASSERT_VAL("find other", !strcmp(other[1], "EVENT2,param=3/"));
-	TEST_ASSERT_VAL("find other", other[2] == NULL);
+			expr__find_other("EVENT1\\,param\\=?@ + EVENT2\\,param\\=?@",
+					 NULL, &ctx, 3) == 0);
+	TEST_ASSERT_VAL("find other", hashmap__size(&ctx.ids) == 2);
+	TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "EVENT1,param=3/",
+						    (void **)&val_ptr));
+	TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "EVENT2,param=3/",
+						    (void **)&val_ptr));
 
-	for (i = 0; i < num_other; i++)
-		zfree(&other[i]);
-	free((void *)other);
+	expr__ctx_clear(&ctx);
 
 	return 0;
 }
diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
index e21f0addcfbb..3de59564deb0 100644
--- a/tools/perf/tests/pmu-events.c
+++ b/tools/perf/tests/pmu-events.c
@@ -433,8 +433,6 @@ static int test_parsing(void)
 	struct pmu_events_map *map;
 	struct pmu_event *pe;
 	int i, j, k;
-	const char **ids;
-	int idnum;
 	int ret = 0;
 	struct expr_parse_ctx ctx;
 	double result;
@@ -446,29 +444,34 @@ static int test_parsing(void)
 			break;
 		j = 0;
 		for (;;) {
+			struct hashmap_entry *cur;
+			size_t bkt;
+
 			pe = &map->table[j++];
 			if (!pe->name && !pe->metric_group && !pe->metric_name)
 				break;
 			if (!pe->metric_expr)
 				continue;
-			if (expr__find_other(pe->metric_expr, NULL,
-						&ids, &idnum, 0) < 0) {
+			expr__ctx_init(&ctx);
+			if (expr__find_other(pe->metric_expr, NULL, &ctx, 0)
+				  < 0) {
 				expr_failure("Parse other failed", map, pe);
 				ret++;
 				continue;
 			}
-			expr__ctx_init(&ctx);
 
 			/*
 			 * Add all ids with a made up value. The value may
 			 * trigger divide by zero when subtracted and so try to
 			 * make them unique.
 			 */
-			for (k = 0; k < idnum; k++)
-				expr__add_id(&ctx, ids[k], k + 1);
+			k = 1;
+			hashmap__for_each_entry((&ctx.ids), cur, bkt)
+				expr__add_id(&ctx, strdup(cur->key), k++);
 
-			for (k = 0; k < idnum; k++) {
-				if (check_parse_id(ids[k], map == cpus_map, pe))
+			hashmap__for_each_entry((&ctx.ids), cur, bkt) {
+				if (check_parse_id(cur->key, map == cpus_map,
+						   pe))
 					ret++;
 			}
 
@@ -476,9 +479,7 @@ static int test_parsing(void)
 				expr_failure("Parse failed", map, pe);
 				ret++;
 			}
-			for (k = 0; k < idnum; k++)
-				zfree(&ids[k]);
-			free(ids);
+			expr__ctx_clear(&ctx);
 		}
 	}
 	/* TODO: fail when not ok */
diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index 8b4ce704a68d..f64ab91c432b 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -4,25 +4,76 @@
 #include "expr.h"
 #include "expr-bison.h"
 #include "expr-flex.h"
+#include <linux/kernel.h>
 
 #ifdef PARSER_DEBUG
 extern int expr_debug;
 #endif
 
+static size_t key_hash(const void *key, void *ctx __maybe_unused)
+{
+	const char *str = (const char *)key;
+	size_t hash = 0;
+
+	while (*str != '\0') {
+		hash *= 31;
+		hash += *str;
+		str++;
+	}
+	return hash;
+}
+
+static bool key_equal(const void *key1, const void *key2,
+		    void *ctx __maybe_unused)
+{
+	return !strcmp((const char *)key1, (const char *)key2);
+}
+
 /* Caller must make sure id is allocated */
-void expr__add_id(struct expr_parse_ctx *ctx, const char *name, double val)
+int expr__add_id(struct expr_parse_ctx *ctx, const char *name, double val)
 {
-	int idx;
+	double *val_ptr = NULL, *old_val = NULL;
+	char *old_key = NULL;
+	int ret;
+
+	if (val != 0.0) {
+		val_ptr = malloc(sizeof(double));
+		if (!val_ptr)
+			return -ENOMEM;
+		*val_ptr = val;
+	}
+	ret = hashmap__set(&ctx->ids, name, val_ptr,
+			   (const void **)&old_key, (void **)&old_val);
+	free(old_key);
+	free(old_val);
+	return ret;
+}
+
+int expr__get_id(struct expr_parse_ctx *ctx, const char *id, double *val_ptr)
+{
+	double *data;
 
-	assert(ctx->num_ids < MAX_PARSE_ID);
-	idx = ctx->num_ids++;
-	ctx->ids[idx].name = name;
-	ctx->ids[idx].val = val;
+	if (!hashmap__find(&ctx->ids, id, (void **)&data))
+		return -1;
+	*val_ptr = (data == NULL) ?  0.0 : *data;
+	return 0;
 }
 
 void expr__ctx_init(struct expr_parse_ctx *ctx)
 {
-	ctx->num_ids = 0;
+	hashmap__init(&ctx->ids, key_hash, key_equal, NULL);
+}
+
+void expr__ctx_clear(struct expr_parse_ctx *ctx)
+{
+	struct hashmap_entry *cur;
+	size_t bkt;
+
+	hashmap__for_each_entry((&ctx->ids), cur, bkt) {
+		free((char *)cur->key);
+		free(cur->value);
+	}
+	hashmap__clear(&ctx->ids);
 }
 
 static int
@@ -56,61 +107,25 @@ __expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
 	return ret;
 }
 
-int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr, int runtime)
+int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
+		const char *expr, int runtime)
 {
 	return __expr__parse(final_val, ctx, expr, EXPR_PARSE, runtime) ? -1 : 0;
 }
 
-static bool
-already_seen(const char *val, const char *one, const char **other,
-	     int num_other)
-{
-	int i;
-
-	if (one && !strcasecmp(one, val))
-		return true;
-	for (i = 0; i < num_other; i++)
-		if (!strcasecmp(other[i], val))
-			return true;
-	return false;
-}
-
-int expr__find_other(const char *expr, const char *one, const char ***other,
-		     int *num_other, int runtime)
+int expr__find_other(const char *expr, const char *one,
+		     struct expr_parse_ctx *ctx, int runtime)
 {
-	int err, i = 0, j = 0;
-	struct expr_parse_ctx ctx;
-
-	expr__ctx_init(&ctx);
-	err = __expr__parse(NULL, &ctx, expr, EXPR_OTHER, runtime);
-	if (err)
-		return -1;
-
-	*other = malloc((ctx.num_ids + 1) * sizeof(char *));
-	if (!*other)
-		return -ENOMEM;
-
-	for (i = 0, j = 0; i < ctx.num_ids; i++) {
-		const char *str = ctx.ids[i].name;
-
-		if (already_seen(str, one, *other, j))
-			continue;
-
-		str = strdup(str);
-		if (!str)
-			goto out;
-		(*other)[j++] = str;
-	}
-	(*other)[j] = NULL;
-
-out:
-	if (i != ctx.num_ids) {
-		while (--j)
-			free((char *) (*other)[i]);
-		free(*other);
-		err = -1;
+	double *old_val = NULL;
+	char *old_key = NULL;
+	int ret = __expr__parse(NULL, ctx, expr, EXPR_OTHER, runtime);
+
+	if (one) {
+		hashmap__delete(&ctx->ids, one,
+				(const void **)&old_key, (void **)&old_val);
+		free(old_key);
+		free(old_val);
 	}
 
-	*num_other = j;
-	return err;
+	return ret;
 }
diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index 40fc452b0f2b..03c961e85e65 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -2,17 +2,10 @@
 #ifndef PARSE_CTX_H
 #define PARSE_CTX_H 1
 
-#define EXPR_MAX_OTHER 64
-#define MAX_PARSE_ID EXPR_MAX_OTHER
-
-struct expr_parse_id {
-	const char *name;
-	double val;
-};
+#include <api/hashmap.h>
 
 struct expr_parse_ctx {
-	int num_ids;
-	struct expr_parse_id ids[MAX_PARSE_ID];
+	struct hashmap ids;
 };
 
 struct expr_scanner_ctx {
@@ -21,9 +14,12 @@ struct expr_scanner_ctx {
 };
 
 void expr__ctx_init(struct expr_parse_ctx *ctx);
-void expr__add_id(struct expr_parse_ctx *ctx, const char *id, double val);
-int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr, int runtime);
-int expr__find_other(const char *expr, const char *one, const char ***other,
-		int *num_other, int runtime);
+void expr__ctx_clear(struct expr_parse_ctx *ctx);
+int expr__add_id(struct expr_parse_ctx *ctx, const char *id, double val);
+int expr__get_id(struct expr_parse_ctx *ctx, const char *id, double *val_ptr);
+int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
+		const char *expr, int runtime);
+int expr__find_other(const char *expr, const char *one,
+		struct expr_parse_ctx *ids, int runtime);
 
 #endif
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index 21e82a1e11a2..ec5a48bf5f34 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -46,19 +46,6 @@ static void expr_error(double *final_val __maybe_unused,
 	pr_debug("%s\n", s);
 }
 
-static int lookup_id(struct expr_parse_ctx *ctx, char *id, double *val)
-{
-	int i;
-
-	for (i = 0; i < ctx->num_ids; i++) {
-		if (!strcasecmp(ctx->ids[i].name, id)) {
-			*val = ctx->ids[i].val;
-			return 0;
-		}
-	}
-	return -1;
-}
-
 %}
 %%
 
@@ -72,12 +59,7 @@ all_other: all_other other
 
 other: ID
 {
-	if (ctx->num_ids + 1 >= EXPR_MAX_OTHER) {
-		pr_err("failed: way too many variables");
-		YYABORT;
-	}
-
-	ctx->ids[ctx->num_ids++].name = $1;
+	expr__add_id(ctx, $1, 0.0);
 }
 |
 MIN | MAX | IF | ELSE | SMT_ON | NUMBER | '|' | '^' | '&' | '-' | '+' | '*' | '/' | '%' | '(' | ')' | ','
@@ -92,7 +74,7 @@ if_expr:
 	;
 
 expr:	  NUMBER
-	| ID			{ if (lookup_id(ctx, $1, &$$) < 0) {
+	| ID			{ if (expr__get_id(ctx, $1, &$$)) {
 					pr_debug("%s not found\n", $1);
 					YYABORT;
 				  }
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index b071df373f8b..37be5a368d6e 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -85,8 +85,7 @@ static void metricgroup__rblist_init(struct rblist *metric_events)
 
 struct egroup {
 	struct list_head nd;
-	int idnum;
-	const char **ids;
+	struct expr_parse_ctx pctx;
 	const char *metric_name;
 	const char *metric_expr;
 	const char *metric_unit;
@@ -94,19 +93,21 @@ struct egroup {
 };
 
 static struct evsel *find_evsel_group(struct evlist *perf_evlist,
-				      const char **ids,
-				      int idnum,
+				      struct expr_parse_ctx *pctx,
 				      struct evsel **metric_events,
 				      bool *evlist_used)
 {
 	struct evsel *ev;
-	int i = 0, j = 0;
 	bool leader_found;
+	const size_t idnum = hashmap__size(&pctx->ids);
+	size_t i = 0;
+	int j = 0;
+	double *val_ptr;
 
 	evlist__for_each_entry (perf_evlist, ev) {
 		if (evlist_used[j++])
 			continue;
-		if (!strcmp(ev->name, ids[i])) {
+		if (hashmap__find(&pctx->ids, ev->name, (void **)&val_ptr)) {
 			if (!metric_events[i])
 				metric_events[i] = ev;
 			i++;
@@ -118,7 +119,8 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
 			memset(metric_events, 0,
 				sizeof(struct evsel *) * idnum);
 
-			if (!strcmp(ev->name, ids[i])) {
+			if (hashmap__find(&pctx->ids, ev->name,
+					  (void **)&val_ptr)) {
 				if (!metric_events[i])
 					metric_events[i] = ev;
 				i++;
@@ -175,19 +177,20 @@ static int metricgroup__setup_events(struct list_head *groups,
 	list_for_each_entry (eg, groups, nd) {
 		struct evsel **metric_events;
 
-		metric_events = calloc(sizeof(void *), eg->idnum + 1);
+		metric_events = calloc(sizeof(void *),
+				hashmap__size(&eg->pctx.ids) + 1);
 		if (!metric_events) {
 			ret = -ENOMEM;
 			break;
 		}
-		evsel = find_evsel_group(perf_evlist, eg->ids, eg->idnum,
-					 metric_events, evlist_used);
+		evsel = find_evsel_group(perf_evlist, &eg->pctx, metric_events,
+					evlist_used);
 		if (!evsel) {
 			pr_debug("Cannot resolve %s: %s\n",
 					eg->metric_name, eg->metric_expr);
 			continue;
 		}
-		for (i = 0; i < eg->idnum; i++)
+		for (i = 0; metric_events[i]; i++)
 			metric_events[i]->collect_stat = true;
 		me = metricgroup__lookup(metric_events_list, evsel, true);
 		if (!me) {
@@ -415,20 +418,20 @@ void metricgroup__print(bool metrics, bool metricgroups, char *filter,
 }
 
 static void metricgroup__add_metric_weak_group(struct strbuf *events,
-					       const char **ids,
-					       int idnum)
+					       struct expr_parse_ctx *ctx)
 {
+	struct hashmap_entry *cur;
+	size_t bkt, i = 0;
 	bool no_group = false;
-	int i;
 
-	for (i = 0; i < idnum; i++) {
-		pr_debug("found event %s\n", ids[i]);
+	hashmap__for_each_entry((&ctx->ids), cur, bkt) {
+		pr_debug("found event %s\n", (const char *)cur->key);
 		/*
 		 * Duration time maps to a software event and can make
 		 * groups not count. Always use it outside a
 		 * group.
 		 */
-		if (!strcmp(ids[i], "duration_time")) {
+		if (!strcmp(cur->key, "duration_time")) {
 			if (i > 0)
 				strbuf_addf(events, "}:W,");
 			strbuf_addf(events, "duration_time");
@@ -437,21 +440,22 @@ static void metricgroup__add_metric_weak_group(struct strbuf *events,
 		}
 		strbuf_addf(events, "%s%s",
 			i == 0 || no_group ? "{" : ",",
-			ids[i]);
+			(const char *)cur->key);
 		no_group = false;
+		i++;
 	}
 	if (!no_group)
 		strbuf_addf(events, "}:W");
 }
 
 static void metricgroup__add_metric_non_group(struct strbuf *events,
-					      const char **ids,
-					      int idnum)
+					      struct expr_parse_ctx *ctx)
 {
-	int i;
+	struct hashmap_entry *cur;
+	size_t bkt;
 
-	for (i = 0; i < idnum; i++)
-		strbuf_addf(events, ",%s", ids[i]);
+	hashmap__for_each_entry((&ctx->ids), cur, bkt)
+		strbuf_addf(events, ",%s", (const char *)cur->key);
 }
 
 static void metricgroup___watchdog_constraint_hint(const char *name, bool foot)
@@ -495,32 +499,32 @@ int __weak arch_get_runtimeparam(void)
 static int __metricgroup__add_metric(struct strbuf *events,
 		struct list_head *group_list, struct pmu_event *pe, int runtime)
 {
-
-	const char **ids;
-	int idnum;
 	struct egroup *eg;
 
-	if (expr__find_other(pe->metric_expr, NULL, &ids, &idnum, runtime) < 0)
-		return -EINVAL;
-
-	if (events->len > 0)
-		strbuf_addf(events, ",");
-
-	if (metricgroup__has_constraint(pe))
-		metricgroup__add_metric_non_group(events, ids, idnum);
-	else
-		metricgroup__add_metric_weak_group(events, ids, idnum);
-
 	eg = malloc(sizeof(*eg));
 	if (!eg)
 		return -ENOMEM;
 
-	eg->ids = ids;
-	eg->idnum = idnum;
+	expr__ctx_init(&eg->pctx);
 	eg->metric_name = pe->metric_name;
 	eg->metric_expr = pe->metric_expr;
 	eg->metric_unit = pe->unit;
 	eg->runtime = runtime;
+
+	if (expr__find_other(pe->metric_expr, NULL, &eg->pctx, runtime) < 0) {
+		expr__ctx_clear(&eg->pctx);
+		free(eg);
+		return -EINVAL;
+	}
+
+	if (events->len > 0)
+		strbuf_addf(events, ",");
+
+	if (metricgroup__has_constraint(pe))
+		metricgroup__add_metric_non_group(events, &eg->pctx);
+	else
+		metricgroup__add_metric_weak_group(events, &eg->pctx);
+
 	list_add_tail(&eg->nd, group_list);
 
 	return 0;
@@ -603,12 +607,9 @@ static int metricgroup__add_metric_list(const char *list, struct strbuf *events,
 static void metricgroup__free_egroups(struct list_head *group_list)
 {
 	struct egroup *eg, *egtmp;
-	int i;
 
 	list_for_each_entry_safe (eg, egtmp, group_list, nd) {
-		for (i = 0; i < eg->idnum; i++)
-			zfree(&eg->ids[i]);
-		zfree(&eg->ids);
+		expr__ctx_clear(&eg->pctx);
 		list_del_init(&eg->nd);
 		free(eg);
 	}
diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 9bd7a8d2a858..c44dc814b377 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -323,35 +323,46 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
 {
 	struct evsel *counter, *leader, **metric_events, *oc;
 	bool found;
-	const char **metric_names;
+	struct expr_parse_ctx ctx;
+	struct hashmap_entry *cur;
+	size_t bkt;
 	int i;
-	int num_metric_names;
 
+	expr__ctx_init(&ctx);
 	evlist__for_each_entry(evsel_list, counter) {
 		bool invalid = false;
 
 		leader = counter->leader;
 		if (!counter->metric_expr)
 			continue;
+
+		expr__ctx_clear(&ctx);
 		metric_events = counter->metric_events;
 		if (!metric_events) {
-			if (expr__find_other(counter->metric_expr, counter->name,
-						&metric_names, &num_metric_names, 1) < 0)
+			if (expr__find_other(counter->metric_expr,
+					     counter->name,
+					     &ctx, 1) < 0)
 				continue;
 
 			metric_events = calloc(sizeof(struct evsel *),
-					       num_metric_names + 1);
-			if (!metric_events)
+					       hashmap__size(&ctx.ids) + 1);
+			if (!metric_events) {
+				expr__ctx_clear(&ctx);
 				return;
+			}
 			counter->metric_events = metric_events;
 		}
 
-		for (i = 0; i < num_metric_names; i++) {
+		i = 0;
+		hashmap__for_each_entry((&ctx.ids), cur, bkt) {
+			const char *metric_name = (const char *)cur->key;
+
 			found = false;
 			if (leader) {
 				/* Search in group */
 				for_each_group_member (oc, leader) {
-					if (!strcasecmp(oc->name, metric_names[i]) &&
+					if (!strcasecmp(oc->name,
+							metric_name) &&
 						!oc->collect_stat) {
 						found = true;
 						break;
@@ -360,7 +371,8 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
 			}
 			if (!found) {
 				/* Search ignoring groups */
-				oc = perf_stat__find_event(evsel_list, metric_names[i]);
+				oc = perf_stat__find_event(evsel_list,
+							   metric_name);
 			}
 			if (!oc) {
 				/* Deduping one is good enough to handle duplicated PMUs. */
@@ -373,27 +385,28 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
 				 * of events. So we ask the user instead to add the missing
 				 * events.
 				 */
-				if (!printed || strcasecmp(printed, metric_names[i])) {
+				if (!printed ||
+				    strcasecmp(printed, metric_name)) {
 					fprintf(stderr,
 						"Add %s event to groups to get metric expression for %s\n",
-						metric_names[i],
+						metric_name,
 						counter->name);
-					printed = strdup(metric_names[i]);
+					printed = strdup(metric_name);
 				}
 				invalid = true;
 				continue;
 			}
-			metric_events[i] = oc;
+			metric_events[i++] = oc;
 			oc->collect_stat = true;
 		}
 		metric_events[i] = NULL;
-		free(metric_names);
 		if (invalid) {
 			free(metric_events);
 			counter->metric_events = NULL;
 			counter->metric_expr = NULL;
 		}
 	}
+	expr__ctx_clear(&ctx);
 }
 
 static double runtime_stat_avg(struct runtime_stat *st,
@@ -738,7 +751,10 @@ static void generic_metric(struct perf_stat_config *config,
 
 	expr__ctx_init(&pctx);
 	/* Must be first id entry */
-	expr__add_id(&pctx, name, avg);
+	n = strdup(name);
+	if (!n)
+		return;
+	expr__add_id(&pctx, n, avg);
 	for (i = 0; metric_events[i]; i++) {
 		struct saved_value *v;
 		struct stats *stats;
@@ -814,8 +830,7 @@ static void generic_metric(struct perf_stat_config *config,
 			     (metric_name ? metric_name : name) : "", 0);
 	}
 
-	for (i = 1; i < pctx.num_ids; i++)
-		zfree(&pctx.ids[i].name);
+	expr__ctx_clear(&pctx);
 }
 
 void perf_stat__print_shadow_stats(struct perf_stat_config *config,
-- 
2.26.2.761.g0e0b3e54be-goog