perf map: Simplify map_ip/unmap_ip and make 'struct map' smaller

When mapping an IP it is either an identity mapping or a DSO relative
mapping, so a single bit is required in the struct to identify
this.

The current code uses function pointers, adding 2 pointers per map and
also pushing the size of a map beyond 1 cache line.

Switch to using a byte to identify the mapping type (as well as priv and
erange_warned), to avoid any masking.

Change struct maps's layout to avoid holes.

Before:
```
struct map {
        u64                        start;                /*     0     8 */
        u64                        end;                  /*     8     8 */
        _Bool                      erange_warned:1;      /*    16: 0  1 */
        _Bool                      priv:1;               /*    16: 1  1 */

        /* XXX 6 bits hole, try to pack */
        /* XXX 3 bytes hole, try to pack */

        u32                        prot;                 /*    20     4 */
        u64                        pgoff;                /*    24     8 */
        u64                        reloc;                /*    32     8 */
        u64                        (*map_ip)(const struct map  *, u64); /*    40     8 */
        u64                        (*unmap_ip)(const struct map  *, u64); /*    48     8 */
        struct dso *               dso;                  /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        refcount_t                 refcnt;               /*    64     4 */
        u32                        flags;                /*    68     4 */

        /* size: 72, cachelines: 2, members: 12 */
        /* sum members: 68, holes: 1, sum holes: 3 */
        /* sum bitfield members: 2 bits, bit holes: 1, sum bit holes: 6 bits */
        /* last cacheline: 8 bytes */
};
```

After:
```
struct map {
        u64                        start;                /*     0     8 */
        u64                        end;                  /*     8     8 */
        u64                        pgoff;                /*    16     8 */
        u64                        reloc;                /*    24     8 */
        struct dso *               dso;                  /*    32     8 */
        refcount_t                 refcnt;               /*    40     4 */
        u32                        prot;                 /*    44     4 */
        u32                        flags;                /*    48     4 */
        enum mapping_type          mapping_type:8;       /*    52: 0  4 */

        /* Bitfield combined with next fields */

        _Bool                      erange_warned;        /*    53     1 */
        _Bool                      priv;                 /*    54     1 */

        /* size: 56, cachelines: 1, members: 11 */
        /* padding: 1 */
        /* last cacheline: 56 bytes */
};
```

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Dmitrii Dolgov <9erthalion6@gmail.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Guilherme Amadio <amadio@gentoo.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Li Dong <lidong@vivo.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Ming Wang <wangming01@loongson.cn>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: Wenyu Liu <liuwenyu7@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20231127220902.1315692-13-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 18 deletions

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index f64b83004421..54c67cb7ecef 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -109,8 +109,7 @@ void map__init(struct map *map, u64 start, u64 end, u64 pgoff, struct dso *dso)
 	map__set_pgoff(map, pgoff);
 	map__set_reloc(map, 0);
 	map__set_dso(map, dso__get(dso));
-	map__set_map_ip(map, map__dso_map_ip);
-	map__set_unmap_ip(map, map__dso_unmap_ip);
+	map__set_mapping_type(map, MAPPING_TYPE__DSO);
 	map__set_erange_warned(map, false);
 	refcount_set(map__refcnt(map), 1);
 }
@@ -172,7 +171,7 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
 		map__init(result, start, start + len, pgoff, dso);
 
 		if (anon || no_dso) {
-			map->map_ip = map->unmap_ip = identity__map_ip;
+			map->mapping_type = MAPPING_TYPE__IDENTITY;
 
 			/*
 			 * Set memory without DSO as loaded. All map__find_*
@@ -630,18 +629,3 @@ struct maps *map__kmaps(struct map *map)
 	}
 	return kmap->kmaps;
 }
-
-u64 map__dso_map_ip(const struct map *map, u64 ip)
-{
-	return ip - map__start(map) + map__pgoff(map);
-}
-
-u64 map__dso_unmap_ip(const struct map *map, u64 ip)
-{
-	return ip + map__start(map) - map__pgoff(map);
-}
-
-u64 identity__map_ip(const struct map *map __maybe_unused, u64 ip)
-{
-	return ip;
-}