[PATCH v5 12/50] perf map: Simplify map_ip/unmap_ip and make map size smaller
From: Ian Rogers
Date: Mon Nov 27 2023 - 17:10:56 EST
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@xxxxxxxxxx>
---
tools/perf/util/machine.c | 3 +-
tools/perf/util/map.c | 20 +--------
tools/perf/util/map.h | 83 +++++++++++++++++++-----------------
tools/perf/util/symbol-elf.c | 6 +--
tools/perf/util/symbol.c | 6 +--
5 files changed, 50 insertions(+), 68 deletions(-)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index be3dab9d5253..b6831a1f909d 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1360,8 +1360,7 @@ __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
if (machine->vmlinux_map == NULL)
return -ENOMEM;
- map__set_map_ip(machine->vmlinux_map, identity__map_ip);
- map__set_unmap_ip(machine->vmlinux_map, identity__map_ip);
+ map__set_mapping_type(machine->vmlinux_map, MAPPING_TYPE__IDENTITY);
return maps__insert(machine__kernel_maps(machine), machine->vmlinux_map);
}
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;
-}
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index 1b53d53adc86..3a3b7757da5f 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -16,23 +16,25 @@ struct dso;
struct maps;
struct machine;
+enum mapping_type {
+ /* map__map_ip/map__unmap_ip are given as offsets in the DSO. */
+ MAPPING_TYPE__DSO,
+ /* map__map_ip/map__unmap_ip are just the given ip value. */
+ MAPPING_TYPE__IDENTITY,
+};
+
DECLARE_RC_STRUCT(map) {
u64 start;
u64 end;
- bool erange_warned:1;
- bool priv:1;
- u32 prot;
u64 pgoff;
u64 reloc;
-
- /* ip -> dso rip */
- u64 (*map_ip)(const struct map *, u64);
- /* dso rip -> ip */
- u64 (*unmap_ip)(const struct map *, u64);
-
struct dso *dso;
refcount_t refcnt;
+ u32 prot;
u32 flags;
+ enum mapping_type mapping_type:8;
+ bool erange_warned;
+ bool priv;
};
struct kmap;
@@ -41,38 +43,11 @@ struct kmap *__map__kmap(struct map *map);
struct kmap *map__kmap(struct map *map);
struct maps *map__kmaps(struct map *map);
-/* ip -> dso rip */
-u64 map__dso_map_ip(const struct map *map, u64 ip);
-/* dso rip -> ip */
-u64 map__dso_unmap_ip(const struct map *map, u64 ip);
-/* Returns ip */
-u64 identity__map_ip(const struct map *map __maybe_unused, u64 ip);
-
static inline struct dso *map__dso(const struct map *map)
{
return RC_CHK_ACCESS(map)->dso;
}
-static inline u64 map__map_ip(const struct map *map, u64 ip)
-{
- return RC_CHK_ACCESS(map)->map_ip(map, ip);
-}
-
-static inline u64 map__unmap_ip(const struct map *map, u64 ip)
-{
- return RC_CHK_ACCESS(map)->unmap_ip(map, ip);
-}
-
-static inline void *map__map_ip_ptr(struct map *map)
-{
- return RC_CHK_ACCESS(map)->map_ip;
-}
-
-static inline void* map__unmap_ip_ptr(struct map *map)
-{
- return RC_CHK_ACCESS(map)->unmap_ip;
-}
-
static inline u64 map__start(const struct map *map)
{
return RC_CHK_ACCESS(map)->start;
@@ -123,6 +98,34 @@ static inline size_t map__size(const struct map *map)
return map__end(map) - map__start(map);
}
+/* ip -> dso rip */
+static inline u64 map__dso_map_ip(const struct map *map, u64 ip)
+{
+ return ip - map__start(map) + map__pgoff(map);
+}
+
+/* dso rip -> ip */
+static inline u64 map__dso_unmap_ip(const struct map *map, u64 ip)
+{
+ return ip + map__start(map) - map__pgoff(map);
+}
+
+static inline u64 map__map_ip(const struct map *map, u64 ip)
+{
+ if ((RC_CHK_ACCESS(map)->mapping_type) == MAPPING_TYPE__DSO)
+ return map__dso_map_ip(map, ip);
+ else
+ return ip;
+}
+
+static inline u64 map__unmap_ip(const struct map *map, u64 ip)
+{
+ if ((RC_CHK_ACCESS(map)->mapping_type) == MAPPING_TYPE__DSO)
+ return map__dso_unmap_ip(map, ip);
+ else
+ return ip;
+}
+
/* rip/ip <-> addr suitable for passing to `objdump --start-address=` */
u64 map__rip_2objdump(struct map *map, u64 rip);
@@ -294,13 +297,13 @@ static inline void map__set_dso(struct map *map, struct dso *dso)
RC_CHK_ACCESS(map)->dso = dso;
}
-static inline void map__set_map_ip(struct map *map, u64 (*map_ip)(const struct map *map, u64 ip))
+static inline void map__set_mapping_type(struct map *map, enum mapping_type type)
{
- RC_CHK_ACCESS(map)->map_ip = map_ip;
+ RC_CHK_ACCESS(map)->mapping_type = type;
}
-static inline void map__set_unmap_ip(struct map *map, u64 (*unmap_ip)(const struct map *map, u64 rip))
+static inline enum mapping_type map__mapping_type(struct map *map)
{
- RC_CHK_ACCESS(map)->unmap_ip = unmap_ip;
+ return RC_CHK_ACCESS(map)->mapping_type;
}
#endif /* __PERF_MAP_H */
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 9e7eeaf616b8..4b934ed3bfd1 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -1392,8 +1392,7 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
map__set_start(map, shdr->sh_addr + ref_reloc(kmap));
map__set_end(map, map__start(map) + shdr->sh_size);
map__set_pgoff(map, shdr->sh_offset);
- 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);
/* Ensure maps are correctly ordered */
if (kmaps) {
int err;
@@ -1455,8 +1454,7 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
map__set_end(curr_map, map__start(curr_map) + shdr->sh_size);
map__set_pgoff(curr_map, shdr->sh_offset);
} else {
- map__set_map_ip(curr_map, identity__map_ip);
- map__set_unmap_ip(curr_map, identity__map_ip);
+ map__set_mapping_type(curr_map, MAPPING_TYPE__IDENTITY);
}
curr_dso->symtab_type = dso->symtab_type;
if (maps__insert(kmaps, curr_map))
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 82cc74b9358e..314c0263bf3c 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -956,8 +956,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
return -1;
}
- map__set_map_ip(curr_map, identity__map_ip);
- map__set_unmap_ip(curr_map, identity__map_ip);
+ map__set_mapping_type(curr_map, MAPPING_TYPE__IDENTITY);
if (maps__insert(kmaps, curr_map)) {
dso__put(ndso);
return -1;
@@ -1475,8 +1474,7 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
map__set_start(map, map__start(new_map));
map__set_end(map, map__end(new_map));
map__set_pgoff(map, map__pgoff(new_map));
- map__set_map_ip(map, map__map_ip_ptr(new_map));
- map__set_unmap_ip(map, map__unmap_ip_ptr(new_map));
+ map__set_mapping_type(map, map__mapping_type(new_map));
/* Ensure maps are correctly ordered */
map_ref = map__get(map);
maps__remove(kmaps, map_ref);
--
2.43.0.rc1.413.gea7ed67945-goog