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

Browse source 
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>
This commit is contained in:
Ian Rogers 2023-11-27 14:08:24 -08:00 committed by Arnaldo Carvalho de Melo
parent 407a3898d7
commit 9fa688ea34
5 changed files with 50 additions and 68 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
tools/perf/util/machine.c
View file

@ -1359,8 +1359,7 @@ __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);
}

20
tools/perf/util/map.c
View file

@ -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;
}

83
tools/perf/util/map.h
View file

@ -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 */

6
tools/perf/util/symbol-elf.c
View file

@ -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))

6
tools/perf/util/symbol.c
View file

@ -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);