kernel/tools/perf/util/map_groups.h, branch linux-rolling-stable

perf maps: Rename map_groups.h to maps.h

2019-11-26T14:07:46Z

One more step in the merge of 'struct maps' with 'struct map_groups'. Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-9ibtn3vua76f934t7woyf26w@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Rename 'mg' variables to 'maps'

2019-11-26T14:07:46Z

Continuing the merge of 'struct maps' with 'struct map_groups'. Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-z8d14wrw393a0fbvmnk1bqd9@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Merge 'struct maps' with 'struct map_groups'

2019-11-26T14:07:46Z

And pick the shortest name: 'struct maps'. The split existed because we used to have two groups of maps, one for functions and one for variables, but that only complicated things, sometimes we needed to figure out what was at some address and then had to first try it on the functions group and if that failed, fall back to the variables one. That split is long gone, so for quite a while we had only one struct maps per struct map_groups, simplify things by combining those structs. First patch is the minimum needed to merge both, follow up patches will rename 'thread->mg' to 'thread->maps', etc. Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-hom6639ro7020o708trhxh59@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf map: Remove unused functions

2019-11-26T14:07:46Z

At some point those stopped being used, prune them. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-p2k98mj3ff2uk1z95sbl5r6e@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf map_groups: Auto sort maps by name, if needed

2019-11-18T16:01:58Z

There are still lots of lookups by name, even if just when loading vmlinux, till that code is studied to figure out if its possible to do away with those map lookup by names, provide a way to sort it using libc's qsort/bsearch. Doing it at the first lookup defers the sorting a bit, and as the code stands now, is never done for user maps, just for the kernel ones. # perf probe -l # perf probe -x ~/bin/perf -L __map_groups__find_by_name <__map_groups__find_by_name@/home/acme/git/perf/tools/perf/util/symbol.c:0> 0 static struct map *__map_groups__find_by_name(struct map_groups *mg, const char *name) 1 { struct map **mapp; 4 if (mg->maps_by_name == NULL && 5 map__groups__sort_by_name_from_rbtree(mg)) 6 return NULL; 8 mapp = bsearch(name, mg->maps_by_name, mg->nr_maps, sizeof(*mapp), map__strcmp_name); 9 if (mapp) 10 return *mapp; 11 return NULL; 12 } struct map *map_groups__find_by_name(struct map_groups *mg, const char *name) { # perf probe -x ~/bin/perf 'found=__map_groups__find_by_name:10 name:string' Added new event: probe_perf:found (on __map_groups__find_by_name:10 in /home/acme/bin/perf with name:string) You can now use it in all perf tools, such as: perf record -e probe_perf:found -aR sleep 1 # # perf probe -x ~/bin/perf -L map_groups__find_by_name 0 struct map *map_groups__find_by_name(struct map_groups *mg, const char *name) 1 { 2 struct maps *maps = &mg->maps; struct map *map; 5 down_read(&maps->lock); 7 if (mg->last_search_by_name && strcmp(mg->last_search_by_name->dso->short_name, name) == 0) { 8 map = mg->last_search_by_name; 9 goto out_unlock; } /* * If we have mg->maps_by_name, then the name isn't in the rbtree, * as mg->maps_by_name mirrors the rbtree when lookups by name are * made. */ 16 map = __map_groups__find_by_name(mg, name); 17 if (map || mg->maps_by_name != NULL) 18 goto out_unlock; /* Fallback to traversing the rbtree... */ 21 maps__for_each_entry(maps, map) 22 if (strcmp(map->dso->short_name, name) == 0) { 23 mg->last_search_by_name = map; 24 goto out_unlock; } 27 map = NULL; out_unlock: 30 up_read(&maps->lock); 31 return map; 32 } int dso__load_vmlinux(struct dso *dso, struct map *map, const char *vmlinux, bool vmlinux_allocated) # perf probe -x ~/bin/perf 'fallback=map_groups__find_by_name:21 name:string' Added new events: probe_perf:fallback (on map_groups__find_by_name:21 in /home/acme/bin/perf with name:string) probe_perf:fallback_1 (on map_groups__find_by_name:21 in /home/acme/bin/perf with name:string) You can now use it in all perf tools, such as: perf record -e probe_perf:fallback_1 -aR sleep 1 # # perf probe -l probe_perf:fallback (on map_groups__find_by_name:21@util/symbol.c in /home/acme/bin/perf with name_string) probe_perf:fallback_1 (on map_groups__find_by_name:21@util/symbol.c in /home/acme/bin/perf with name_string) probe_perf:found (on __map_groups__find_by_name:10@util/symbol.c in /home/acme/bin/perf with name_string) # # perf stat -e probe_perf:* Now run 'perf top' in another term and then, after a while, stop 'perf stat': Furthermore, if we ask for interval printing, we can see that that is done just at the start of the workload: # perf stat -I1000 -e probe_perf:* # time counts unit events 1.000319513 0 probe_perf:found 1.000319513 0 probe_perf:fallback_1 1.000319513 0 probe_perf:fallback 2.001868092 23,251 probe_perf:found 2.001868092 0 probe_perf:fallback_1 2.001868092 0 probe_perf:fallback 3.002901597 0 probe_perf:found 3.002901597 0 probe_perf:fallback_1 3.002901597 0 probe_perf:fallback 4.003358591 0 probe_perf:found 4.003358591 0 probe_perf:fallback_1 4.003358591 0 probe_perf:fallback ^C # Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-c5lmbyr14x448rcfii7y6t3k@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf map_groups: Add a front end cache for map lookups by name

2019-11-18T14:21:32Z

Lets see if it helps: First look at the probeable lines for the function that does lookups by name in a map_groups struct: # perf probe -x ~/bin/perf -L map_groups__find_by_name 0 struct map *map_groups__find_by_name(struct map_groups *mg, const char *name) 1 { 2 struct maps *maps = &mg->maps; struct map *map; 5 down_read(&maps->lock); 7 if (mg->last_search_by_name && strcmp(mg->last_search_by_name->dso->short_name, name) == 0) { 8 map = mg->last_search_by_name; 9 goto out_unlock; } 12 maps__for_each_entry(maps, map) 13 if (strcmp(map->dso->short_name, name) == 0) { 14 mg->last_search_by_name = map; 15 goto out_unlock; } 18 map = NULL; out_unlock: 21 up_read(&maps->lock); 22 return map; 23 } int dso__load_vmlinux(struct dso *dso, struct map *map, const char *vmlinux, bool vmlinux_allocated) # Now add a probe to the place where we reuse the last search: # perf probe -x ~/bin/perf map_groups__find_by_name:8 Added new event: probe_perf:map_groups__find_by_name (on map_groups__find_by_name:8 in /home/acme/bin/perf) You can now use it in all perf tools, such as: perf record -e probe_perf:map_groups__find_by_name -aR sleep 1 # Now lets do a system wide 'perf stat' counting those events: # perf stat -e probe_perf:* Leave it running and lets do a 'perf top', then, after a while, stop the 'perf stat': # perf stat -e probe_perf:* ^C Performance counter stats for 'system wide': 3,603 probe_perf:map_groups__find_by_name 44.565253139 seconds time elapsed # yeah, good to have. Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-tcz37g3nxv3tvxw3q90vga3p@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Do not use an rbtree to sort by map name

2019-11-18T14:19:51Z

This is only used for the kernel maps, shave 24 bytes out 'struct map' and just traverse the existing per ip rbtree to look for maps by name, use a front end cache to reuse the last search if its the same name. After this 'struct map' is down to just two cachelines: $ pahole -C map ~/bin/perf struct map { union { struct rb_node rb_node __attribute__((__aligned__(8))); /* 0 24 */ struct list_head node; /* 0 16 */ } __attribute__((__aligned__(8))); /* 0 24 */ u64 start; /* 24 8 */ u64 end; /* 32 8 */ _Bool erange_warned; /* 40 1 */ /* XXX 3 bytes hole, try to pack */ u32 priv; /* 44 4 */ u32 prot; /* 48 4 */ u32 flags; /* 52 4 */ u64 pgoff; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ u64 reloc; /* 64 8 */ u32 maj; /* 72 4 */ u32 min; /* 76 4 */ u64 ino; /* 80 8 */ u64 ino_generation; /* 88 8 */ u64 (*map_ip)(struct map *, u64); /* 96 8 */ u64 (*unmap_ip)(struct map *, u64); /* 104 8 */ struct dso * dso; /* 112 8 */ refcount_t refcnt; /* 120 4 */ /* size: 128, cachelines: 2, members: 17 */ /* sum members: 121, holes: 1, sum holes: 3 */ /* padding: 4 */ /* forced alignments: 1 */ } __attribute__((__aligned__(8))); $ Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-bvr8fqfgzxtgnhnwt5sssx5g@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Purge the entries from maps->names in mapspurge()

2019-11-13T19:06:28Z

No need to iterate via the ->names rbtree, as all the entries there as in maps->entries as well, reuse __maps__purge() for that. Doing it this way we can kill maps__for_each_entry_by_name(), maps__for_each_entry_by_name_safe(), maps__{first,next}_by_name(). Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-ps0nrio8pydyo23rr2s696ue@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf map_groups: Pass the object to map_groups__find_ams()

2019-11-12T11:20:53Z

We were just passing a map to look for and reuse its map->groups member, but the idea is that this is going away, as a map can be in multiple rb_trees when being reused via a map_node, so do as all the other map_groups methods and pass as its first arg the object being operated on. Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-nmi2pbggqloogwl6vxrvex5a@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf map_groups: Introduce for_each_entry() and for_each_entry_safe() iterators

2019-11-06T18:49:39Z

To reduce boilerplate, providing a more compact form to iterate over the maps in a map_group. Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-gc3go6fmdn30twusg91t2q56@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

kernel/tools/perf/util/map_groups.h, branch linux-rolling-stable

perf maps: Rename map_groups.h to maps.h

perf maps: Rename 'mg' variables to 'maps'

perf maps: Merge 'struct maps' with 'struct map_groups'

perf map: Remove unused functions

perf map_groups: Auto sort maps by name, if needed

perf map_groups: Add a front end cache for map lookups by name

perf maps: Do not use an rbtree to sort by map name

perf maps: Purge the entries from maps->names in __maps__purge()

perf map_groups: Pass the object to map_groups__find_ams()

perf map_groups: Introduce for_each_entry() and for_each_entry_safe() iterators

perf maps: Purge the entries from maps->names in mapspurge()