From: Arnaldo Carvalho de Melo <a...@redhat.com> To better organize the sources, and we may end up even using it directly, without evlists and evsels.
Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: David Ahern <dsah...@gmail.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Wang Nan <wangn...@huawei.com> Link: http://lkml.kernel.org/n/tip-oiqrm7grflurnnzo2ovfn...@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/Build | 1 + tools/perf/util/evlist.c | 248 ------------------------------------ tools/perf/util/evlist.h | 76 +---------- tools/perf/util/mmap.c | 252 +++++++++++++++++++++++++++++++++++++ tools/perf/util/mmap.h | 94 ++++++++++++++ tools/perf/util/python-ext-sources | 1 + 6 files changed, 349 insertions(+), 323 deletions(-) create mode 100644 tools/perf/util/mmap.c create mode 100644 tools/perf/util/mmap.h diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 369c3163e68c..a3de7916fe63 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -13,6 +13,7 @@ libperf-y += find_bit.o libperf-y += kallsyms.o libperf-y += levenshtein.o libperf-y += llvm-utils.o +libperf-y += mmap.o libperf-y += memswap.o libperf-y += parse-events.o libperf-y += perf_regs.o diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 6a0d7ffbeba0..c6c891e154a6 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -33,9 +33,6 @@ #include <linux/log2.h> #include <linux/err.h> -static void perf_mmap__munmap(struct perf_mmap *map); -static void perf_mmap__put(struct perf_mmap *map); - #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y)) #define SID(e, x, y) xyarray__entry(e->sample_id, x, y) @@ -704,129 +701,6 @@ static int perf_evlist__resume(struct perf_evlist *evlist) return perf_evlist__set_paused(evlist, false); } -/* When check_messup is true, 'end' must points to a good entry */ -static union perf_event * -perf_mmap__read(struct perf_mmap *md, bool check_messup, u64 start, - u64 end, u64 *prev) -{ - unsigned char *data = md->base + page_size; - union perf_event *event = NULL; - int diff = end - start; - - if (check_messup) { - /* - * If we're further behind than half the buffer, there's a chance - * the writer will bite our tail and mess up the samples under us. - * - * If we somehow ended up ahead of the 'end', we got messed up. - * - * In either case, truncate and restart at 'end'. - */ - if (diff > md->mask / 2 || diff < 0) { - fprintf(stderr, "WARNING: failed to keep up with mmap data.\n"); - - /* - * 'end' points to a known good entry, start there. - */ - start = end; - diff = 0; - } - } - - if (diff >= (int)sizeof(event->header)) { - size_t size; - - event = (union perf_event *)&data[start & md->mask]; - size = event->header.size; - - if (size < sizeof(event->header) || diff < (int)size) { - event = NULL; - goto broken_event; - } - - /* - * Event straddles the mmap boundary -- header should always - * be inside due to u64 alignment of output. - */ - if ((start & md->mask) + size != ((start + size) & md->mask)) { - unsigned int offset = start; - unsigned int len = min(sizeof(*event), size), cpy; - void *dst = md->event_copy; - - do { - cpy = min(md->mask + 1 - (offset & md->mask), len); - memcpy(dst, &data[offset & md->mask], cpy); - offset += cpy; - dst += cpy; - len -= cpy; - } while (len); - - event = (union perf_event *) md->event_copy; - } - - start += size; - } - -broken_event: - if (prev) - *prev = start; - - return event; -} - -union perf_event *perf_mmap__read_forward(struct perf_mmap *md, bool check_messup) -{ - u64 head; - u64 old = md->prev; - - /* - * Check if event was unmapped due to a POLLHUP/POLLERR. - */ - if (!refcount_read(&md->refcnt)) - return NULL; - - head = perf_mmap__read_head(md); - - return perf_mmap__read(md, check_messup, old, head, &md->prev); -} - -union perf_event * -perf_mmap__read_backward(struct perf_mmap *md) -{ - u64 head, end; - u64 start = md->prev; - - /* - * Check if event was unmapped due to a POLLHUP/POLLERR. - */ - if (!refcount_read(&md->refcnt)) - return NULL; - - head = perf_mmap__read_head(md); - if (!head) - return NULL; - - /* - * 'head' pointer starts from 0. Kernel minus sizeof(record) form - * it each time when kernel writes to it, so in fact 'head' is - * negative. 'end' pointer is made manually by adding the size of - * the ring buffer to 'head' pointer, means the validate data can - * read is the whole ring buffer. If 'end' is positive, the ring - * buffer has not fully filled, so we must adjust 'end' to 0. - * - * However, since both 'head' and 'end' is unsigned, we can't - * simply compare 'end' against 0. Here we compare '-head' and - * the size of the ring buffer, where -head is the number of bytes - * kernel write to the ring buffer. - */ - if (-head < (u64)(md->mask + 1)) - end = 0; - else - end = head + md->mask + 1; - - return perf_mmap__read(md, false, start, end, &md->prev); -} - union perf_event *perf_evlist__mmap_read_forward(struct perf_evlist *evlist, int idx) { struct perf_mmap *md = &evlist->mmap[idx]; @@ -857,96 +731,16 @@ union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx) return perf_evlist__mmap_read_forward(evlist, idx); } -void perf_mmap__read_catchup(struct perf_mmap *md) -{ - u64 head; - - if (!refcount_read(&md->refcnt)) - return; - - head = perf_mmap__read_head(md); - md->prev = head; -} - void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx) { perf_mmap__read_catchup(&evlist->mmap[idx]); } -static bool perf_mmap__empty(struct perf_mmap *md) -{ - return perf_mmap__read_head(md) == md->prev && !md->auxtrace_mmap.base; -} - -static void perf_mmap__get(struct perf_mmap *map) -{ - refcount_inc(&map->refcnt); -} - -static void perf_mmap__put(struct perf_mmap *md) -{ - BUG_ON(md->base && refcount_read(&md->refcnt) == 0); - - if (refcount_dec_and_test(&md->refcnt)) - perf_mmap__munmap(md); -} - -void perf_mmap__consume(struct perf_mmap *md, bool overwrite) -{ - if (!overwrite) { - u64 old = md->prev; - - perf_mmap__write_tail(md, old); - } - - if (refcount_read(&md->refcnt) == 1 && perf_mmap__empty(md)) - perf_mmap__put(md); -} - void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx) { perf_mmap__consume(&evlist->mmap[idx], evlist->overwrite); } -int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused, - struct auxtrace_mmap_params *mp __maybe_unused, - void *userpg __maybe_unused, - int fd __maybe_unused) -{ - return 0; -} - -void __weak auxtrace_mmap__munmap(struct auxtrace_mmap *mm __maybe_unused) -{ -} - -void __weak auxtrace_mmap_params__init( - struct auxtrace_mmap_params *mp __maybe_unused, - off_t auxtrace_offset __maybe_unused, - unsigned int auxtrace_pages __maybe_unused, - bool auxtrace_overwrite __maybe_unused) -{ -} - -void __weak auxtrace_mmap_params__set_idx( - struct auxtrace_mmap_params *mp __maybe_unused, - struct perf_evlist *evlist __maybe_unused, - int idx __maybe_unused, - bool per_cpu __maybe_unused) -{ -} - -static void perf_mmap__munmap(struct perf_mmap *map) -{ - if (map->base != NULL) { - munmap(map->base, perf_mmap__mmap_len(map)); - map->base = NULL; - map->fd = -1; - refcount_set(&map->refcnt, 0); - } - auxtrace_mmap__munmap(&map->auxtrace_mmap); -} - static void perf_evlist__munmap_nofree(struct perf_evlist *evlist) { int i; @@ -995,48 +789,6 @@ static struct perf_mmap *perf_evlist__alloc_mmap(struct perf_evlist *evlist) return map; } -struct mmap_params { - int prot; - int mask; - struct auxtrace_mmap_params auxtrace_mp; -}; - -static int perf_mmap__mmap(struct perf_mmap *map, - struct mmap_params *mp, int fd) -{ - /* - * The last one will be done at perf_evlist__mmap_consume(), so that we - * make sure we don't prevent tools from consuming every last event in - * the ring buffer. - * - * I.e. we can get the POLLHUP meaning that the fd doesn't exist - * anymore, but the last events for it are still in the ring buffer, - * waiting to be consumed. - * - * Tools can chose to ignore this at their own discretion, but the - * evlist layer can't just drop it when filtering events in - * perf_evlist__filter_pollfd(). - */ - refcount_set(&map->refcnt, 2); - map->prev = 0; - map->mask = mp->mask; - map->base = mmap(NULL, perf_mmap__mmap_len(map), mp->prot, - MAP_SHARED, fd, 0); - if (map->base == MAP_FAILED) { - pr_debug2("failed to mmap perf event ring buffer, error %d\n", - errno); - map->base = NULL; - return -1; - } - map->fd = fd; - - if (auxtrace_mmap__mmap(&map->auxtrace_mmap, - &mp->auxtrace_mp, map->base, fd)) - return -1; - - return 0; -} - static bool perf_evlist__should_poll(struct perf_evlist *evlist __maybe_unused, struct perf_evsel *evsel) diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index b1c14f1fdc27..8c433e95bd9a 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -11,8 +11,8 @@ #include "../perf.h" #include "event.h" #include "evsel.h" +#include "mmap.h" #include "util.h" -#include "auxtrace.h" #include <signal.h> #include <unistd.h> @@ -24,55 +24,6 @@ struct record_opts; #define PERF_EVLIST__HLIST_BITS 8 #define PERF_EVLIST__HLIST_SIZE (1 << PERF_EVLIST__HLIST_BITS) -/** - * struct perf_mmap - perf's ring buffer mmap details - * - * @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this - */ -struct perf_mmap { - void *base; - int mask; - int fd; - refcount_t refcnt; - u64 prev; - struct auxtrace_mmap auxtrace_mmap; - char event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8); -}; - -static inline size_t -perf_mmap__mmap_len(struct perf_mmap *map) -{ - return map->mask + 1 + page_size; -} - -/* - * State machine of bkw_mmap_state: - * - * .________________(forbid)_____________. - * | V - * NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY - * ^ ^ | ^ | - * | |__(forbid)____/ |___(forbid)___/| - * | | - * \_________________(3)_______________/ - * - * NOTREADY : Backward ring buffers are not ready - * RUNNING : Backward ring buffers are recording - * DATA_PENDING : We are required to collect data from backward ring buffers - * EMPTY : We have collected data from backward ring buffers. - * - * (0): Setup backward ring buffer - * (1): Pause ring buffers for reading - * (2): Read from ring buffers - * (3): Resume ring buffers for recording - */ -enum bkw_mmap_state { - BKW_MMAP_NOTREADY, - BKW_MMAP_RUNNING, - BKW_MMAP_DATA_PENDING, - BKW_MMAP_EMPTY, -}; - struct perf_evlist { struct list_head entries; struct hlist_head heads[PERF_EVLIST__HLIST_SIZE]; @@ -177,12 +128,6 @@ struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id); void perf_evlist__toggle_bkw_mmap(struct perf_evlist *evlist, enum bkw_mmap_state state); -union perf_event *perf_mmap__read_forward(struct perf_mmap *map, bool check_messup); -union perf_event *perf_mmap__read_backward(struct perf_mmap *map); - -void perf_mmap__read_catchup(struct perf_mmap *md); -void perf_mmap__consume(struct perf_mmap *md, bool overwrite); - union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx); union perf_event *perf_evlist__mmap_read_forward(struct perf_evlist *evlist, @@ -286,25 +231,6 @@ size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp); int perf_evlist__strerror_open(struct perf_evlist *evlist, int err, char *buf, size_t size); int perf_evlist__strerror_mmap(struct perf_evlist *evlist, int err, char *buf, size_t size); -static inline u64 perf_mmap__read_head(struct perf_mmap *mm) -{ - struct perf_event_mmap_page *pc = mm->base; - u64 head = ACCESS_ONCE(pc->data_head); - rmb(); - return head; -} - -static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail) -{ - struct perf_event_mmap_page *pc = md->base; - - /* - * ensure all reads are done before we write the tail out. - */ - mb(); - pc->data_tail = tail; -} - bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str); void perf_evlist__to_front(struct perf_evlist *evlist, struct perf_evsel *move_evsel); diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c new file mode 100644 index 000000000000..dfc4a007f2c6 --- /dev/null +++ b/tools/perf/util/mmap.c @@ -0,0 +1,252 @@ +/* + * Copyright (C) 2011-2017, Red Hat Inc, Arnaldo Carvalho de Melo <a...@redhat.com> + * + * Parts came from evlist.c builtin-{top,stat,record}.c, see those files for further + * copyright notes. + * + * Released under the GPL v2. (and only v2, not any later version) + */ + +#include <sys/mman.h> +#include "event.h" +#include "mmap.h" +#include "util.h" /* page_size */ + +size_t perf_mmap__mmap_len(struct perf_mmap *map) +{ + return map->mask + 1 + page_size; +} + +/* When check_messup is true, 'end' must points to a good entry */ +static union perf_event *perf_mmap__read(struct perf_mmap *map, bool check_messup, + u64 start, u64 end, u64 *prev) +{ + unsigned char *data = map->base + page_size; + union perf_event *event = NULL; + int diff = end - start; + + if (check_messup) { + /* + * If we're further behind than half the buffer, there's a chance + * the writer will bite our tail and mess up the samples under us. + * + * If we somehow ended up ahead of the 'end', we got messed up. + * + * In either case, truncate and restart at 'end'. + */ + if (diff > map->mask / 2 || diff < 0) { + fprintf(stderr, "WARNING: failed to keep up with mmap data.\n"); + + /* + * 'end' points to a known good entry, start there. + */ + start = end; + diff = 0; + } + } + + if (diff >= (int)sizeof(event->header)) { + size_t size; + + event = (union perf_event *)&data[start & map->mask]; + size = event->header.size; + + if (size < sizeof(event->header) || diff < (int)size) { + event = NULL; + goto broken_event; + } + + /* + * Event straddles the mmap boundary -- header should always + * be inside due to u64 alignment of output. + */ + if ((start & map->mask) + size != ((start + size) & map->mask)) { + unsigned int offset = start; + unsigned int len = min(sizeof(*event), size), cpy; + void *dst = map->event_copy; + + do { + cpy = min(map->mask + 1 - (offset & map->mask), len); + memcpy(dst, &data[offset & map->mask], cpy); + offset += cpy; + dst += cpy; + len -= cpy; + } while (len); + + event = (union perf_event *)map->event_copy; + } + + start += size; + } + +broken_event: + if (prev) + *prev = start; + + return event; +} + +union perf_event *perf_mmap__read_forward(struct perf_mmap *map, bool check_messup) +{ + u64 head; + u64 old = map->prev; + + /* + * Check if event was unmapped due to a POLLHUP/POLLERR. + */ + if (!refcount_read(&map->refcnt)) + return NULL; + + head = perf_mmap__read_head(map); + + return perf_mmap__read(map, check_messup, old, head, &map->prev); +} + +union perf_event *perf_mmap__read_backward(struct perf_mmap *map) +{ + u64 head, end; + u64 start = map->prev; + + /* + * Check if event was unmapped due to a POLLHUP/POLLERR. + */ + if (!refcount_read(&map->refcnt)) + return NULL; + + head = perf_mmap__read_head(map); + if (!head) + return NULL; + + /* + * 'head' pointer starts from 0. Kernel minus sizeof(record) form + * it each time when kernel writes to it, so in fact 'head' is + * negative. 'end' pointer is made manually by adding the size of + * the ring buffer to 'head' pointer, means the validate data can + * read is the whole ring buffer. If 'end' is positive, the ring + * buffer has not fully filled, so we must adjust 'end' to 0. + * + * However, since both 'head' and 'end' is unsigned, we can't + * simply compare 'end' against 0. Here we compare '-head' and + * the size of the ring buffer, where -head is the number of bytes + * kernel write to the ring buffer. + */ + if (-head < (u64)(map->mask + 1)) + end = 0; + else + end = head + map->mask + 1; + + return perf_mmap__read(map, false, start, end, &map->prev); +} + +void perf_mmap__read_catchup(struct perf_mmap *map) +{ + u64 head; + + if (!refcount_read(&map->refcnt)) + return; + + head = perf_mmap__read_head(map); + map->prev = head; +} + +static bool perf_mmap__empty(struct perf_mmap *map) +{ + return perf_mmap__read_head(map) == map->prev && !map->auxtrace_mmap.base; +} + +void perf_mmap__get(struct perf_mmap *map) +{ + refcount_inc(&map->refcnt); +} + +void perf_mmap__put(struct perf_mmap *map) +{ + BUG_ON(map->base && refcount_read(&map->refcnt) == 0); + + if (refcount_dec_and_test(&map->refcnt)) + perf_mmap__munmap(map); +} + +void perf_mmap__consume(struct perf_mmap *map, bool overwrite) +{ + if (!overwrite) { + u64 old = map->prev; + + perf_mmap__write_tail(map, old); + } + + if (refcount_read(&map->refcnt) == 1 && perf_mmap__empty(map)) + perf_mmap__put(map); +} + +int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused, + struct auxtrace_mmap_params *mp __maybe_unused, + void *userpg __maybe_unused, + int fd __maybe_unused) +{ + return 0; +} + +void __weak auxtrace_mmap__munmap(struct auxtrace_mmap *mm __maybe_unused) +{ +} + +void __weak auxtrace_mmap_params__init(struct auxtrace_mmap_params *mp __maybe_unused, + off_t auxtrace_offset __maybe_unused, + unsigned int auxtrace_pages __maybe_unused, + bool auxtrace_overwrite __maybe_unused) +{ +} + +void __weak auxtrace_mmap_params__set_idx(struct auxtrace_mmap_params *mp __maybe_unused, + struct perf_evlist *evlist __maybe_unused, + int idx __maybe_unused, + bool per_cpu __maybe_unused) +{ +} + +void perf_mmap__munmap(struct perf_mmap *map) +{ + if (map->base != NULL) { + munmap(map->base, perf_mmap__mmap_len(map)); + map->base = NULL; + map->fd = -1; + refcount_set(&map->refcnt, 0); + } + auxtrace_mmap__munmap(&map->auxtrace_mmap); +} + +int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd) +{ + /* + * The last one will be done at perf_evlist__mmap_consume(), so that we + * make sure we don't prevent tools from consuming every last event in + * the ring buffer. + * + * I.e. we can get the POLLHUP meaning that the fd doesn't exist + * anymore, but the last events for it are still in the ring buffer, + * waiting to be consumed. + * + * Tools can chose to ignore this at their own discretion, but the + * evlist layer can't just drop it when filtering events in + * perf_evlist__filter_pollfd(). + */ + refcount_set(&map->refcnt, 2); + map->prev = 0; + map->mask = mp->mask; + map->base = mmap(NULL, perf_mmap__mmap_len(map), mp->prot, + MAP_SHARED, fd, 0); + if (map->base == MAP_FAILED) { + pr_debug2("failed to mmap perf event ring buffer, error %d\n", + errno); + map->base = NULL; + return -1; + } + map->fd = fd; + + if (auxtrace_mmap__mmap(&map->auxtrace_mmap, + &mp->auxtrace_mp, map->base, fd)) + return -1; + + return 0; +} diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h new file mode 100644 index 000000000000..f37ff45c8ec1 --- /dev/null +++ b/tools/perf/util/mmap.h @@ -0,0 +1,94 @@ +#ifndef __PERF_MMAP_H +#define __PERF_MMAP_H 1 + +#include <linux/compiler.h> +#include <linux/refcount.h> +#include <linux/types.h> +#include <asm/barrier.h> +#include <stdbool.h> +#include "auxtrace.h" +#include "event.h" + +/** + * struct perf_mmap - perf's ring buffer mmap details + * + * @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this + */ +struct perf_mmap { + void *base; + int mask; + int fd; + refcount_t refcnt; + u64 prev; + struct auxtrace_mmap auxtrace_mmap; + char event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8); +}; + +/* + * State machine of bkw_mmap_state: + * + * .________________(forbid)_____________. + * | V + * NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY + * ^ ^ | ^ | + * | |__(forbid)____/ |___(forbid)___/| + * | | + * \_________________(3)_______________/ + * + * NOTREADY : Backward ring buffers are not ready + * RUNNING : Backward ring buffers are recording + * DATA_PENDING : We are required to collect data from backward ring buffers + * EMPTY : We have collected data from backward ring buffers. + * + * (0): Setup backward ring buffer + * (1): Pause ring buffers for reading + * (2): Read from ring buffers + * (3): Resume ring buffers for recording + */ +enum bkw_mmap_state { + BKW_MMAP_NOTREADY, + BKW_MMAP_RUNNING, + BKW_MMAP_DATA_PENDING, + BKW_MMAP_EMPTY, +}; + +struct mmap_params { + int prot, mask; + struct auxtrace_mmap_params auxtrace_mp; +}; + +int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd); +void perf_mmap__munmap(struct perf_mmap *map); + +void perf_mmap__get(struct perf_mmap *map); +void perf_mmap__put(struct perf_mmap *map); + +void perf_mmap__consume(struct perf_mmap *map, bool overwrite); + +void perf_mmap__read_catchup(struct perf_mmap *md); + +static inline u64 perf_mmap__read_head(struct perf_mmap *mm) +{ + struct perf_event_mmap_page *pc = mm->base; + u64 head = ACCESS_ONCE(pc->data_head); + rmb(); + return head; +} + +static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail) +{ + struct perf_event_mmap_page *pc = md->base; + + /* + * ensure all reads are done before we write the tail out. + */ + mb(); + pc->data_tail = tail; +} + +union perf_event *perf_mmap__read_forward(struct perf_mmap *map, bool check_messup); +union perf_event *perf_mmap__read_backward(struct perf_mmap *map); + +size_t perf_mmap__mmap_len(struct perf_mmap *map); + +#endif /*__PERF_MMAP_H */ diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources index e66dc495809a..b4f2f06722a7 100644 --- a/tools/perf/util/python-ext-sources +++ b/tools/perf/util/python-ext-sources @@ -10,6 +10,7 @@ util/ctype.c util/evlist.c util/evsel.c util/cpumap.c +util/mmap.c util/namespaces.c ../lib/bitmap.c ../lib/find_bit.c -- 2.13.6
