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7728fa0cfa
Move perf_mmap__consume() vrom tools/perf to libperf and export it in the perf/mmap.h header. Move also the needed helpers perf_mmap__write_tail(), perf_mmap__read_head() and perf_mmap__empty(). Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lore.kernel.org/lkml/20191007125344.14268-10-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
93 lines
1.9 KiB
C
93 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <sys/mman.h>
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#include <linux/ring_buffer.h>
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#include <linux/perf_event.h>
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#include <perf/mmap.h>
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#include <internal/mmap.h>
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#include <internal/lib.h>
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#include <linux/kernel.h>
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void perf_mmap__init(struct perf_mmap *map, bool overwrite,
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libperf_unmap_cb_t unmap_cb)
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{
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map->fd = -1;
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map->overwrite = overwrite;
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map->unmap_cb = unmap_cb;
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refcount_set(&map->refcnt, 0);
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}
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size_t perf_mmap__mmap_len(struct perf_mmap *map)
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{
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return map->mask + 1 + page_size;
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}
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int perf_mmap__mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
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int fd, int cpu)
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{
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map->prev = 0;
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map->mask = mp->mask;
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map->base = mmap(NULL, perf_mmap__mmap_len(map), mp->prot,
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MAP_SHARED, fd, 0);
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if (map->base == MAP_FAILED) {
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map->base = NULL;
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return -1;
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}
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map->fd = fd;
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map->cpu = cpu;
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return 0;
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}
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void perf_mmap__munmap(struct perf_mmap *map)
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{
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if (map && map->base != NULL) {
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munmap(map->base, perf_mmap__mmap_len(map));
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map->base = NULL;
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map->fd = -1;
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refcount_set(&map->refcnt, 0);
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}
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if (map && map->unmap_cb)
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map->unmap_cb(map);
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}
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void perf_mmap__get(struct perf_mmap *map)
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{
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refcount_inc(&map->refcnt);
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}
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void perf_mmap__put(struct perf_mmap *map)
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{
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BUG_ON(map->base && refcount_read(&map->refcnt) == 0);
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if (refcount_dec_and_test(&map->refcnt))
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perf_mmap__munmap(map);
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}
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static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
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{
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ring_buffer_write_tail(md->base, tail);
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}
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u64 perf_mmap__read_head(struct perf_mmap *map)
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{
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return ring_buffer_read_head(map->base);
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}
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static bool perf_mmap__empty(struct perf_mmap *map)
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{
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struct perf_event_mmap_page *pc = map->base;
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return perf_mmap__read_head(map) == map->prev && !pc->aux_size;
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}
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void perf_mmap__consume(struct perf_mmap *map)
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{
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if (!map->overwrite) {
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u64 old = map->prev;
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perf_mmap__write_tail(map, old);
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}
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if (refcount_read(&map->refcnt) == 1 && perf_mmap__empty(map))
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perf_mmap__put(map);
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}
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