forked from luck/tmp_suning_uos_patched
7bb4597295
Except for 'perf record', the other perf tools read events one by one
from the ring buffer using perf_mmap__read_forward(). But it only
supports non-overwrite mode.
Introduce perf_mmap__read_event() to support both non-overwrite and
overwrite mode.
Usage:
perf_mmap__read_init()
while(event = perf_mmap__read_event()) {
//process the event
perf_mmap__consume()
}
perf_mmap__read_done()
It cannot use perf_mmap__read_backward(). Because it always reads the
stale buffer which is already processed. Furthermore, the forward and
backward concepts have been removed. The perf_mmap__read_backward() will
be replaced and discarded later.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1516310792-208685-9-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
105 lines
2.9 KiB
C
105 lines
2.9 KiB
C
#ifndef __PERF_MMAP_H
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#define __PERF_MMAP_H 1
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#include <linux/compiler.h>
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#include <linux/refcount.h>
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#include <linux/types.h>
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#include <asm/barrier.h>
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#include <stdbool.h>
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#include "auxtrace.h"
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#include "event.h"
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/**
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* struct perf_mmap - perf's ring buffer mmap details
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*
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* @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this
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*/
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struct perf_mmap {
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void *base;
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int mask;
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int fd;
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refcount_t refcnt;
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u64 prev;
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struct auxtrace_mmap auxtrace_mmap;
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char event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
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};
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/*
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* State machine of bkw_mmap_state:
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*
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* .________________(forbid)_____________.
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* | V
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* NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY
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* ^ ^ | ^ |
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* | |__(forbid)____/ |___(forbid)___/|
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* | |
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* \_________________(3)_______________/
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*
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* NOTREADY : Backward ring buffers are not ready
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* RUNNING : Backward ring buffers are recording
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* DATA_PENDING : We are required to collect data from backward ring buffers
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* EMPTY : We have collected data from backward ring buffers.
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*
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* (0): Setup backward ring buffer
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* (1): Pause ring buffers for reading
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* (2): Read from ring buffers
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* (3): Resume ring buffers for recording
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*/
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enum bkw_mmap_state {
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BKW_MMAP_NOTREADY,
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BKW_MMAP_RUNNING,
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BKW_MMAP_DATA_PENDING,
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BKW_MMAP_EMPTY,
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};
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struct mmap_params {
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int prot, mask;
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struct auxtrace_mmap_params auxtrace_mp;
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};
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int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd);
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void perf_mmap__munmap(struct perf_mmap *map);
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void perf_mmap__get(struct perf_mmap *map);
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void perf_mmap__put(struct perf_mmap *map);
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void perf_mmap__consume(struct perf_mmap *map, bool overwrite);
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void perf_mmap__read_catchup(struct perf_mmap *md);
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static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
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{
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struct perf_event_mmap_page *pc = mm->base;
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u64 head = READ_ONCE(pc->data_head);
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rmb();
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return head;
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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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struct perf_event_mmap_page *pc = md->base;
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/*
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* ensure all reads are done before we write the tail out.
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*/
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mb();
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pc->data_tail = tail;
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}
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union perf_event *perf_mmap__read_forward(struct perf_mmap *map);
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union perf_event *perf_mmap__read_backward(struct perf_mmap *map);
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union perf_event *perf_mmap__read_event(struct perf_mmap *map,
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bool overwrite,
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u64 *startp, u64 end);
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int perf_mmap__push(struct perf_mmap *md, bool backward,
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void *to, int push(void *to, void *buf, size_t size));
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size_t perf_mmap__mmap_len(struct perf_mmap *map);
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int perf_mmap__read_init(struct perf_mmap *md, bool overwrite,
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u64 *startp, u64 *endp);
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void perf_mmap__read_done(struct perf_mmap *map);
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#endif /*__PERF_MMAP_H */
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