kernel.git/tools/perf/util/evlist.c, branch linux-4.7.y

perf record: Read from backward ring buffer

2016-05-23T21:22:48Z

Introduce rb_find_range() to find start and end position from a backward ring buffer. Signed-off-by: Wang Nan Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1463987628-163563-5-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Add API to pause/resume

2016-05-23T21:22:00Z

perf_evlist__toggle_{pause,resume}() are introduced to pause/resume events in an evlist. Utilize PERF_EVENT_IOC_PAUSE_OUTPUT ioctl. Following commits use them to ensure overwrite ring buffer is paused before reading. Signed-off-by: Wang Nan Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1463987628-163563-2-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang [ Return -1, like all other ioctl() usage in evlist.c, rename 'pause' arg to avoid breaking the build on ubuntu 12.04 and other old systems ] Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Record fd into perf_mmap

2016-05-20T17:56:58Z

Add a fd field into struct perf_mmap so that perf can track the mmap fd. This feature will be used for toggling overwrite ring buffers. Signed-off-by: Wang Nan Cc: He Kuang Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1463762315-155689-3-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Support reading from backward ring buffer

2016-05-09T20:20:53Z

perf_evlist__mmap_read_backward() is introduced for reading backward ring buffer. Since direction for reading such ring buffer is different from the direction kernel writing to it, and since user need to fetch most recent record from it, a perf_evlist__mmap_read_catchup() is introduced to move the reading pointer to the end of the buffer. Signed-off-by: Wang Nan Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1462758471-89706-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Rename variable in perf_mmap__read()

2016-05-06T00:04:04Z

In perf_mmap__read(), give better names to pointers. Original name 'old' and 'head' directly related to pointers in ring buffer control page. For backward ring buffer, the meaning of 'head' point is not 'the first byte of free space', but 'the first byte of the last record'. To reduce confusion, rename 'old' to 'start', 'head' to 'end'. 'start' -> 'end' is the direction the records should be read from. Change parameter order. Change 'overwrite' to 'check_messup'. When reading from 'head', no need to check messup for for backward ring buffer. Signed-off-by: Wang Nan Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1461723563-67451-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Extract perf_mmap__read()

2016-05-06T00:04:03Z

Extract event reader from perf_evlist__mmap_read() to perf__mmap_read(). Future commit will feed it with manually computed 'head' and 'old' pointers. Signed-off-by: Wang Nan Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1461723563-67451-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Enforce ring buffer reading

2016-04-26T13:56:08Z

Don't read broken data after 'head' pointer. Following commits will feed perf_evlist__mmap_read() with some 'head' pointers not maintained by kernel. If 'head' pointer breaks an event, we should avoid reading from the broken event. This can happen in backward ring buffer. For example: old head | | V V +---+------+----------+----+-----+--+ |..E|D....D|C........C|B..B|A....|E.| +---+------+----------+----+-----+--+ 'old' pointer points to the beginning of 'A' and trying read from it, but 'A' has been overwritten. In this case, don't try to read from 'A', simply return NULL. Signed-off-by: Wang Nan Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1461637738-62722-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Expose perf_event_mlock_kb_in_pages() helper

2016-04-15T20:46:31Z

When the user doesn't set --mmap-pages, perf_evlist__mmap() will do it by reading the maximum possible for a non-root user from the /proc/sys/kernel/perf_event_mlock_kb file. Expose that function so that 'perf trace' can, for root users, to bump mmap-pages to a higher value for root, based on the contents of this proc file. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Milian Wolff Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-xay69plylwibpb3l4isrpl1k@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Add (reset,set)_sample_bit methods

2016-04-12T01:18:21Z

For fiddling with sample_type fields in all evsels in an evlist. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Milian Wolff Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-dg6yavctt0hzl2tsgfb43qsr@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Only set filter for tracepoints events

2016-02-26T22:50:01Z

perf_evlist__set_filter() tries to set filter to every evsel linked in the evlist. However, since filters can only be applied to tracepoints, checking type of evsel before calling perf_evsel__set_filter() would be better. Signed-off-by: Wang Nan Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Li Zefan Cc: Peter Zijlstra Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1456479154-136027-6-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo