Commit d1a17759 authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo
Browse files

libperf: Adopt perf_evlist__mmap()/munmap() from tools/perf 



Add libperf's version of perf_evlist__mmap()/munmap() functions and
exporting them in the perf/evlist.h header.

It's the backbone of what we have in perf code. The following changes
will add needed callbacks and then we'll finally switch the perf code to
use libperf's version.

Add mmap/mmap_ovw 'struct perf_mmap' object arrays to hold maps for
libperf's evlist.

Signed-off-by: default avatarJiri 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/20191007125344.14268-14-jolsa@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 151ed5d7

tools/perf/lib/evlist.c

+236 −0
Original line number Diff line number Diff line
@@ -8,13 +8,20 @@ 
#include <internal/evlist.h>

#include <internal/evsel.h>

#include <internal/xyarray.h>

#include <internal/mmap.h>

#include <internal/cpumap.h>

#include <internal/threadmap.h>

#include <internal/xyarray.h>

#include <internal/lib.h>

#include <linux/zalloc.h>

#include <sys/ioctl.h>

#include <stdlib.h>

#include <errno.h>

#include <unistd.h>

#include <fcntl.h>

#include <signal.h>

#include <poll.h>

#include <sys/mman.h>

#include <perf/cpumap.h>

#include <perf/threadmap.h>

#include <api/fd/array.h>
@@ -103,6 +110,10 @@ perf_evlist__next(struct perf_evlist *evlist, struct perf_evsel *prev) 


void perf_evlist__delete(struct perf_evlist *evlist)

{

	if (evlist == NULL)

		return;



	perf_evlist__munmap(evlist);

	free(evlist);

}
@@ -281,3 +292,228 @@ int perf_evlist__poll(struct perf_evlist *evlist, int timeout) 
{

	return fdarray__poll(&evlist->pollfd, timeout);

}



static struct perf_mmap* perf_evlist__alloc_mmap(struct perf_evlist *evlist, bool overwrite)

{

	int i;

	struct perf_mmap *map;



	evlist->nr_mmaps = perf_cpu_map__nr(evlist->cpus);

	if (perf_cpu_map__empty(evlist->cpus))

		evlist->nr_mmaps = perf_thread_map__nr(evlist->threads);



	map = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));

	if (!map)

		return NULL;



	for (i = 0; i < evlist->nr_mmaps; i++) {

		/*

		 * When the perf_mmap() call is made we grab one refcount, plus

		 * one extra to let perf_mmap__consume() get the last

		 * events after all real references (perf_mmap__get()) are

		 * dropped.

		 *

		 * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and

		 * thus does perf_mmap__get() on it.

		 */

		perf_mmap__init(&map[i], overwrite, NULL);

	}



	return map;

}



static void perf_evlist__set_sid_idx(struct perf_evlist *evlist,

				     struct perf_evsel *evsel, int idx, int cpu,

				     int thread)

{

	struct perf_sample_id *sid = SID(evsel, cpu, thread);



	sid->idx = idx;

	if (evlist->cpus && cpu >= 0)

		sid->cpu = evlist->cpus->map[cpu];

	else

		sid->cpu = -1;

	if (!evsel->system_wide && evlist->threads && thread >= 0)

		sid->tid = perf_thread_map__pid(evlist->threads, thread);

	else

		sid->tid = -1;

}



static struct perf_mmap*

perf_evlist__map_get(struct perf_evlist *evlist, bool overwrite, int idx)

{

	struct perf_mmap *map = &evlist->mmap[idx];



	if (overwrite) {

		if (!evlist->mmap_ovw) {

			evlist->mmap_ovw = perf_evlist__alloc_mmap(evlist, true);

			if (!evlist->mmap_ovw)

				return NULL;

		}

		map = &evlist->mmap_ovw[idx];

	}



	return map;

}



#define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y))



static int

mmap_per_evsel(struct perf_evlist *evlist, int idx,

	       struct perf_mmap_param *mp, int cpu_idx,

	       int thread, int *_output, int *_output_overwrite)

{

	int evlist_cpu = perf_cpu_map__cpu(evlist->cpus, cpu_idx);

	struct perf_evsel *evsel;

	int revent;



	perf_evlist__for_each_entry(evlist, evsel) {

		bool overwrite = evsel->attr.write_backward;

		struct perf_mmap *map;

		int *output, fd, cpu;



		if (evsel->system_wide && thread)

			continue;



		cpu = perf_cpu_map__idx(evsel->cpus, evlist_cpu);

		if (cpu == -1)

			continue;



		map = perf_evlist__map_get(evlist, overwrite, idx);

		if (map == NULL)

			return -ENOMEM;



		if (overwrite) {

			mp->prot = PROT_READ;

			output   = _output_overwrite;

		} else {

			mp->prot = PROT_READ | PROT_WRITE;

			output   = _output;

		}



		fd = FD(evsel, cpu, thread);



		if (*output == -1) {

			*output = fd;



			if (perf_mmap__mmap(map, mp, *output, evlist_cpu) < 0)

				return -1;

		} else {

			if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)

				return -1;



			perf_mmap__get(map);

		}



		revent = !overwrite ? POLLIN : 0;



		if (!evsel->system_wide &&

		    perf_evlist__add_pollfd(evlist, fd, map, revent) < 0) {

			perf_mmap__put(map);

			return -1;

		}



		if (evsel->attr.read_format & PERF_FORMAT_ID) {

			if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread,

						   fd) < 0)

				return -1;

			perf_evlist__set_sid_idx(evlist, evsel, idx, cpu,

						 thread);

		}

	}



	return 0;

}



static int

mmap_per_thread(struct perf_evlist *evlist, struct perf_mmap_param *mp)

{

	int thread;

	int nr_threads = perf_thread_map__nr(evlist->threads);



	for (thread = 0; thread < nr_threads; thread++) {

		int output = -1;

		int output_overwrite = -1;



		if (mmap_per_evsel(evlist, thread, mp, 0, thread,

				   &output, &output_overwrite))

			goto out_unmap;

	}



	return 0;



out_unmap:

	perf_evlist__munmap(evlist);

	return -1;

}



static int

mmap_per_cpu(struct perf_evlist *evlist, struct perf_mmap_param *mp)

{

	int nr_threads = perf_thread_map__nr(evlist->threads);

	int nr_cpus    = perf_cpu_map__nr(evlist->cpus);

	int cpu, thread;



	for (cpu = 0; cpu < nr_cpus; cpu++) {

		int output = -1;

		int output_overwrite = -1;



		for (thread = 0; thread < nr_threads; thread++) {

			if (mmap_per_evsel(evlist, cpu, mp, cpu,

					   thread, &output, &output_overwrite))

				goto out_unmap;

		}

	}



	return 0;



out_unmap:

	perf_evlist__munmap(evlist);

	return -1;

}



int perf_evlist__mmap(struct perf_evlist *evlist, int pages)

{

	struct perf_evsel *evsel;

	const struct perf_cpu_map *cpus = evlist->cpus;

	const struct perf_thread_map *threads = evlist->threads;

	struct perf_mmap_param mp;



	if (!evlist->mmap)

		evlist->mmap = perf_evlist__alloc_mmap(evlist, false);

	if (!evlist->mmap)

		return -ENOMEM;



	perf_evlist__for_each_entry(evlist, evsel) {

		if ((evsel->attr.read_format & PERF_FORMAT_ID) &&

		    evsel->sample_id == NULL &&

		    perf_evsel__alloc_id(evsel, perf_cpu_map__nr(cpus), threads->nr) < 0)

			return -ENOMEM;

	}



	evlist->mmap_len = (pages + 1) * page_size;

	mp.mask = evlist->mmap_len - page_size - 1;



	if (perf_cpu_map__empty(cpus))

		return mmap_per_thread(evlist, &mp);



	return mmap_per_cpu(evlist, &mp);

}



void perf_evlist__munmap(struct perf_evlist *evlist)

{

	int i;



	if (evlist->mmap) {

		for (i = 0; i < evlist->nr_mmaps; i++)

			perf_mmap__munmap(&evlist->mmap[i]);

	}



	if (evlist->mmap_ovw) {

		for (i = 0; i < evlist->nr_mmaps; i++)

			perf_mmap__munmap(&evlist->mmap_ovw[i]);

	}



	zfree(&evlist->mmap);

	zfree(&evlist->mmap_ovw);

}

tools/perf/lib/include/internal/evlist.h

+2 −0
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ struct perf_evlist { 
	size_t			 mmap_len;

	struct fdarray		 pollfd;

	struct hlist_head	 heads[PERF_EVLIST__HLIST_SIZE];

	struct perf_mmap	*mmap;

	struct perf_mmap	*mmap_ovw;

};



int perf_evlist__alloc_pollfd(struct perf_evlist *evlist);

tools/perf/lib/include/perf/evlist.h

+3 −0
Original line number Diff line number Diff line
@@ -33,4 +33,7 @@ LIBPERF_API void perf_evlist__set_maps(struct perf_evlist *evlist, 
				       struct perf_thread_map *threads);

LIBPERF_API int perf_evlist__poll(struct perf_evlist *evlist, int timeout);



LIBPERF_API int perf_evlist__mmap(struct perf_evlist *evlist, int pages);

LIBPERF_API void perf_evlist__munmap(struct perf_evlist *evlist);



#endif /* __LIBPERF_EVLIST_H */

tools/perf/lib/libperf.map

+2 −0
Original line number Diff line number Diff line
@@ -40,6 +40,8 @@ LIBPERF_0.0.1 { 
		perf_evlist__next;

		perf_evlist__set_maps;

		perf_evlist__poll;

		perf_evlist__mmap;

		perf_evlist__munmap;

		perf_mmap__consume;

		perf_mmap__read_init;

		perf_mmap__read_done;

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