Commit 237c96b8 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf header: Add ability to keep feature sections 



Many feature sections should not be re-written during perf inject. In
preparation to support that, add callbacks that a tool can use to copy
a feature section from elsewhere. perf inject will use this facility to
copy features sections from the input file.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220520132404.25853-2-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 1634b5a1

tools/perf/util/header.c

+46 −8
Original line number Diff line number Diff line
@@ -3462,9 +3462,22 @@ int perf_header__fprintf_info(struct perf_session *session, FILE *fp, bool full) 
	return 0;

}



struct header_fw {

	struct feat_writer	fw;

	struct feat_fd		*ff;

};



static int feat_writer_cb(struct feat_writer *fw, void *buf, size_t sz)

{

	struct header_fw *h = container_of(fw, struct header_fw, fw);



	return do_write(h->ff, buf, sz);

}



static int do_write_feat(struct feat_fd *ff, int type,

			 struct perf_file_section **p,

			 struct evlist *evlist)

			 struct evlist *evlist,

			 struct feat_copier *fc)

{

	int err;

	int ret = 0;
@@ -3478,6 +3491,22 @@ static int do_write_feat(struct feat_fd *ff, int type, 


		(*p)->offset = lseek(ff->fd, 0, SEEK_CUR);



		/*

		 * Hook to let perf inject copy features sections from the input

		 * file.

		 */

		if (fc && fc->copy) {

			struct header_fw h = {

				.fw.write = feat_writer_cb,

				.ff = ff,

			};



			/* ->copy() returns 0 if the feature was not copied */

			err = fc->copy(fc, type, &h.fw);

		} else {

			err = 0;

		}

		if (!err)

			err = feat_ops[type].write(ff, evlist);

		if (err < 0) {

			pr_debug("failed to write feature %s\n", feat_ops[type].name);
@@ -3494,7 +3523,8 @@ static int do_write_feat(struct feat_fd *ff, int type, 
}



static int perf_header__adds_write(struct perf_header *header,

				   struct evlist *evlist, int fd)

				   struct evlist *evlist, int fd,

				   struct feat_copier *fc)

{

	int nr_sections;

	struct feat_fd ff;
@@ -3523,7 +3553,7 @@ static int perf_header__adds_write(struct perf_header *header, 
	lseek(fd, sec_start + sec_size, SEEK_SET);



	for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) {

		if (do_write_feat(&ff, feat, &p, evlist))

		if (do_write_feat(&ff, feat, &p, evlist, fc))

			perf_header__clear_feat(header, feat);

	}
@@ -3561,9 +3591,10 @@ int perf_header__write_pipe(int fd) 
	return 0;

}



int perf_session__write_header(struct perf_session *session,

static int perf_session__do_write_header(struct perf_session *session,

					 struct evlist *evlist,

			       int fd, bool at_exit)

					 int fd, bool at_exit,

					 struct feat_copier *fc)

{

	struct perf_file_header f_header;

	struct perf_file_attr   f_attr;
@@ -3615,7 +3646,7 @@ int perf_session__write_header(struct perf_session *session, 
	header->feat_offset = header->data_offset + header->data_size;



	if (at_exit) {

		err = perf_header__adds_write(header, evlist, fd);

		err = perf_header__adds_write(header, evlist, fd, fc);

		if (err < 0)

			return err;

	}
@@ -3648,6 +3679,13 @@ int perf_session__write_header(struct perf_session *session, 
	return 0;

}



int perf_session__write_header(struct perf_session *session,

			       struct evlist *evlist,

			       int fd, bool at_exit)

{

	return perf_session__do_write_header(session, evlist, fd, at_exit, NULL);

}



static int perf_header__getbuffer64(struct perf_header *header,

				    int fd, void *buf, size_t size)

{

tools/perf/util/header.h

+10 −0
Original line number Diff line number Diff line
@@ -121,6 +121,16 @@ int perf_session__write_header(struct perf_session *session, 
			       int fd, bool at_exit);

int perf_header__write_pipe(int fd);



/* feat_writer writes a feature section to output */

struct feat_writer {

	int (*write)(struct feat_writer *fw, void *buf, size_t sz);

};



/* feat_copier copies a feature section using feat_writer to output */

struct feat_copier {

	int (*copy)(struct feat_copier *fc, int feat, struct feat_writer *fw);

};



void perf_header__set_feat(struct perf_header *header, int feat);

void perf_header__clear_feat(struct perf_header *header, int feat);

bool perf_header__has_feat(const struct perf_header *header, int feat);