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Commit c1f9aa0a authored by Jiri Olsa's avatar Jiri Olsa
Browse files

perf tools: Add dso__data_* interface descriptons 



Adding descriptions/explanations for dso__data_* interface
functions.

Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1401892622-30848-10-git-send-email-jolsa@kernel.org


Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
parent a08cae03

tools/perf/util/dso.c

+59 −0
Original line number Original line Diff line number Diff line
@@ -205,6 +205,13 @@ static int __open_dso(struct dso *dso, struct machine *machine) 




static void check_data_close(void);

static void check_data_close(void);





/**

 * dso_close - Open DSO data file

 * @dso: dso object

 *

 * Open @dso's data file descriptor and updates

 * list/count of open DSO objects.

 */

static int open_dso(struct dso *dso, struct machine *machine)

static int open_dso(struct dso *dso, struct machine *machine)

{

{

	int fd = __open_dso(dso, machine);

	int fd = __open_dso(dso, machine);
@@ -231,6 +238,13 @@ static void close_data_fd(struct dso *dso) 
	}

	}

}

}





/**

 * dso_close - Close DSO data file

 * @dso: dso object

 *

 * Close @dso's data file descriptor and updates

 * list/count of open DSO objects.

 */

static void close_dso(struct dso *dso)

static void close_dso(struct dso *dso)

{

{

	close_data_fd(dso);

	close_data_fd(dso);
@@ -276,6 +290,11 @@ static bool may_cache_fd(void) 
	return limit > (rlim_t) dso__data_open_cnt;

	return limit > (rlim_t) dso__data_open_cnt;

}

}





/*

 * Check and close LRU dso if we crossed allowed limit

 * for opened dso file descriptors. The limit is half

 * of the RLIMIT_NOFILE files opened.

*/

static void check_data_close(void)

static void check_data_close(void)

{

{

	bool cache_fd = may_cache_fd();

	bool cache_fd = may_cache_fd();
@@ -284,11 +303,25 @@ static void check_data_close(void) 
		close_first_dso();

		close_first_dso();

}

}





/**

 * dso__data_close - Close DSO data file

 * @dso: dso object

 *

 * External interface to close @dso's data file descriptor.

 */

void dso__data_close(struct dso *dso)

void dso__data_close(struct dso *dso)

{

{

	close_dso(dso);

	close_dso(dso);

}

}





/**

 * dso__data_fd - Get dso's data file descriptor

 * @dso: dso object

 * @machine: machine object

 *

 * External interface to find dso's file, open it and

 * returns file descriptor.

 */

int dso__data_fd(struct dso *dso, struct machine *machine)

int dso__data_fd(struct dso *dso, struct machine *machine)

{

{

	enum dso_binary_type binary_type_data[] = {

	enum dso_binary_type binary_type_data[] = {
@@ -445,6 +478,11 @@ static ssize_t dso_cache_read(struct dso *dso, u64 offset, 
		return dso_cache__read(dso, offset, data, size);

		return dso_cache__read(dso, offset, data, size);

}

}





/*

 * Reads and caches dso data DSO__DATA_CACHE_SIZE size chunks

 * in the rb_tree. Any read to already cached data is served

 * by cached data.

 */

static ssize_t cached_read(struct dso *dso, u64 offset, u8 *data, ssize_t size)

static ssize_t cached_read(struct dso *dso, u64 offset, u8 *data, ssize_t size)

{

{

	ssize_t r = 0;

	ssize_t r = 0;
@@ -504,6 +542,17 @@ static ssize_t data_read_offset(struct dso *dso, u64 offset, 
	return cached_read(dso, offset, data, size);

	return cached_read(dso, offset, data, size);

}

}





/**

 * dso__data_read_offset - Read data from dso file offset

 * @dso: dso object

 * @machine: machine object

 * @offset: file offset

 * @data: buffer to store data

 * @size: size of the @data buffer

 *

 * External interface to read data from dso file offset. Open

 * dso data file and use cached_read to get the data.

 */

ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,

ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,

			      u64 offset, u8 *data, ssize_t size)

			      u64 offset, u8 *data, ssize_t size)

{

{
@@ -513,6 +562,16 @@ ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine, 
	return data_read_offset(dso, offset, data, size);

	return data_read_offset(dso, offset, data, size);

}

}





/**

 * dso__data_read_addr - Read data from dso address

 * @dso: dso object

 * @machine: machine object

 * @add: virtual memory address

 * @data: buffer to store data

 * @size: size of the @data buffer

 *

 * External interface to read data from dso address.

 */

ssize_t dso__data_read_addr(struct dso *dso, struct map *map,

ssize_t dso__data_read_addr(struct dso *dso, struct map *map,

			    struct machine *machine, u64 addr,

			    struct machine *machine, u64 addr,

			    u8 *data, ssize_t size)

			    u8 *data, ssize_t size)

tools/perf/util/dso.h

+38 −0
Original line number Original line Diff line number Diff line
@@ -149,6 +149,44 @@ char dso__symtab_origin(const struct dso *dso); 
int dso__read_binary_type_filename(const struct dso *dso, enum dso_binary_type type,

int dso__read_binary_type_filename(const struct dso *dso, enum dso_binary_type type,

				   char *root_dir, char *filename, size_t size);

				   char *root_dir, char *filename, size_t size);





/*

 * The dso__data_* external interface provides following functions:

 *   dso__data_fd

 *   dso__data_close

 *   dso__data_read_offset

 *   dso__data_read_addr

 *

 * Please refer to the dso.c object code for each function and

 * arguments documentation. Following text tries to explain the

 * dso file descriptor caching.

 *

 * The dso__data* interface allows caching of opened file descriptors

 * to speed up the dso data accesses. The idea is to leave the file

 * descriptor opened ideally for the whole life of the dso object.

 *

 * The current usage of the dso__data_* interface is as follows:

 *

 * Get DSO's fd:

 *   int fd = dso__data_fd(dso, machine);

 *   USE 'fd' SOMEHOW

 *

 * Read DSO's data:

 *   n = dso__data_read_offset(dso_0, &machine, 0, buf, BUFSIZE);

 *   n = dso__data_read_addr(dso_0, &machine, 0, buf, BUFSIZE);

 *

 * Eventually close DSO's fd:

 *   dso__data_close(dso);

 *

 * It is not necessary to close the DSO object data file. Each time new

 * DSO data file is opened, the limit (RLIMIT_NOFILE/2) is checked. Once

 * it is crossed, the oldest opened DSO object is closed.

 *

 * The dso__delete function calls close_dso function to ensure the

 * data file descriptor gets closed/unmapped before the dso object

 * is freed.

 *

 * TODO

*/

int dso__data_fd(struct dso *dso, struct machine *machine);

int dso__data_fd(struct dso *dso, struct machine *machine);

void dso__data_close(struct dso *dso);

void dso__data_close(struct dso *dso);