Commit f649ed80 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf dsos: Tidy reference counting and locking 



Move more functionality into dsos.c generally from machine.c, renaming
functions to match their new usage.

The find function is made to always "get" before returning a dso.

Reduce the scope of locks in vdso to match the locking paradigm.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anne Macedo <retpolanne@posteo.net>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Chengen Du <chengen.du@canonical.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Li Dong <lidong@vivo.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Markus Elfring <Markus.Elfring@web.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paran Lee <p4ranlee@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Song Liu <song@kernel.org>
Cc: Sun Haiyong <sunhaiyong@loongson.cn>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Cc: zhaimingbing <zhaimingbing@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20240410064214.2755936-3-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 83acca9f

tools/perf/util/dsos.c

+66 −7
Original line number Diff line number Diff line
@@ -181,7 +181,7 @@ struct dso *__dsos__findnew_link_by_longname_id(struct rb_root *root, struct dso 
			 * at the end of the list of duplicates.

			 */

			if (!dso || (dso == this))

				return this;	/* Find matching dso */

				return dso__get(this);	/* Find matching dso */

			/*

			 * The core kernel DSOs may have duplicated long name.

			 * In this case, the short name should be different.
@@ -253,15 +253,20 @@ static struct dso *__dsos__find_id(struct dsos *dsos, const char *name, struct d 
	if (cmp_short) {

		list_for_each_entry(pos, &dsos->head, node)

			if (__dso__cmp_short_name(name, id, pos) == 0)

				return pos;

				return dso__get(pos);

		return NULL;

	}

	return __dsos__findnew_by_longname_id(&dsos->root, name, id);

}



struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short)

struct dso *dsos__find(struct dsos *dsos, const char *name, bool cmp_short)

{

	return __dsos__find_id(dsos, name, NULL, cmp_short);

	struct dso *res;



	down_read(&dsos->lock);

	res = __dsos__find_id(dsos, name, NULL, cmp_short);

	up_read(&dsos->lock);

	return res;

}



static void dso__set_basename(struct dso *dso)
@@ -303,8 +308,6 @@ static struct dso *__dsos__addnew_id(struct dsos *dsos, const char *name, struct 
	if (dso != NULL) {

		__dsos__add(dsos, dso);

		dso__set_basename(dso);

		/* Put dso here because __dsos_add already got it */

		dso__put(dso);

	}

	return dso;

}
@@ -328,7 +331,7 @@ struct dso *dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id 
{

	struct dso *dso;

	down_write(&dsos->lock);

	dso = dso__get(__dsos__findnew_id(dsos, name, id));

	dso = __dsos__findnew_id(dsos, name, id);

	up_write(&dsos->lock);

	return dso;

}
@@ -374,3 +377,59 @@ int __dsos__hit_all(struct dsos *dsos) 


	return 0;

}



struct dso *dsos__findnew_module_dso(struct dsos *dsos,

				     struct machine *machine,

				     struct kmod_path *m,

				     const char *filename)

{

	struct dso *dso;



	down_write(&dsos->lock);



	dso = __dsos__find_id(dsos, m->name, NULL, /*cmp_short=*/true);

	if (!dso) {

		dso = __dsos__addnew(dsos, m->name);

		if (dso == NULL)

			goto out_unlock;



		dso__set_module_info(dso, m, machine);

		dso__set_long_name(dso, strdup(filename), true);

		dso->kernel = DSO_SPACE__KERNEL;

	}



out_unlock:

	up_write(&dsos->lock);

	return dso;

}



struct dso *dsos__find_kernel_dso(struct dsos *dsos)

{

	struct dso *dso, *res = NULL;



	down_read(&dsos->lock);

	list_for_each_entry(dso, &dsos->head, node) {

		/*

		 * The cpumode passed to is_kernel_module is not the cpumode of

		 * *this* event. If we insist on passing correct cpumode to

		 * is_kernel_module, we should record the cpumode when we adding

		 * this dso to the linked list.

		 *

		 * However we don't really need passing correct cpumode.  We

		 * know the correct cpumode must be kernel mode (if not, we

		 * should not link it onto kernel_dsos list).

		 *

		 * Therefore, we pass PERF_RECORD_MISC_CPUMODE_UNKNOWN.

		 * is_kernel_module() treats it as a kernel cpumode.

		 */

		if (!dso->kernel ||

		    is_kernel_module(dso->long_name,

				     PERF_RECORD_MISC_CPUMODE_UNKNOWN))

			continue;



		res = dso__get(dso);

		break;

	}

	up_read(&dsos->lock);

	return res;

}

tools/perf/util/dsos.h

+8 −1
Original line number Diff line number Diff line
@@ -10,6 +10,8 @@ 


struct dso;

struct dso_id;

struct kmod_path;

struct machine;



/*

 * DSOs are put into both a list for fast iteration and rbtree for fast
@@ -33,7 +35,7 @@ void dsos__exit(struct dsos *dsos); 
void __dsos__add(struct dsos *dsos, struct dso *dso);

void dsos__add(struct dsos *dsos, struct dso *dso);

struct dso *__dsos__addnew(struct dsos *dsos, const char *name);

struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short);

struct dso *dsos__find(struct dsos *dsos, const char *name, bool cmp_short);



struct dso *dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id *id);
@@ -48,4 +50,9 @@ size_t __dsos__fprintf(struct dsos *dsos, FILE *fp); 


int __dsos__hit_all(struct dsos *dsos);



struct dso *dsos__findnew_module_dso(struct dsos *dsos, struct machine *machine,

				     struct kmod_path *m, const char *filename);



struct dso *dsos__find_kernel_dso(struct dsos *dsos);



#endif /* __PERF_DSOS */

tools/perf/util/machine.c

+2 −60
Original line number Diff line number Diff line
@@ -646,31 +646,6 @@ int machine__process_lost_samples_event(struct machine *machine __maybe_unused, 
	return 0;

}



static struct dso *machine__findnew_module_dso(struct machine *machine,

					       struct kmod_path *m,

					       const char *filename)

{

	struct dso *dso;



	down_write(&machine->dsos.lock);



	dso = __dsos__find(&machine->dsos, m->name, true);

	if (!dso) {

		dso = __dsos__addnew(&machine->dsos, m->name);

		if (dso == NULL)

			goto out_unlock;



		dso__set_module_info(dso, m, machine);

		dso__set_long_name(dso, strdup(filename), true);

		dso->kernel = DSO_SPACE__KERNEL;

	}



	dso__get(dso);

out_unlock:

	up_write(&machine->dsos.lock);

	return dso;

}



int machine__process_aux_event(struct machine *machine __maybe_unused,

			       union perf_event *event)

{
@@ -854,7 +829,7 @@ static struct map *machine__addnew_module_map(struct machine *machine, u64 start 
	if (kmod_path__parse_name(&m, filename))

		return NULL;



	dso = machine__findnew_module_dso(machine, &m, filename);

	dso = dsos__findnew_module_dso(&machine->dsos, machine, &m, filename);

	if (dso == NULL)

		goto out;
@@ -1663,40 +1638,7 @@ static int machine__process_kernel_mmap_event(struct machine *machine, 
		 * Should be there already, from the build-id table in

		 * the header.

		 */

		struct dso *kernel = NULL;

		struct dso *dso;



		down_read(&machine->dsos.lock);



		list_for_each_entry(dso, &machine->dsos.head, node) {



			/*

			 * The cpumode passed to is_kernel_module is not the

			 * cpumode of *this* event. If we insist on passing

			 * correct cpumode to is_kernel_module, we should

			 * record the cpumode when we adding this dso to the

			 * linked list.

			 *

			 * However we don't really need passing correct

			 * cpumode.  We know the correct cpumode must be kernel

			 * mode (if not, we should not link it onto kernel_dsos

			 * list).

			 *

			 * Therefore, we pass PERF_RECORD_MISC_CPUMODE_UNKNOWN.

			 * is_kernel_module() treats it as a kernel cpumode.

			 */



			if (!dso->kernel ||

			    is_kernel_module(dso->long_name,

					     PERF_RECORD_MISC_CPUMODE_UNKNOWN))

				continue;





			kernel = dso__get(dso);

			break;

		}



		up_read(&machine->dsos.lock);

		struct dso *kernel = dsos__find_kernel_dso(&machine->dsos);



		if (kernel == NULL)

			kernel = machine__findnew_dso(machine, machine->mmap_name);

tools/perf/util/map.c

+1 −3
Original line number Diff line number Diff line
@@ -196,9 +196,7 @@ struct map *map__new(struct machine *machine, u64 start, u64 len, 
			 * reading the header will have the build ID set and all future mmaps will

			 * have it missing.

			 */

			down_read(&machine->dsos.lock);

			header_bid_dso = __dsos__find(&machine->dsos, filename, false);

			up_read(&machine->dsos.lock);

			header_bid_dso = dsos__find(&machine->dsos, filename, false);

			if (header_bid_dso && header_bid_dso->header_build_id) {

				dso__set_build_id(dso, &header_bid_dso->bid);

				dso->header_build_id = 1;

tools/perf/util/vdso.c

+20 −28
Original line number Diff line number Diff line
@@ -133,8 +133,6 @@ static struct dso *__machine__addnew_vdso(struct machine *machine, const char *s 
	if (dso != NULL) {

		__dsos__add(&machine->dsos, dso);

		dso__set_long_name(dso, long_name, false);

		/* Put dso here because __dsos_add already got it */

		dso__put(dso);

	}



	return dso;
@@ -252,17 +250,15 @@ static struct dso *__machine__findnew_compat(struct machine *machine, 
	const char *file_name;

	struct dso *dso;



	dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);

	dso = dsos__find(&machine->dsos, vdso_file->dso_name, true);

	if (dso)

		goto out;

		return dso;



	file_name = vdso__get_compat_file(vdso_file);

	if (!file_name)

		goto out;

		return NULL;



	dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);

out:

	return dso;

	return __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);

}



static int __machine__findnew_vdso_compat(struct machine *machine,
@@ -308,21 +304,21 @@ static struct dso *machine__find_vdso(struct machine *machine, 
	dso_type = machine__thread_dso_type(machine, thread);

	switch (dso_type) {

	case DSO__TYPE_32BIT:

		dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO32, true);

		dso = dsos__find(&machine->dsos, DSO__NAME_VDSO32, true);

		if (!dso) {

			dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO,

			dso = dsos__find(&machine->dsos, DSO__NAME_VDSO,

					 true);

			if (dso && dso_type != dso__type(dso, machine))

				dso = NULL;

		}

		break;

	case DSO__TYPE_X32BIT:

		dso = __dsos__find(&machine->dsos, DSO__NAME_VDSOX32, true);

		dso = dsos__find(&machine->dsos, DSO__NAME_VDSOX32, true);

		break;

	case DSO__TYPE_64BIT:

	case DSO__TYPE_UNKNOWN:

	default:

		dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);

		dso = dsos__find(&machine->dsos, DSO__NAME_VDSO, true);

		break;

	}
@@ -334,37 +330,33 @@ struct dso *machine__findnew_vdso(struct machine *machine, 
{

	struct vdso_info *vdso_info;

	struct dso *dso = NULL;

	char *file;



	down_write(&machine->dsos.lock);

	if (!machine->vdso_info)

		machine->vdso_info = vdso_info__new();



	vdso_info = machine->vdso_info;

	if (!vdso_info)

		goto out_unlock;

		return NULL;



	dso = machine__find_vdso(machine, thread);

	if (dso)

		goto out_unlock;

		return dso;



#if BITS_PER_LONG == 64

	if (__machine__findnew_vdso_compat(machine, thread, vdso_info, &dso))

		goto out_unlock;

		return dso;

#endif



	dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);

	if (!dso) {

		char *file;

	dso = dsos__find(&machine->dsos, DSO__NAME_VDSO, true);

	if (dso)

		return dso;



	file = get_file(&vdso_info->vdso);

		if (file)

			dso = __machine__addnew_vdso(machine, DSO__NAME_VDSO, file);

	}

	if (!file)

		return NULL;



out_unlock:

	dso__get(dso);

	up_write(&machine->dsos.lock);

	return dso;

	return __machine__addnew_vdso(machine, DSO__NAME_VDSO, file);

}



bool dso__is_vdso(struct dso *dso)