[v2,03/13] perf dsos: Tidy reference counting and locking

Message ID	20240321160300.1635121-4-irogers@google.com (mailing list archive)
State	Not Applicable
Headers	show Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F262312C53F for <bpf@vger.kernel.org>; Thu, 21 Mar 2024 16:03:14 +0000 (UTC) Date: Thu, 21 Mar 2024 09:02:50 -0700 In-Reply-To: <20240321160300.1635121-1-irogers@google.com> Message-Id: <20240321160300.1635121-4-irogers@google.com> Precedence: bulk Mime-Version: 1.0 References: <20240321160300.1635121-1-irogers@google.com> Subject: [PATCH v2 03/13] perf dsos: Tidy reference counting and locking From: Ian Rogers <irogers@google.com> To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, Arnaldo Carvalho de Melo <acme@kernel.org>, Namhyung Kim <namhyung@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>, Adrian Hunter <adrian.hunter@intel.com>, James Clark <james.clark@arm.com>, Athira Rajeev <atrajeev@linux.vnet.ibm.com>, Colin Ian King <colin.i.king@gmail.com>, " =?utf-8?q?Ahelenia_Ziemia?= =?utf-8?q?=C5=84ska?= " <nabijaczleweli@nabijaczleweli.xyz>, Leo Yan <leo.yan@linux.dev>, Song Liu <song@kernel.org>, Miguel Ojeda <ojeda@kernel.org>, Liam Howlett <liam.howlett@oracle.com>, Ilkka Koskinen <ilkka@os.amperecomputing.com>, Ben Gainey <ben.gainey@arm.com>, K Prateek Nayak <kprateek.nayak@amd.com>, Kan Liang <kan.liang@linux.intel.com>, Yanteng Si <siyanteng@loongson.cn>, Ravi Bangoria <ravi.bangoria@amd.com>, Sun Haiyong <sunhaiyong@loongson.cn>, Changbin Du <changbin.du@huawei.com>, Masami Hiramatsu <mhiramat@kernel.org>, zhaimingbing <zhaimingbing@cmss.chinamobile.com>, Paran Lee <p4ranlee@gmail.com>, Li Dong <lidong@vivo.com>, elfring@users.sourceforge.net, Andi Kleen <ak@linux.intel.com>, Markus Elfring <Markus.Elfring@web.de>, Chengen Du <chengen.du@canonical.com>, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org Content-Type: text/plain; charset="UTF-8"
Series	dso/dsos memory savings and clean up \| expand [v2,00/13] dso/dsos memory savings and clean up [v2,01/13] perf dso: Reorder variables to save space in struct dso [v2,02/13] perf dsos: Attempt to better abstract dsos internals [v2,03/13] perf dsos: Tidy reference counting and locking [v2,04/13] perf dsos: Add dsos__for_each_dso [v2,05/13] perf dso: Move dso functions out of dsos [v2,06/13] perf dsos: Switch more loops to dsos__for_each_dso [v2,07/13] perf dsos: Switch backing storage to array from rbtree/list [v2,08/13] perf dsos: Remove __dsos__addnew [v2,09/13] perf dsos: Remove __dsos__findnew_link_by_longname_id [v2,10/13] perf dsos: Switch hand code to bsearch [v2,11/13] perf dso: Add reference count checking and accessor functions [v2,12/13] perf dso: Reference counting related fixes [v2,13/13] perf dso: Use container_of to avoid a pointer in dso_data

Context	Check	Description
netdev/tree_selection	success	Not a local patch

diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c index e65ef6762bed..d269e09005a7 100644 --- a/tools/perf/util/dsos.c +++ b/tools/perf/util/dsos.c @@ -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; +} diff --git a/tools/perf/util/dsos.h b/tools/perf/util/dsos.h index 1c81ddf07f8f..a7c7f723c5ff 100644 --- a/tools/perf/util/dsos.h +++ b/tools/perf/util/dsos.h @@ -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 */ diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index acd22b589f18..a06b030fba54 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -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); diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index a5d57c201a30..cca871959f87 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -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; diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c index df8963796187..35532dcbff74 100644 --- a/tools/perf/util/vdso.c +++ b/tools/perf/util/vdso.c @@ -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, - true); + 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); - } + file = get_file(&vdso_info->vdso); + 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)

[v2,03/13] perf dsos: Tidy reference counting and locking

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