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AJvYcCVlzIabJdmazRGDKMR+dc2DQAtmrfowuVQCQiZGXfCZnubZ6/v7fwHofsNwVIPiC2xa/BlMQyNJPv6zpwfCU56NJw81 X-Gm-Message-State: AOJu0YwafCiZOcfnxPZzvRqabOU9EYDM+a94mM0WC60TQ3EJmXFyrj3j tyPYz5USEyb26kvGkDMG94vjvsImXBEi0fi436bErnpzavnlvJU2eZiashrm8v3fkZmZY7dpkBy ZHcNCZg== X-Google-Smtp-Source: AGHT+IEFHHZasnj2mYopC5f1pnrpW06sEqfw8QoBxN42dadZ7d85PrSB5YSFIf5ai0Iv9zBrAL8mxN9ZdExS X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:18c5:d9c6:d1d6:a3ec]) (user=irogers job=sendgmr) by 2002:a05:690c:997:b0:617:cced:e96f with SMTP id ce23-20020a05690c099700b00617ccede96fmr379375ywb.8.1712731345532; Tue, 09 Apr 2024 23:42:25 -0700 (PDT) Date: Tue, 9 Apr 2024 23:42:04 -0700 In-Reply-To: <20240410064214.2755936-1-irogers@google.com> Message-Id: <20240410064214.2755936-3-irogers@google.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240410064214.2755936-1-irogers@google.com> X-Mailer: git-send-email 2.44.0.478.gd926399ef9-goog Subject: [PATCH v3 02/12] perf dsos: Tidy reference counting and locking From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , James Clark , Athira Rajeev , Colin Ian King , Leo Yan , Song Liu , Ilkka Koskinen , Ben Gainey , K Prateek Nayak , Yanteng Si , Yicong Yang , Sun Haiyong , Ravi Bangoria , Anne Macedo , Changbin Du , Andi Kleen , Thomas Richter , Masami Hiramatsu , zhaimingbing , Li Dong , Paran Lee , elfring@users.sourceforge.net, Markus Elfring , Yang Jihong , Chengen Du , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org Move more functionality into dsos.c generally from machine, 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: Ian Rogers --- tools/perf/util/dsos.c | 73 +++++++++++++++++++++++++++++++++++---- tools/perf/util/dsos.h | 9 ++++- tools/perf/util/machine.c | 62 ++------------------------------- tools/perf/util/map.c | 4 +-- tools/perf/util/vdso.c | 48 +++++++++++-------------- 5 files changed, 97 insertions(+), 99 deletions(-) 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 dc8d5e410535..42e49b6ce5a7 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)