From patchwork Fri Feb 3 02:13:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namhyung Kim X-Patchwork-Id: 13126924 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85895C6379F for ; Fri, 3 Feb 2023 02:13:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229699AbjBCCNd (ORCPT ); Thu, 2 Feb 2023 21:13:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231465AbjBCCNb (ORCPT ); Thu, 2 Feb 2023 21:13:31 -0500 Received: from mail-pj1-x1036.google.com (mail-pj1-x1036.google.com [IPv6:2607:f8b0:4864:20::1036]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C70C21290; Thu, 2 Feb 2023 18:13:30 -0800 (PST) Received: by mail-pj1-x1036.google.com with SMTP id t12-20020a17090aae0c00b00229f4cff534so6918907pjq.1; Thu, 02 Feb 2023 18:13:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=vVb6/wY5BO86ABIxc8pLAp0Fww2Vgk9VT30AEyLAIxo=; b=KwzAhqGoIxk/QgLhdRBq68ZGuM3GsY8mmRu3zZkE72wvSJgiW7HVIR5DLr5bsVNXgS l3/v0/PUF7kihPB+DkLf0oKJRwoBOxI4Fqmfkjre1f59fjOjkn6QnDbCxWXnulFYa53t IOHkq0NU4tX7T0pZFPih49XcawI0iwRtRsmSugKjBE6eH3kHINggzOOevDM41o9p5pbX FCSHWoFW9AcwrFJbZBHonkbmIhRZexqklRx5BJpdc99pHimcQBpcUUD7Z9P3j+nv9c/V bc7ToLj1fzUA0kHMOcVaVxiK1oW+WV1yINawg3USoBG/2/Ud7geReHVJEtzRO4o9sIa0 xsTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=vVb6/wY5BO86ABIxc8pLAp0Fww2Vgk9VT30AEyLAIxo=; b=oNrYOPLqZJ2ZeMHkGae1XtXR57AK8rQ6TAT+MWFufxaWkwT18MOvsV5Mveervdx6pi 4rk2H4MmaOwC+nYDiIrZUH1dIekdXt2DzWPR5CWTMDZ0HD6f2uKsJ8Q41O6eG5oqQtcU JNwyv8Ael6X1Mk0jI385OaV2S0RD8TO8GrW88uUsqIBEImD/uJVkxrTqP73gNenzIng5 IxQObkhYUEF+33q8yJ1I09Y+R9iMyJXY2rd2HqXUhrAsnDptOcskc5PrTqJr+PqGL/qa tmakfJtjUX2zRlEPDQCNQFmGxaruXajxoDNN8PCZdkIAOEj7r9YM+Zc72vYbBEkFtx1o S6Yg== X-Gm-Message-State: AO0yUKW1D2jHHfDeUsvs/o4PUXTzChr4brMLRATZnMIl0vOgv4W7Wk4L C4Lq1cBtb+gvGR0U0vlGtZI= X-Google-Smtp-Source: AK7set88io4RaJ+ART294KADHQ1jZPyoQw5F4pi8wHbnaAmniBA3Wutkwcm+bacj58AeC1s9Y4DhXQ== X-Received: by 2002:a17:90b:38cc:b0:22c:61c:2d5b with SMTP id nn12-20020a17090b38cc00b0022c061c2d5bmr8857231pjb.20.1675390409931; Thu, 02 Feb 2023 18:13:29 -0800 (PST) Received: from moohyul.svl.corp.google.com ([2620:15c:2d4:203:6755:96ed:3f18:dac4]) by smtp.gmail.com with ESMTPSA id fs23-20020a17090af29700b0022c942b8683sm497249pjb.56.2023.02.02.18.13.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Feb 2023 18:13:29 -0800 (PST) Sender: Namhyung Kim From: Namhyung Kim To: acme@kernel.org, jolsa@kernel.org Cc: peterz@infradead.org, mingo@redhat.com, irogers@google.com, linux-kernel@vger.kernel.org, adrian.hunter@intel.com, linux-perf-users@vger.kernel.org, song@kernel.org, haoluo@google.com, bpf@vger.kernel.org, juri.lelli@redhat.com Subject: [PATCH v2 1/3] perf lock contention: Factor out lock_contention_get_name() Date: Thu, 2 Feb 2023 18:13:22 -0800 Message-Id: <20230203021324.143540-2-namhyung@kernel.org> X-Mailer: git-send-email 2.39.1.519.gcb327c4b5f-goog In-Reply-To: <20230203021324.143540-1-namhyung@kernel.org> References: <20230203021324.143540-1-namhyung@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The lock_contention_get_name() returns a name for the lock stat entry based on the current aggregation mode. As it's called sequentially in a single thread, it can return the address of a static buffer for symbol and offset of the caller. Signed-off-by: Namhyung Kim --- tools/perf/util/bpf_lock_contention.c | 115 +++++++++++++++----------- 1 file changed, 65 insertions(+), 50 deletions(-) diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c index 4902ac331f41..286e52ba9f91 100644 --- a/tools/perf/util/bpf_lock_contention.c +++ b/tools/perf/util/bpf_lock_contention.c @@ -163,9 +163,70 @@ int lock_contention_stop(void) return 0; } +static const char *lock_contention_get_name(struct lock_contention *con, + struct contention_key *key, + u64 *stack_trace) +{ + int idx = 0; + u64 addr; + const char *name = ""; + static char name_buf[KSYM_NAME_LEN]; + struct symbol *sym; + struct map *kmap; + struct machine *machine = con->machine; + + if (con->aggr_mode == LOCK_AGGR_TASK) { + struct contention_task_data task; + int pid = key->aggr_key; + int task_fd = bpf_map__fd(skel->maps.task_data); + + /* do not update idle comm which contains CPU number */ + if (pid) { + struct thread *t = __machine__findnew_thread(machine, /*pid=*/-1, pid); + + if (t == NULL) + return name; + if (!bpf_map_lookup_elem(task_fd, &pid, &task) && + thread__set_comm(t, task.comm, /*timestamp=*/0)) + name = task.comm; + } + return name; + } + + if (con->aggr_mode == LOCK_AGGR_ADDR) { + sym = machine__find_kernel_symbol(machine, key->aggr_key, &kmap); + if (sym) + name = sym->name; + return name; + } + + /* LOCK_AGGR_CALLER: skip lock internal functions */ + while (machine__is_lock_function(machine, stack_trace[idx]) && + idx < con->max_stack - 1) + idx++; + + addr = stack_trace[idx]; + sym = machine__find_kernel_symbol(machine, addr, &kmap); + + if (sym) { + unsigned long offset; + + offset = kmap->map_ip(kmap, addr) - sym->start; + + if (offset == 0) + return sym->name; + + snprintf(name_buf, sizeof(name_buf), "%s+%#lx", sym->name, offset); + } else { + snprintf(name_buf, sizeof(name_buf), "%#lx", (unsigned long)addr); + } + + return name_buf; +} + int lock_contention_read(struct lock_contention *con) { - int fd, stack, task_fd, err = 0; + int fd, stack, err = 0; struct contention_key *prev_key, key; struct contention_data data = {}; struct lock_stat *st = NULL; @@ -175,7 +236,6 @@ int lock_contention_read(struct lock_contention *con) fd = bpf_map__fd(skel->maps.lock_stat); stack = bpf_map__fd(skel->maps.stacks); - task_fd = bpf_map__fd(skel->maps.task_data); con->lost = skel->bss->lost; @@ -195,9 +255,6 @@ int lock_contention_read(struct lock_contention *con) prev_key = NULL; while (!bpf_map_get_next_key(fd, prev_key, &key)) { - struct map *kmap; - struct symbol *sym; - int idx = 0; s32 stack_id; /* to handle errors in the loop body */ @@ -219,61 +276,19 @@ int lock_contention_read(struct lock_contention *con) st->flags = data.flags; st->addr = key.aggr_key; - if (con->aggr_mode == LOCK_AGGR_TASK) { - struct contention_task_data task; - struct thread *t; - int pid = key.aggr_key; - - /* do not update idle comm which contains CPU number */ - if (st->addr) { - bpf_map_lookup_elem(task_fd, &pid, &task); - t = __machine__findnew_thread(machine, /*pid=*/-1, pid); - thread__set_comm(t, task.comm, /*timestamp=*/0); - } - goto next; - } - - if (con->aggr_mode == LOCK_AGGR_ADDR) { - sym = machine__find_kernel_symbol(machine, st->addr, &kmap); - if (sym) - st->name = strdup(sym->name); - goto next; - } - stack_id = key.aggr_key; bpf_map_lookup_elem(stack, &stack_id, stack_trace); - /* skip lock internal functions */ - while (machine__is_lock_function(machine, stack_trace[idx]) && - idx < con->max_stack - 1) - idx++; - - st->addr = stack_trace[idx]; - sym = machine__find_kernel_symbol(machine, st->addr, &kmap); - - if (sym) { - unsigned long offset; - int ret = 0; - - offset = kmap->map_ip(kmap, st->addr) - sym->start; - - if (offset) - ret = asprintf(&st->name, "%s+%#lx", sym->name, offset); - else - st->name = strdup(sym->name); - - if (ret < 0 || st->name == NULL) - break; - } else if (asprintf(&st->name, "%#lx", (unsigned long)st->addr) < 0) { + st->name = strdup(lock_contention_get_name(con, &key, stack_trace)); + if (st->name == NULL) break; - } if (con->save_callstack) { st->callstack = memdup(stack_trace, stack_size); if (st->callstack == NULL) break; } -next: + hlist_add_head(&st->hash_entry, con->result); prev_key = &key;