From patchwork Thu Feb 2 05:04:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namhyung Kim X-Patchwork-Id: 13125306 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 BE9F2C636D7 for ; Thu, 2 Feb 2023 05:05:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229651AbjBBFFD (ORCPT ); Thu, 2 Feb 2023 00:05:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231160AbjBBFFC (ORCPT ); Thu, 2 Feb 2023 00:05:02 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE22413D6F; Wed, 1 Feb 2023 21:05:00 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id mi9so828312pjb.4; Wed, 01 Feb 2023 21:05:00 -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=fOU/DIS3FJule2LiTwVBX9EbwBghUDusHfGnb+FT/ZA=; b=lCF2pcP/QHMEJGiIPMBZVeaiXjF3+zNSoFftzLQdl+mbYFwFkeNee9PfGMQ6ouvTJw G4Mnlg9vSoQ6ljihWWKl2x0ghROZz+9fqYZkBKkpz8UFnspiVr2fFygI5XQwUM0zrwgV 0GKb+b4Y4Y4vJ32xqROGYeiDUwpI5ygQcWBb0lpYgIZv5nM7yNqA1/1YSG03NSPdGLgs CWlcKajH8NQi74hLdtJhl2zZYhPjCse2ZRChebemZRFvfRxSQoUKxIVFJfTdBbh3E+7A Qq7i9hx1j7e5lfNA9A9vtrGcVTVtQkem/7L8IFWaYSC9jgnh1A3/7ZHPuNAXzrWmofxM +JUQ== 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=fOU/DIS3FJule2LiTwVBX9EbwBghUDusHfGnb+FT/ZA=; b=YCGBORA5tUwe1uMl7DC1Ijq+vW7nB1MBbPNf3q9BQHZ6F7PQ8SWYjEmGfYTheuVyxh SxFcQ6Wre6j4yADJMcVTEH8FfqF7Djdm9iEEl61AjScmlTg98ublJUgbKMj70nWiab28 IeN0aApzC814Rh+YURhxwPriBZFSh48NdJHDFRtH2HXMQ7rvyQ2lmPJqDmHOT95eDbFg T7KFuCWm4AUuJlXv6OuGKV+E6YVYqq0MNe011jC3c4wkeazKxciBX3BHiyxgj+zLHokQ 7dj7Sf5Z/MZ1HAO9l/0DLEJCVoyktwG2RorWd1AnT++5F9KxImXZOCX+lOKCHaUffMxI sSDA== X-Gm-Message-State: AO0yUKWYke8qE2vfWbYpe0jQJ8JFTkNxkpIWkQES5m89n/SYZd4kgjIk 2dD0eKyYvnOmkwXLGUFxt1k= X-Google-Smtp-Source: AK7set+rqv8FEdCNstXyCgW9LESMkUr3P2/DjhcrPxP/JkZfTormucnKpiCc4y+WzTzaLnBJnGnY/A== X-Received: by 2002:a17:90a:db8e:b0:22c:147d:137f with SMTP id h14-20020a17090adb8e00b0022c147d137fmr5356825pjv.17.1675314300163; Wed, 01 Feb 2023 21:05:00 -0800 (PST) Received: from balhae.hsd1.ca.comcast.net ([2601:647:6780:ff0:8899:7288:e54d:8b87]) by smtp.gmail.com with ESMTPSA id t3-20020a17090aba8300b0022bb3ee9b68sm2238374pjr.13.2023.02.01.21.04.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Feb 2023 21:04:59 -0800 (PST) Sender: Namhyung Kim From: Namhyung Kim To: Arnaldo Carvalho de Melo , Jiri Olsa Cc: Ingo Molnar , Peter Zijlstra , LKML , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Song Liu , Hao Luo , bpf@vger.kernel.org Subject: [PATCH 1/4] perf lock contention: Factor out lock_contention_get_name() Date: Wed, 1 Feb 2023 21:04:52 -0800 Message-Id: <20230202050455.2187592-2-namhyung@kernel.org> X-Mailer: git-send-email 2.39.1.456.gfc5497dd1b-goog In-Reply-To: <20230202050455.2187592-1-namhyung@kernel.org> References: <20230202050455.2187592-1-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 | 113 ++++++++++++++------------ 1 file changed, 63 insertions(+), 50 deletions(-) diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c index 4902ac331f41..967ce168f163 100644 --- a/tools/perf/util/bpf_lock_contention.c +++ b/tools/perf/util/bpf_lock_contention.c @@ -163,9 +163,68 @@ 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; + struct thread *t; + 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) { + bpf_map_lookup_elem(task_fd, &pid, &task); + t = __machine__findnew_thread(machine, /*pid=*/-1, pid); + 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 +234,6 @@ 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 +253,6 @@ 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 +274,19 @@ 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;