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[2620:137:e000::1:20]) by mx.google.com with ESMTP id q18-20020a170902f79200b0017275762141si16333655pln.355.2022.08.31.22.04.09; Wed, 31 Aug 2022 22:04:22 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@suse.de header.s=susede2_rsa header.b=S7u1rvnd; dkim=neutral (no key) header.i=@suse.de header.s=susede2_ed25519; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=suse.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232884AbiIAEny (ORCPT + 99 others); Thu, 1 Sep 2022 00:43:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232827AbiIAEn3 (ORCPT ); Thu, 1 Sep 2022 00:43:29 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 370A9ED01C for ; Wed, 31 Aug 2022 21:43:02 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id D2024221EE; Thu, 1 Sep 2022 04:42:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1662007377; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=e8DWylbFwSCb/px9RHGyLSh+EhBiVeZp3bgNDtmW9IA=; b=S7u1rvndnGXFGe9gpIQARWw/22R+6XqNKcNzRqacOvUWansQ9BHdjWh8iRcKXrqgqLuOV2 v6DNKPXLbjMM5RWzIlyGrePp8e4xf2+G40n99CDJxSnS5QOyKG04Sjxj+U0/vhXgjzyXUW RP6Cdu7Ae7QcP7PhwIku/EEFbAb/KXE= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1662007377; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=e8DWylbFwSCb/px9RHGyLSh+EhBiVeZp3bgNDtmW9IA=; b=BPF/tSxXMQDSvEmbgyPhuBR9rysuTMAjY41Rxsu8/nW5dEMdII4hStCGu0uptmYWj17dRU oJeH7qfBX4uymWBw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 32E2C139C4; Thu, 1 Sep 2022 04:42:57 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id WKusCVE4EGPheAAAMHmgww (envelope-from ); Thu, 01 Sep 2022 04:42:57 +0000 From: Oscar Salvador To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Vlastimil Babka , Eric Dumazet , Waiman Long , Suren Baghdasaryan , Oscar Salvador Subject: [PATCH 3/3] mm,page_owner: Filter out stacks by a threshold counter Date: Thu, 1 Sep 2022 06:42:49 +0200 Message-Id: <20220901044249.4624-4-osalvador@suse.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220901044249.4624-1-osalvador@suse.de> References: <20220901044249.4624-1-osalvador@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We want to be able to filter out the output on a threshold basis, in this way we can get rid of a lot of noise and focus only on those stacks which have an allegedly high counter. We can control the threshold value by a new file called 'page_owner_threshold', which is 0 by default. Signed-off-by: Oscar Salvador --- include/linux/stackdepot.h | 3 +- lib/stackdepot.c | 6 ++-- mm/page_owner.c | 61 +++++++++++++++++++++++++++++++++++++- 3 files changed, 66 insertions(+), 4 deletions(-) diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index 20f62039f23a..ee66be40a152 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -26,7 +26,8 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries, stack_action_t action); void stack_depot_dec_count(depot_stack_handle_t handle); int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos, - unsigned long *last_stack); + unsigned long *last_stack, + unsigned long threshold); /* * Every user of stack depot has to call stack_depot_init() during its own init diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 3090ae0f3958..b4a04f09a7b7 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -528,7 +528,8 @@ depot_stack_handle_t stack_depot_save_action(unsigned long *entries, EXPORT_SYMBOL_GPL(stack_depot_save_action); int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos, - unsigned long *last_stack) + unsigned long *last_stack, + unsigned long threshold) { struct stack_record *stack = NULL, *last; struct stack_record **stacks; @@ -547,7 +548,8 @@ int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos, for (; stack; stack = stack->next) { if (!stack->size || stack->size < 0 || stack->size > size || stack->handle.valid != 1 || - refcount_read(&stack->count) < 1) + refcount_read(&stack->count) < 1 || + refcount_read(&stack->count) < threshold) continue; ret += stack_trace_snprint(buf, size, stack->entries, stack->size, 0); diff --git a/mm/page_owner.c b/mm/page_owner.c index 8c67c7eb2451..ef10cf44aaec 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -44,6 +44,7 @@ static depot_stack_handle_t early_handle; static void init_early_allocated_pages(void); static unsigned long last_stack = 0; +static unsigned long threshold_count = 0; static int __init early_page_owner_param(char *buf) { @@ -676,7 +677,8 @@ static ssize_t read_page_owner_stacks(struct file *file, char __user *buf, if (!kbuf) return ENOMEM; - ret += stack_depot_print_stacks_threshold(kbuf, count, pos, &last_stack); + ret += stack_depot_print_stacks_threshold(kbuf, count, pos, &last_stack, + threshold_count); if (copy_to_user(buf, kbuf, ret)) ret = -EFAULT; @@ -687,6 +689,61 @@ static ssize_t read_page_owner_stacks(struct file *file, char __user *buf, return ret; } +static ssize_t read_page_owner_threshold(struct file *file, char __user *buf, + size_t count, loff_t *pos) +{ + char *kbuf; + int ret = 0; + + count = min_t(size_t, count, PAGE_SIZE); + + if (*pos >= count) + return 0; + + kbuf = kmalloc(count, GFP_KERNEL); + if (!kbuf) + return ENOMEM; + + ret = scnprintf(kbuf, count, "%lu\n", threshold_count); + if (copy_to_user(buf, kbuf, ret)) + ret = -EFAULT; + + *pos += count; + kfree(kbuf); + + return ret; +} + +static ssize_t write_page_owner_threshold(struct file *file, const char __user *buf, + size_t count, loff_t *pos) +{ + char *kbuf; + int ret = 0; + + count = min_t(size_t, count, PAGE_SIZE); + kbuf = kmalloc(count, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + if (copy_from_user(kbuf, buf, count)) { + ret = -EFAULT; + goto out; + } + + kbuf[count - 1] = '\0'; + + ret = kstrtoul(kbuf, 10, &threshold_count); + +out: + kfree(kbuf); + return ret ? ret : count; +} + +static const struct file_operations proc_page_owner_threshold = { + .read = read_page_owner_threshold, + .write = write_page_owner_threshold, +}; + static const struct file_operations proc_page_owner_stacks = { .read = read_page_owner_stacks, }; @@ -706,6 +763,8 @@ static int __init pageowner_init(void) &proc_page_owner_operations); debugfs_create_file("page_owner_stacks", 0400, NULL, NULL, &proc_page_owner_stacks); + debugfs_create_file("page_owner_threshold", 0600, NULL, NULL, + &proc_page_owner_threshold); return 0; } -- 2.35.3