From nobody Wed Dec 17 10:05:35 2025 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 CDB00C77B75 for ; Fri, 21 Apr 2023 10:15:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231434AbjDUKPE (ORCPT ); Fri, 21 Apr 2023 06:15:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231342AbjDUKOk (ORCPT ); Fri, 21 Apr 2023 06:14:40 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 706FCC16B for ; Fri, 21 Apr 2023 03:14:39 -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-out2.suse.de (Postfix) with ESMTPS id 236311FDDE; Fri, 21 Apr 2023 10:14:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1682072078; 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=zE4KUQItN/3/UV4PaOZpW67hAUQM7k7JGXQXpSUX7jM=; b=LxPC06RfpZaf/PV59ic/kcvwI8MQ/gLjs6JkYCNJ/RNb4xRaG70GAN+PGm+8H+ryznSgpc YrF8dckTbYzILZ5H8nPsp0rNBoS1mIsN58UGleQbLSkmKQt45pkJxWA4xeNLFKhm3E6CSB bgDU8rZ29b2J1dRT10rROtiAB8ISjTE= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1682072078; 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=zE4KUQItN/3/UV4PaOZpW67hAUQM7k7JGXQXpSUX7jM=; b=TfOtgFn8V7n2eVcwCSKoDkdsIoC3KMz6ZTBfi4H+A0+FegXVYPQtLSIWwe1Nz6zW8lDvXx 1QolS+TvzBBDJnBQ== 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 542F01390E; Fri, 21 Apr 2023 10:14:37 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id GNpvEQ1iQmRNaAAAMHmgww (envelope-from ); Fri, 21 Apr 2023 10:14:37 +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 , Marco Elver , Andrey Konovalov , Alexander Potapenko , Oscar Salvador Subject: [PATCH v4 2/3] mm, page_owner: Add page_owner_stacks file to print out only stacks and their counte Date: Fri, 21 Apr 2023 12:14:14 +0200 Message-Id: <20230421101415.5734-3-osalvador@suse.de> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230421101415.5734-1-osalvador@suse.de> References: <20230421101415.5734-1-osalvador@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" We might be only interested in knowing about stacks <-> count relationship, so instead of having to fiddle with page_owner output and screen through pfns, let us add a new file called 'page_owner_stacks' that does just that. By cating such file, we will get all the stacktraces followed by its counter, so we can have a more global view. Signed-off-by: Oscar Salvador #include #include +#include +#include =20 #define DEPOT_HANDLE_BITS (sizeof(depot_stack_handle_t) * 8) =20 @@ -499,6 +501,77 @@ static struct stack_record *stack_depot_getstack(depot= _stack_handle_t handle) return stack; } =20 +#ifdef CONFIG_PAGE_OWNER +void *stack_start(struct seq_file *m, loff_t *ppos) +{ + unsigned long *table =3D m->private; + struct stack_record **stacks, *stack; + + /* First time */ + if (*ppos =3D=3D 0) + *table =3D 0; + + if (*ppos =3D=3D -1UL) + return NULL; + + stacks =3D &stack_table[*table]; + stack =3D (struct stack_record *)stacks; + + return stack; +} + +void *stack_next(struct seq_file *m, void *v, loff_t *ppos) +{ + unsigned long *table =3D m->private; + unsigned long nr_table =3D *table; + struct stack_record *next =3D NULL, *stack =3D v, **stacks; + unsigned long stack_table_entries =3D stack_hash_mask + 1; + + if (!stack) { +new_table: + /* New table */ + nr_table++; + if (nr_table >=3D stack_table_entries) + goto out; + stacks =3D &stack_table[nr_table]; + stack =3D (struct stack_record *)stacks; + next =3D stack; + } else { + next =3D stack->next; + } + + if (!next) + goto new_table; + +out: + *table =3D nr_table; + *ppos =3D (nr_table >=3D stack_table_entries) ? -1UL : *ppos + 1; + return next; +} + +int stack_print(struct seq_file *m, void *v) +{ + char *buf; + int ret =3D 0; + struct stack_record *stack =3Dv; + + if (!stack->size || stack->size < 0 || + stack->size > PAGE_SIZE || stack->handle.valid !=3D 1 || + refcount_read(&stack->count) < 1) + return 0; + + buf =3D kzalloc(PAGE_SIZE, GFP_KERNEL); + ret +=3D stack_trace_snprint(buf, PAGE_SIZE, stack->entries, stack->size,= 0); + scnprintf(buf + ret, PAGE_SIZE - ret, "stack count: %d\n\n", + refcount_read(&stack->count)); + seq_printf(m, buf); + seq_puts(m, "\n\n"); + kfree(buf); + + return 0; +} +#endif + unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries) { diff --git a/mm/page_owner.c b/mm/page_owner.c index b6637524e442..b191ad1d41f9 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -718,6 +718,31 @@ static const struct file_operations proc_page_owner_op= erations =3D { .llseek =3D lseek_page_owner, }; =20 +static void stack_stop(struct seq_file *m, void *v) +{ + return; +} + +static const struct seq_operations page_owner_stack_op =3D { + .start =3D stack_start, + .next =3D stack_next, + .stop =3D stack_stop, + .show =3D stack_print +}; + +static int page_owner_stack_open(struct inode *inode, struct file *file) +{ + return seq_open_private(file, &page_owner_stack_op, + sizeof(unsigned long)); +} + +const struct file_operations page_owner_stack_operations =3D { + .open =3D page_owner_stack_open, + .read =3D seq_read, + .llseek =3D seq_lseek, + .release =3D seq_release, +}; + static int __init pageowner_init(void) { if (!static_branch_unlikely(&page_owner_inited)) { @@ -728,6 +753,9 @@ static int __init pageowner_init(void) debugfs_create_file("page_owner", 0400, NULL, NULL, &proc_page_owner_operations); =20 + debugfs_create_file("page_owner_stacks", S_IRUSR, NULL, NULL, + &page_owner_stack_operations); + return 0; } late_initcall(pageowner_init) --=20 2.35.3