From patchwork Thu Mar 3 19:19:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vlastimil Babka X-Patchwork-Id: 12767980 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA8B4C433F5 for ; Thu, 3 Mar 2022 19:19:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5A9DD8D0002; Thu, 3 Mar 2022 14:19:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5597E8D0001; Thu, 3 Mar 2022 14:19:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3FB8D8D0002; Thu, 3 Mar 2022 14:19:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id 2F8228D0001 for ; Thu, 3 Mar 2022 14:19:37 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id E830A2539D for ; Thu, 3 Mar 2022 19:19:36 +0000 (UTC) X-FDA: 79204039152.03.A3CBC41 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf30.hostedemail.com (Postfix) with ESMTP id 0DAD78000A for ; Thu, 3 Mar 2022 19:19:35 +0000 (UTC) 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 63D061F384; Thu, 3 Mar 2022 19:19:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1646335174; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dDgIQIgTJYlvpSaSpluBbjIfP78vvyZKCT97mzfWDlk=; b=uUrqPuVl6riO3SfhAvxwkgWYeEkkc260LjnxDW8b4i4HMGrYnLzSGAGTwschZSYXsrJE4Q dqqqdJKAeSqbWwlOq0X6bPeRPYGpn1aMtUsTMKfUiBHYZnYZibkkkT/M/U+SDuK9XWGXah 2yrG2CYVt7EAmVjN4TWgxTI2bFeBpSE= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1646335174; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dDgIQIgTJYlvpSaSpluBbjIfP78vvyZKCT97mzfWDlk=; b=4euea29H18eU//GUjSXRgv52WDkBaH7sVsXGJhd2xSDfbR142wPC1Vzf+RanKTufqnY6mF MwwjA32gehfyFPAw== 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 2959D13AEE; Thu, 3 Mar 2022 19:19:34 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id vi9gCcYUIWIbewAAMHmgww (envelope-from ); Thu, 03 Mar 2022 19:19:34 +0000 Message-ID: Date: Thu, 3 Mar 2022 20:19:33 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: [PATCH v3r0 1/6] lib/stackdepot: allow requesting early initialization dynamically Content-Language: en-US To: David Rientjes , Christoph Lameter , Joonsoo Kim , Pekka Enberg , Roman Gushchin Cc: Andrew Morton , linux-mm@kvack.org, patches@lists.linux.dev, linux-kernel@vger.kernel.org, Oliver Glitta , Faiyaz Mohammed , Marco Elver , Mike Rapoport , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Imran Khan References: <20220302173122.11939-1-vbabka@suse.cz> <20220302173122.11939-2-vbabka@suse.cz> From: Vlastimil Babka In-Reply-To: <20220302173122.11939-2-vbabka@suse.cz> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 0DAD78000A X-Rspam-User: Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=uUrqPuVl; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=4euea29H; spf=pass (imf30.hostedemail.com: domain of vbabka@suse.cz designates 195.135.220.29 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none X-Stat-Signature: jyiftaakj6f3imrmqhrugeycdn49ebwd X-HE-Tag: 1646335175-449236 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Here's an updated version based on feedback so I don't re-send everything so soon after v2. Also in git: https://git.kernel.org/pub/scm/linux/kernel/git/vbabka/linux.git/log/?h=slub-stackdepot-v3r0 There are only trivial adaptations in patch 3/6 to the stack depot init changes otherwise. Thanks, Vlastimil ----8<---- From 230ebae0f83540574d167f9ba1f71d3f602ca410 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Wed, 2 Mar 2022 12:02:22 +0100 Subject: [PATCH v3 1/6] lib/stackdepot: allow requesting early initialization dynamically In a later patch we want to add stackdepot support for object owner tracking in slub caches, which is enabled by slub_debug boot parameter. This creates a bootstrap problem as some caches are created early in boot when slab_is_available() is false and thus stack_depot_init() tries to use memblock. But, as reported by Hyeonggon Yoo [1] we are already beyond memblock_free_all(). Ideally memblock allocation should fail, yet it succeeds, but later the system crashes, which is a separately handled issue. To resolve this boostrap issue in a robust way, this patch adds another way to request stack_depot_early_init(), which happens at a well-defined point of time. In addition to build-time CONFIG_STACKDEPOT_ALWAYS_INIT, code that's e.g. processing boot parameters (which happens early enough) can call a new function stack_depot_want_early_init(), which sets a flag that stack_depot_early_init() will check. In this patch we also convert page_owner to this approach. While it doesn't have the bootstrap issue as slub, it's also a functionality enabled by a boot param and can thus request stack_depot_early_init() with memblock allocation instead of later initialization with kvmalloc(). As suggested by Mike, make stack_depot_early_init() only attempt memblock allocation and stack_depot_init() only attempt kvmalloc(). Also change the latter to kvcalloc(). In both cases we can lose the explicit array zeroing, which the allocations do already. As suggested by Marco, provide empty implementations of the init functions for !CONFIG_STACKDEPOT builds to simplify the callers. [1] https://lore.kernel.org/all/YhnUcqyeMgCrWZbd@ip-172-31-19-208.ap-northeast-1.compute.internal/ Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Suggested-by: Mike Rapoport Suggested-by: Marco Elver Signed-off-by: Vlastimil Babka Reviewed-by: Marco Elver Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Mike Rapoport --- include/linux/stackdepot.h | 26 ++++++++++++--- lib/stackdepot.c | 67 +++++++++++++++++++++++++------------- mm/page_owner.c | 9 +++-- 3 files changed, 73 insertions(+), 29 deletions(-) diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index 17f992fe6355..bc2797955de9 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -20,18 +20,36 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries, gfp_t gfp_flags, bool can_alloc); /* - * Every user of stack depot has to call this during its own init when it's - * decided that it will be calling stack_depot_save() later. + * Every user of stack depot has to call stack_depot_init() during its own init + * when it's decided that it will be calling stack_depot_save() later. This is + * recommended for e.g. modules initialized later in the boot process, when + * slab_is_available() is true. * * The alternative is to select STACKDEPOT_ALWAYS_INIT to have stack depot * enabled as part of mm_init(), for subsystems where it's known at compile time * that stack depot will be used. + * + * Another alternative is to call stack_depot_want_early_init(), when the + * decision to use stack depot is taken e.g. when evaluating kernel boot + * parameters, which precedes the enablement point in mm_init(). + * + * stack_depot_init() and stack_depot_want_early_init() can be called regardless + * of CONFIG_STACKDEPOT and are no-op when disabled. The actual save/fetch/print + * functions should only be called from code that makes sure CONFIG_STACKDEPOT + * is enabled. */ +#ifdef CONFIG_STACKDEPOT int stack_depot_init(void); -#ifdef CONFIG_STACKDEPOT_ALWAYS_INIT -static inline int stack_depot_early_init(void) { return stack_depot_init(); } +void __init stack_depot_want_early_init(void); + +/* This is supposed to be called only from mm_init() */ +int __init stack_depot_early_init(void); #else +static inline int stack_depot_init(void) { return 0; } + +static inline void stack_depot_want_early_init(void) { } + static inline int stack_depot_early_init(void) { return 0; } #endif diff --git a/lib/stackdepot.c b/lib/stackdepot.c index bf5ba9af0500..0a5916f1e7a3 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -66,6 +66,9 @@ struct stack_record { unsigned long entries[]; /* Variable-sized array of entries. */ }; +static bool __stack_depot_want_early_init __initdata = IS_ENABLED(CONFIG_STACKDEPOT_ALWAYS_INIT); +static bool __stack_depot_early_init_passed __initdata; + static void *stack_slabs[STACK_ALLOC_MAX_SLABS]; static int depot_index; @@ -162,38 +165,58 @@ static int __init is_stack_depot_disabled(char *str) } early_param("stack_depot_disable", is_stack_depot_disabled); -/* - * __ref because of memblock_alloc(), which will not be actually called after - * the __init code is gone, because at that point slab_is_available() is true - */ -__ref int stack_depot_init(void) +void __init stack_depot_want_early_init(void) +{ + /* Too late to request early init now */ + WARN_ON(__stack_depot_early_init_passed); + + __stack_depot_want_early_init = true; +} + +int __init stack_depot_early_init(void) +{ + size_t size; + int i; + + /* This is supposed to be called only once, from mm_init() */ + if (WARN_ON(__stack_depot_early_init_passed)) + return 0; + + __stack_depot_early_init_passed = true; + + if (!__stack_depot_want_early_init || stack_depot_disable) + return 0; + + pr_info("Stack Depot early init allocating hash table with memblock_alloc\n"); + size = (STACK_HASH_SIZE * sizeof(struct stack_record *)); + stack_table = memblock_alloc(size, SMP_CACHE_BYTES); + + if (!stack_table) { + pr_err("Stack Depot hash table allocation failed, disabling\n"); + stack_depot_disable = true; + return -ENOMEM; + } + + return 0; +} + +int stack_depot_init(void) { static DEFINE_MUTEX(stack_depot_init_mutex); + int ret = 0; mutex_lock(&stack_depot_init_mutex); if (!stack_depot_disable && !stack_table) { - size_t size = (STACK_HASH_SIZE * sizeof(struct stack_record *)); - int i; - - if (slab_is_available()) { - pr_info("Stack Depot allocating hash table with kvmalloc\n"); - stack_table = kvmalloc(size, GFP_KERNEL); - } else { - pr_info("Stack Depot allocating hash table with memblock_alloc\n"); - stack_table = memblock_alloc(size, SMP_CACHE_BYTES); - } - if (stack_table) { - for (i = 0; i < STACK_HASH_SIZE; i++) - stack_table[i] = NULL; - } else { + pr_info("Stack Depot allocating hash table with kvcalloc\n"); + stack_table = kvcalloc(STACK_HASH_SIZE, sizeof(struct stack_record *), GFP_KERNEL); + if (!stack_table) { pr_err("Stack Depot hash table allocation failed, disabling\n"); stack_depot_disable = true; - mutex_unlock(&stack_depot_init_mutex); - return -ENOMEM; + ret = -ENOMEM; } } mutex_unlock(&stack_depot_init_mutex); - return 0; + return ret; } EXPORT_SYMBOL_GPL(stack_depot_init); diff --git a/mm/page_owner.c b/mm/page_owner.c index 99e360df9465..4313f8212a83 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -42,7 +42,12 @@ static void init_early_allocated_pages(void); static int __init early_page_owner_param(char *buf) { - return kstrtobool(buf, &page_owner_enabled); + int ret = kstrtobool(buf, &page_owner_enabled); + + if (page_owner_enabled) + stack_depot_want_early_init(); + + return ret; } early_param("page_owner", early_page_owner_param); @@ -80,8 +85,6 @@ static __init void init_page_owner(void) if (!page_owner_enabled) return; - stack_depot_init(); - register_dummy_stack(); register_failure_stack(); register_early_stack();