From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51498C433DB for ; Fri, 26 Feb 2021 01:23:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 16B0F64F33 for ; Fri, 26 Feb 2021 01:23:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229949AbhBZBXN (ORCPT ); Thu, 25 Feb 2021 20:23:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:53214 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230029AbhBZBWX (ORCPT ); Thu, 25 Feb 2021 20:22:23 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6F34864F22; Fri, 26 Feb 2021 01:21:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614302488; bh=Yy65hR/VCSnFoF8TjjRUEO9jIkj4ZEOJI4tgMgSaOac=; h=Date:From:To:Subject:In-Reply-To:From; b=bCdokIrUwm9h89wVxsPImLWMSZwTkp11EnrpQAUkxDT6KNrivhKrUeZnfkbBO6UY7 59zZvSdENVSNDBm6OU5tHiqAtD1Hf/mWGz/mFzinmdUy2+teibtV0RY6gj3mkwVVU1 Yq93COOIY8yqbLuA6NYpxQ49rnuYf970bk/copSg= Date: Thu, 25 Feb 2021 17:21:27 -0800 From: Andrew Morton To: akpm@linux-foundation.org, glider@google.com, linux-mm@kvack.org, minchan@kernel.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vinmenon@codeaurora.org, vjitta@codeaurora.org, ylal@codeaurora.org Subject: [patch 095/118] lib: stackdepot: add support to disable stack depot Message-ID: <20210226012127.5cQ66Y_jc%akpm@linux-foundation.org> In-Reply-To: <20210225171452.713967e96554bb6a53e44a19@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Vijayanand Jitta Subject: lib: stackdepot: add support to disable stack depot Add a kernel parameter stack_depot_disable to disable stack depot. So that stack hash table doesn't consume any memory when stack depot is disabled. The use case is CONFIG_PAGE_OWNER without page_owner=on. Without this patch, stackdepot will consume the memory for the hashtable. By default, it's 8M which is never trivial. With this option, in CONFIG_PAGE_OWNER configured system, page_owner=off, stack_depot_disable in kernel command line, we could save the wasted memory for the hashtable. [akpm@linux-foundation.org: fix CONFIG_STACKDEPOT=n build] Link: https://lkml.kernel.org/r/1611749198-24316-2-git-send-email-vjitta@codeaurora.org Signed-off-by: Vinayak Menon Signed-off-by: Vijayanand Jitta Cc: Alexander Potapenko Cc: Minchan Kim Cc: Yogesh Lal Signed-off-by: Andrew Morton --- Documentation/admin-guide/kernel-parameters.txt | 6 ++ include/linux/stackdepot.h | 9 +++ init/main.c | 2 lib/stackdepot.c | 32 ++++++++++++-- 4 files changed, 45 insertions(+), 4 deletions(-) --- a/Documentation/admin-guide/kernel-parameters.txt~lib-stackdepot-add-support-to-disable-stack-depot +++ a/Documentation/admin-guide/kernel-parameters.txt @@ -5182,6 +5182,12 @@ growing up) the main stack are reserved for no other mapping. Default value is 256 pages. + stack_depot_disable= [KNL] + Setting this to true through kernel command line will + disable the stack depot thereby saving the static memory + consumed by the stack hash table. By default this is set + to false. + stacktrace [FTRACE] Enabled the stack tracer on boot up. --- a/include/linux/stackdepot.h~lib-stackdepot-add-support-to-disable-stack-depot +++ a/include/linux/stackdepot.h @@ -21,4 +21,13 @@ unsigned int stack_depot_fetch(depot_sta unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries); +#ifdef CONFIG_STACKDEPOT +int stack_depot_init(void); +#else +static inline int stack_depot_init(void) +{ + return 0; +} +#endif /* CONFIG_STACKDEPOT */ + #endif --- a/init/main.c~lib-stackdepot-add-support-to-disable-stack-depot +++ a/init/main.c @@ -97,6 +97,7 @@ #include #include #include +#include #include #include @@ -827,6 +828,7 @@ static void __init mm_init(void) init_mem_debugging_and_hardening(); kfence_alloc_pool(); report_meminit(); + stack_depot_init(); mem_init(); /* page_owner must be initialized after buddy is ready */ page_ext_init_flatmem_late(); --- a/lib/stackdepot.c~lib-stackdepot-add-support-to-disable-stack-depot +++ a/lib/stackdepot.c @@ -31,6 +31,7 @@ #include #include #include +#include #define DEPOT_STACK_BITS (sizeof(depot_stack_handle_t) * 8) @@ -145,9 +146,32 @@ static struct stack_record *depot_alloc_ #define STACK_HASH_MASK (STACK_HASH_SIZE - 1) #define STACK_HASH_SEED 0x9747b28c -static struct stack_record *stack_table[STACK_HASH_SIZE] = { - [0 ... STACK_HASH_SIZE - 1] = NULL -}; +static bool stack_depot_disable; +static struct stack_record **stack_table; + +static int __init is_stack_depot_disabled(char *str) +{ + kstrtobool(str, &stack_depot_disable); + if (stack_depot_disable) { + pr_info("Stack Depot is disabled\n"); + stack_table = NULL; + } + return 0; +} +early_param("stack_depot_disable", is_stack_depot_disabled); + +int __init stack_depot_init(void) +{ + if (!stack_depot_disable) { + size_t size = (STACK_HASH_SIZE * sizeof(struct stack_record *)); + int i; + + stack_table = memblock_alloc(size, size); + for (i = 0; i < STACK_HASH_SIZE; i++) + stack_table[i] = NULL; + } + return 0; +} /* Calculate hash for a stack */ static inline u32 hash_stack(unsigned long *entries, unsigned int size) @@ -241,7 +265,7 @@ depot_stack_handle_t stack_depot_save(un unsigned long flags; u32 hash; - if (unlikely(nr_entries == 0)) + if (unlikely(nr_entries == 0) || stack_depot_disable) goto fast_exit; hash = hash_stack(entries, nr_entries); _