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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham 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 A776CC433C1 for ; Sat, 27 Mar 2021 21:38:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 22F4061992 for ; Sat, 27 Mar 2021 21:38:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 22F4061992 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gentoo.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 49B8F6B0074; Sat, 27 Mar 2021 17:38:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 44B746B0075; Sat, 27 Mar 2021 17:38:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 313586B0078; Sat, 27 Mar 2021 17:38:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0118.hostedemail.com [216.40.44.118]) by kanga.kvack.org (Postfix) with ESMTP id 172A86B0074 for ; Sat, 27 Mar 2021 17:38:05 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id BFDA9BF12 for ; Sat, 27 Mar 2021 21:38:04 +0000 (UTC) X-FDA: 77966967288.27.6641C11 Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) by imf01.hostedemail.com (Postfix) with ESMTP id 490C85001529 for ; Sat, 27 Mar 2021 21:38:01 +0000 (UTC) Date: Sat, 27 Mar 2021 21:37:48 +0000 From: Sergei Trofimovich To: Andrew Morton , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: add page_owner_stack=off to make stack collection optional Message-ID: <20210327213748.2f7a5692@sf> In-Reply-To: <20210321212501.2504947-1-slyfox@gentoo.org> References: <20210321212501.2504947-1-slyfox@gentoo.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 490C85001529 X-Stat-Signature: 4c4z7ojh9b3uw3dh8aspweycxtafcxcp Received-SPF: none (gentoo.org>: No applicable sender policy available) receiver=imf01; identity=mailfrom; envelope-from=""; helo=smtp.gentoo.org; client-ip=140.211.166.183 X-HE-DKIM-Result: none/none X-HE-Tag: 1616881081-864428 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: On Sun, 21 Mar 2021 21:25:01 +0000 Sergei Trofimovich wrote: > On some architectures (like ia64) stack walking is slow > and currently requires memory allocation. This causes stack > collection for page_owner=on to fall into recursion. > > This patch implements a page_owner_stack=off to allow page stats > collection. More user friendly alternative would be to have a GFP_ flag similar to __GFP_NOLOCKDEP which would allow us to skip the recursion. I'll prepare alternative patch. > Signed-off-by: Sergei Trofimovich > --- > .../admin-guide/kernel-parameters.txt | 6 +++++ > mm/Kconfig.debug | 3 ++- > mm/page_owner.c | 23 +++++++++++++------ > 3 files changed, 24 insertions(+), 8 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 04545725f187..3e710c4ab4df 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -3518,6 +3518,12 @@ > we can turn it on. > on: enable the feature > > + page_owner_stack= [KNL] Boot-time parameter option disabling stack > + collection of page allocation. Has effect only if > + "page_owner=on" is set. Useful for cases when stack > + collection is too slow or not feasible. > + off: disable the feature > + > page_poison= [KNL] Boot-time parameter changing the state of > poisoning on the buddy allocator, available with > CONFIG_PAGE_POISONING=y. > diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug > index 1e73717802f8..c1ecaf066c93 100644 > --- a/mm/Kconfig.debug > +++ b/mm/Kconfig.debug > @@ -57,7 +57,8 @@ config PAGE_OWNER > help to find bare alloc_page(s) leaks. Even if you include this > feature on your build, it is disabled in default. You should pass > "page_owner=on" to boot parameter in order to enable it. Eats > - a fair amount of memory if enabled. See tools/vm/page_owner_sort.c > + a fair amount of memory if enabled. Call chain tracking can be > + disabled with "page_owner_stack=off". See tools/vm/page_owner_sort.c > for user-space helper. > > If unsure, say N. > diff --git a/mm/page_owner.c b/mm/page_owner.c > index d15c7c4994f5..2cc1113fa28d 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -31,6 +31,7 @@ struct page_owner { > }; > > static bool page_owner_enabled = false; > +static bool page_owner_stack_enabled = true; > DEFINE_STATIC_KEY_FALSE(page_owner_inited); > > static depot_stack_handle_t dummy_handle; > @@ -41,21 +42,26 @@ static void init_early_allocated_pages(void); > > static int __init early_page_owner_param(char *buf) > { > - if (!buf) > - return -EINVAL; > - > - if (strcmp(buf, "on") == 0) > - page_owner_enabled = true; > - > - return 0; > + return kstrtobool(buf, &page_owner_enabled); > } > early_param("page_owner", early_page_owner_param); > > +static int __init early_page_owner_stack_param(char *buf) > +{ > + return kstrtobool(buf, &page_owner_stack_enabled); > +} > +early_param("page_owner_stack", early_page_owner_stack_param); > + > static bool need_page_owner(void) > { > return page_owner_enabled; > } > > +static bool need_page_owner_stack(void) > +{ > + return page_owner_stack_enabled; > +} > + > static __always_inline depot_stack_handle_t create_dummy_stack(void) > { > unsigned long entries[4]; > @@ -122,6 +128,9 @@ static noinline depot_stack_handle_t save_stack(gfp_t flags) > depot_stack_handle_t handle; > unsigned int nr_entries; > > + if (!need_page_owner_stack()) > + return failure_handle; > + > nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2); > > /* > -- > 2.31.0 > -- Sergei