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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 069A7C48297 for ; Fri, 9 Feb 2024 21:38:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 76D006B0080; Fri, 9 Feb 2024 16:38:02 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 71CBA6B0081; Fri, 9 Feb 2024 16:38:02 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5BD806B0082; Fri, 9 Feb 2024 16:38:02 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 482756B0080 for ; Fri, 9 Feb 2024 16:38:02 -0500 (EST) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 1A9BFA0924 for ; Fri, 9 Feb 2024 21:38:02 +0000 (UTC) X-FDA: 81773578404.16.A458018 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf20.hostedemail.com (Postfix) with ESMTP id C3F671C001D for ; Fri, 9 Feb 2024 21:37:59 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="BHiJ/fyF"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b="0WV/mw3F"; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="BHiJ/fyF"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b="0WV/mw3F"; spf=pass (imf20.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.130 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1707514680; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=skJOimG74wL0Kt4yAu7/GY9/doYdDYoQCHINdOb8LWE=; b=oDKhre4dL5/ZdqtfhuXey+TAdgbbx8pIZrz9c2EOZw6+5MN0B73wc48rgc0fydwr2TjHBp fk7Vsxc9evmfUeckJ0JfxAQ9Y6Z5TeH+Zy/WMffXVGQmL2VLLrwwvoGWz15LpB2DTvsi4M BUijTCvRi0pvMjeYBxWCRIjeroFRVKY= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="BHiJ/fyF"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b="0WV/mw3F"; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="BHiJ/fyF"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b="0WV/mw3F"; spf=pass (imf20.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.130 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1707514680; a=rsa-sha256; cv=none; b=UQ3bIGJJxc3TZeNVuPLEREqqJPsBofYWxzAeNskRgGn27gz+JuwxPA9FfrfxZqcz1SNWdg IUYt1fLES/YZ+r5zYrSRQ1jR4dMYD3cy7Fhp08JXIiEUNW8ukgVtvktnbKwkEAfnH0bPkw jY9DljtWC8EQXmr5LzWPlVx8YJZLs8k= Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 2A46F21CDF; Fri, 9 Feb 2024 21:37:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1707514678; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=skJOimG74wL0Kt4yAu7/GY9/doYdDYoQCHINdOb8LWE=; b=BHiJ/fyFlRf3shpL0JD0JPWEHo5RPM8nPQ/2Xbinq4YYaFPCXEK4Zj0BuTQUYRGrHeZ49s UBTwS2oOaYCKBxXMo1Z7k+8Edv8D2EczFtkZqR7l/6SesTs9ytQHmQyMF7iX/sJ4UTU0YY 1iepgLiPGsA1zjTe1e9keK+Xcz4jaV0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1707514678; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=skJOimG74wL0Kt4yAu7/GY9/doYdDYoQCHINdOb8LWE=; b=0WV/mw3FDwlT4P7xVuo9jiWH0bXF7nkIkcjMeY2iEqaNcwipP5jLhFmo4Jbs38ee+MwLfo bk75/3H/nP+GkADQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1707514678; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=skJOimG74wL0Kt4yAu7/GY9/doYdDYoQCHINdOb8LWE=; b=BHiJ/fyFlRf3shpL0JD0JPWEHo5RPM8nPQ/2Xbinq4YYaFPCXEK4Zj0BuTQUYRGrHeZ49s UBTwS2oOaYCKBxXMo1Z7k+8Edv8D2EczFtkZqR7l/6SesTs9ytQHmQyMF7iX/sJ4UTU0YY 1iepgLiPGsA1zjTe1e9keK+Xcz4jaV0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1707514678; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=skJOimG74wL0Kt4yAu7/GY9/doYdDYoQCHINdOb8LWE=; b=0WV/mw3FDwlT4P7xVuo9jiWH0bXF7nkIkcjMeY2iEqaNcwipP5jLhFmo4Jbs38ee+MwLfo bk75/3H/nP+GkADQ== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 9E5AA139E7; Fri, 9 Feb 2024 21:37:57 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id myfxIzWbxmWqaQAAD6G6ig (envelope-from ); Fri, 09 Feb 2024 21:37:57 +0000 Date: Fri, 9 Feb 2024 22:39:04 +0100 From: Oscar Salvador To: Marco Elver Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Vlastimil Babka , Andrey Konovalov , Alexander Potapenko Subject: Re: [PATCH v7 2/4] mm,page_owner: Implement the tracking of the stacks count Message-ID: References: <20240208234539.19113-1-osalvador@suse.de> <20240208234539.19113-3-osalvador@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: C3F671C001D X-Rspam-User: X-Stat-Signature: 1jn7tgn5bzhdhqfahqfstt4idfjqumo8 X-Rspamd-Server: rspam01 X-HE-Tag: 1707514679-711527 X-HE-Meta: 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 MX5mvJCf 8DqRQimeI69rLRQWpecYX3nrVFudltqElw8O3YMkvxI0kSeZSkfJw1s0NuwnPKSGbXWXXMYPCm8EmVT6tRSaWtN+KwwztQ4QiYQF7EzE15SX6GtnXNHlxRecNvRVZHoozFYT8VSfJg6D+QUyHVXYyAS9EdcdcWhr0q6Ka+iTNQNCXPWjDH2KaaTaQa3/szlzfUxHsvbam5EIAz4u3iHCDRmGW0OFcTJ8ReC/0qSO0ioF+KNtmqSI5gl0LCa0zcYo1uTDj 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: List-Subscribe: List-Unsubscribe: On Fri, Feb 09, 2024 at 08:45:00AM +0100, Marco Elver wrote: > > +/** > > + * stack_depo_get_stack - Get a pointer to a stack struct > > Typo: "depo" -> depot > > I would also write "stack_record struct", because "stack struct" does not exist. Fixed. > > + * @handle: Stack depot handle > > + * > > + * Return: Returns a pointer to a stack struct > > + */ > > +struct stack_record *stack_depot_get_stack(depot_stack_handle_t handle); > > I don't know what other usecases there are for this, but I'd want to > make make sure we give users a big hint to avoid unnecessary uses of > this function. > > Perhaps we also want to mark it as somewhat internal, e.g. by > prefixing it with __. So I'd call it __stack_depot_get_stack_record(). Yes, I went with __stack_depot_get_stack_record(), and I updated its doc in stackdepot.h, mentioning that is only for internal purposes. > > +static void inc_stack_record_count(depot_stack_handle_t handle) > > +{ > > + struct stack_record *stack = stack_depot_get_stack(handle); > > + > > + if (stack) > > + refcount_inc(&stack->count); > > +} > > In the latest stackdepot version in -next, the count is initialized to > REFCOUNT_SATURATED to warn if a non-refcounted entry is suddenly used > as a refcounted one. In your case this is intentional and there is no > risk that the entry will be evicted, so that's ok. But you need to set > the refcount to 1 somewhere here on the initial stack_depot_save(). Well, I went with something like: static void inc_stack_record_count(depot_stack_handle_t handle) { struct stack_record *stack = __stack_depot_get_stack_record(handle); if (stack) { /* * New stack_records that do not use STACK_DEPOT_FLAG_GET start * with REFCOUNT_SATURATED to catch spurious increments of their * refcount. * Since we do not use STACK_DEPOT_FLAG_{GET,PUT} API, let us * set a refcount of 1 ourselves. */ if (refcount_read(&stack->count) == REFCOUNT_SATURATED) refcount_set(&stack->count, 1); refcount_inc(&stack->count); } } -- Oscar Salvador SUSE Labs