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 81D64C77B73 for ; Tue, 30 May 2023 07:36:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 05E2B900002; Tue, 30 May 2023 03:36:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 00E0C6B0074; Tue, 30 May 2023 03:36:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E3EEF900002; Tue, 30 May 2023 03:36:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id D42AC6B0072 for ; Tue, 30 May 2023 03:36:05 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id A32C3120155 for ; Tue, 30 May 2023 07:36:05 +0000 (UTC) X-FDA: 80846112690.19.9201BBD Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf06.hostedemail.com (Postfix) with ESMTP id B768018001F for ; Tue, 30 May 2023 07:36:03 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=CIfs5I+V; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf06.hostedemail.com: domain of pmladek@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=pmladek@suse.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1685432164; 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=fRdPc+Qn5Im2qQM6/X94lLjryR7fpnvxbGC82bbi7Hk=; b=WF6jAMKZrRP174BOrgb78jpJMw6k4S+jPh7GAIXuHdu/FaW0wrFi86Ue+WgV2UWjWUf6Fm Qv2p+C7Vz9Q1bSbNUa0UV3t7xyI67qlMadaPMsuEIWUogO+6kqjSM81UmnGwzDcetU+306 lcVVxI24687Q5e6o34c32sc5C4AyrSg= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=CIfs5I+V; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf06.hostedemail.com: domain of pmladek@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=pmladek@suse.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1685432164; a=rsa-sha256; cv=none; b=Kh2VQmetXa+/BdXzIfAqGdOiuxLeBM/rQWWMa7t0gOyauC6qrCxJqT6XpS4hk9COIaJwy8 78z6WkiQ/LScepDKK8Mr0+zcEK4e6Zd/PLFWjRYGRvuA8d1P5PbAsCHltQ8Ox2+U/NCnfM Z6FCbxtbX1rHpKZB+Xf19dTim9fN7mM= Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 6FC741F889; Tue, 30 May 2023 07:36:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1685432162; 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=fRdPc+Qn5Im2qQM6/X94lLjryR7fpnvxbGC82bbi7Hk=; b=CIfs5I+Vh5kVNfnuR7GkGpPIYkVanFJUxa+kaaIyXeTQ9ZTBi9LQ60264vu+EIUkai9fyG 3XM/Y5L96CFMbELphQu1Waxhu/sEU+hHSQgAbiiYzQj98Fg0IeowLMoQQFWI9OM1DwgJuf OAzj06YL1Hg/E8WfySWF/XtStZzGaug= Received: from suse.cz (pmladek.udp.ovpn2.prg.suse.de [10.100.201.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 2E3AD2C141; Tue, 30 May 2023 07:36:02 +0000 (UTC) Date: Tue, 30 May 2023 09:35:59 +0200 From: Petr Mladek To: Matthew Wilcox Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>, Andrew Morton , linux-mm@kvack.org Subject: Re: [PATCH] Do not print page type when the page has no type Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: B768018001F X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 1udj5rma7zxmpqk3u6757obcdgzkqxpt X-HE-Tag: 1685432163-579509 X-HE-Meta: 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 N7VIopFR idxmAgVvmtZRwj4jx0Wi8IeuO+Gi/HWhhOPZsizRbP70TT6+Ik7CMeOne2GgOOJvyNDBGQTqo3oSQDGw0G1kalGOHaXIUZqaJcj9o0MFJn8NE15FHlR4/vDB/SOz2LCD0qFXNek1u5ahF+iblQzowLh3gvtJLnqyNnjHLVTOuJYr0MX0Odn69x39grk7SCu1QEZAlzJIAqAmOL4SzMUr4Y5aBdpmJBusqNudRBgky4rlz++H+wGc0wHhlhH1nQeZdkGanvbFZhQO28AkRt4Tvd+CSlA== 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 Mon 2023-05-29 16:42:09, Matthew Wilcox wrote: > On Mon, May 29, 2023 at 05:27:29PM +0200, Petr Mladek wrote: > > On Sun 2023-05-28 17:01:59, Hyeonggon Yoo wrote: > > > The code mostly looks fine and the patch makes sense to me. > > > But I'm not sure if it's a nice behavior to print garbage when it does not > > > have a page type, although I can hardly imagine users of this flag other > > > than __dump_page(). I'd rather keep printk part unchanged and add > > > page_has_type() check in __dump_page(). > > > > I agree with Hyeonggon. The change in __dump_page() makes sense. > > But vsprintf() should stay clever and do not print garbage. > > The caller (and, let's face it, there's only ever going to be one > caller) shouldn't pass garbage in the first place. By other words you say that vsprintf() might produce "garbage" when the given value is invalid. And the check is not worth the complexity. It might make sense. Well, we should keep test of the invalid value in test_printf.c. And it would need to be updated when a new page_type is added because it would produce another garbage. From this POV, I would prefer to keep the check in vsprintf.c. All in all. It is about a compromise. I can't judge how much the extra page_type_has_type() complicates mm code. Best Regards, Petr