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 33A03C4332F for ; Thu, 29 Dec 2022 13:31:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B7DE68E0002; Thu, 29 Dec 2022 08:31:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B2E838E0001; Thu, 29 Dec 2022 08:31:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9D00D8E0002; Thu, 29 Dec 2022 08:31:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 8A07E8E0001 for ; Thu, 29 Dec 2022 08:31:08 -0500 (EST) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 57BD6C0A14 for ; Thu, 29 Dec 2022 13:31:08 +0000 (UTC) X-FDA: 80295429816.26.8C95FA3 Received: from mail-pf1-f179.google.com (mail-pf1-f179.google.com [209.85.210.179]) by imf03.hostedemail.com (Postfix) with ESMTP id A159320018 for ; Thu, 29 Dec 2022 13:31:06 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=CHkKg4pK; spf=pass (imf03.hostedemail.com: domain of 42.hyeyoo@gmail.com designates 209.85.210.179 as permitted sender) smtp.mailfrom=42.hyeyoo@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1672320666; a=rsa-sha256; cv=none; b=Clt2SSJLqs2GwG/6gaie5lqcgpuPKDrbraHVjJ5jwEokd1/3aoRl44liH5Or8l0eEBjvDl fBBA+1EwfERWgdEf+QSt+ACTHTmzoeoc36UPrgV3ymXnja50iP99zGIfiES8nvBTK+BA9G AqqEgjKe0BcMHdzb+eMcIXJVqhvhoDA= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=CHkKg4pK; spf=pass (imf03.hostedemail.com: domain of 42.hyeyoo@gmail.com designates 209.85.210.179 as permitted sender) smtp.mailfrom=42.hyeyoo@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1672320666; 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=nJyXOHIJy199WKQmrcss/MftC0S714TuH1DdiOZFBe8=; b=FMOchLrMeL+s+8okLGJYjuUAnfOLJ3fpSliqPH+BAaTm3BbcrdeGAJ6OA4JSEPWkImzsM1 AbG6E8CpokN8o0xt/w2BE5t4ho2MO97ADt1hrcZsC+ignqnM3GCfwiK9zLfG2B65Bb0ht2 MdmmHDjyP6L3slw8rk0ITuHRMS1LidM= Received: by mail-pf1-f179.google.com with SMTP id g20so4398199pfb.3 for ; Thu, 29 Dec 2022 05:31:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=nJyXOHIJy199WKQmrcss/MftC0S714TuH1DdiOZFBe8=; b=CHkKg4pKUiD5Odl/DCpWFAuhudcLG+uwXgtoD/ao8t24YBoeFQPtIFtL9iYoyjJmf2 rVO+pZK2HGEfrsDMGUp0bvwU2p1booGk3yA9BFxWkEWaccAcgolHwYxR3P3KjxpXi6IT uN11cTNyqmdLPzm+fuXJluv/X/McnSBpD8S230Gs83bUxt761lP7AmIM6XgPGDiScq0V Qs9MShVIMhVCdo6U8RuouVFr62htSbaIbXJfOfxS+1BLA+bUQDsJgVMp5FS2KJIhGDXZ 4zTmWEbHUJHSnGA3dZJknElLIqkHLw2fIDpFS2ZdrLtysAU3Te8AjFwOZLAXJGJRnUIm QsDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=nJyXOHIJy199WKQmrcss/MftC0S714TuH1DdiOZFBe8=; b=ZtSypeBSOaGDHHv4x7KByNMw1+FyiIpzmsPLg8qRtW1eOrXWjaCecNBoXFoD+lDrhV vqptqVkwBp05NRWO6VI60UkuK/k4390hpYcVeK1pOZgAcRhbPiTOLE/F2LLrH3zKAonF HvZvWYjOsXAwD52KpTZJYGW2+L0XgjnLRwf1fHRjDMHrUd9ZmASrl4GoNeF3vqZl/oQH jJy08eSJzA8Py93pwHCCxyYWEXZIDwGWKLOG3f4pm7L70gExCN2LeA9HMZqnhYuyrW7j x5TLfq2XcYmNhX7nkeR5QG4ATiH04HFyMwQAfJwnOPHia6I7mEGEzsPfCWJiWsRQyIAi 6AIQ== X-Gm-Message-State: AFqh2kp/lOGA0LeU3z56cCs+cyU/W6KzFDZxuSFFvHZkuwUMQ7Zf6qdL pCp9Y5bOCUD6E8x45G5yeK8= X-Google-Smtp-Source: AMrXdXtJuDlA/aYufo+aCodeU7FfCubBFPa1GVtVH7kHMYxHgSbLUUfM78MOv1CAUv7d4IwfQwkw6w== X-Received: by 2002:a62:b412:0:b0:581:3557:f75b with SMTP id h18-20020a62b412000000b005813557f75bmr12396832pfn.5.1672320665523; Thu, 29 Dec 2022 05:31:05 -0800 (PST) Received: from hyeyoo ([114.29.91.56]) by smtp.gmail.com with ESMTPSA id 12-20020a62170c000000b005769436a23dsm12089673pfx.218.2022.12.29.05.31.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Dec 2022 05:31:04 -0800 (PST) Date: Thu, 29 Dec 2022 22:30:58 +0900 From: Hyeonggon Yoo <42.hyeyoo@gmail.com> To: Petr Mladek Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin , HORIGUCHI =?utf-8?B?TkFPWUEo5aCA5Y+j44CA55u05LmfKQ==?= , Joe Perches , Andy Shevchenko , Matthew WilCox , David Hildenbrand , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC v3 3/4] mm, printk: introduce new format %pGt for page_type Message-ID: References: <20221218101901.373450-1-42.hyeyoo@gmail.com> <20221218101901.373450-4-42.hyeyoo@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: A159320018 X-Stat-Signature: ptup3krufdarkx1z58jbp7bqcktqirxh X-HE-Tag: 1672320666-811579 X-HE-Meta: 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 IyEulYW5 tS0tlZGqgDcrIVF7sPnizX+sHtVUn6ZQCM8d8yfdJbVIEn+/zyE86xRMoNI5z96C0tZW83ykghdEAvZDebwRclYO8dfUYtYNxjw5h6vXPyAlRqZ0+rXS+NtFtnWoa9WQoiK4Kb3uUHhciAvlcg0daoUhS3p/csTEg0bpmpxcdHuo568I= 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 Tue, Dec 20, 2022 at 04:20:26PM +0100, Petr Mladek wrote: > On Sun 2022-12-18 19:19:00, Hyeonggon Yoo wrote: > > %pGp format is used to print 'flags' field of struct page. > > As some page flags (e.g. PG_buddy, see page-flags.h for more details) > > are set in page_type field, introduce %pGt format which provides > > human readable output of page_type. > > > > Note that the sense of bits are different in page_type. if page_type is > > 0xffffffff, no flags are set. if PG_slab (0x00100000) flag is set, > > page_type is 0xffefffff. Clearing a bit means we set the bit. > > > > Bits in page_type are inverted when printing page type names. > > > > --- a/Documentation/core-api/printk-formats.rst > > +++ b/Documentation/core-api/printk-formats.rst > > @@ -575,12 +575,13 @@ The field width is passed by value, the bitmap is passed by reference. > > Helper macros cpumask_pr_args() and nodemask_pr_args() are available to ease > > printing cpumask and nodemask. > > > > -Flags bitfields such as page flags, gfp_flags > > +Flags bitfields such as page flags, page_type, gfp_flags > > --------------------------------------------- > > Please, underline the entire title. Otherwise, "make htmldoc" > complains ;-) > > /prace/kernel/linux/Documentation/core-api/printk-formats.rst:579: WARNING: Title underline too short. > Flags bitfields such as page flags, page_type, gfp_flags Still not getting used to rst format ;) Will fix, thanks! > > > > > > :: > > > > %pGp 0x17ffffc0002036(referenced|uptodate|lru|active|private|node=0|zone=2|lastcpupid=0x1fffff) > > + %pGt 0xffefffff(slab) > > %pGg GFP_USER|GFP_DMA32|GFP_NOWARN > > %pGv read|exec|mayread|maywrite|mayexec|denywrite > > > > Please, explain this also in the paragraph below these examples. > I would personally refactor it to an itemized list, something like: > > > For printing flags bitfields as a collection of symbolic constants that > would construct the value. The type of flags is given by the third > character. Currently supported are: > > - p - [p]age flags, expects value of type (``unsigned long *``) > - t - page [t]ype, expects value of type (``unsigned int *``) > - v - [v]ma_flags, expects value of type (``unsigned long *``) > - g - [g]fp_flags, expects value of type (``gfp_t *``) > > The flag names and print order depends on the particular type. > The proposal sounds reasonable to me, will adjust in next version. > Rant: > Sigh, it looks a bit error prone when similar pointer modifiers > expects pointers to different types. I wish there was a way how > to check the passed pointer type at compilation time. But it > is generic problem with these %p* modifiers. >From my limited knowledge, it seems that there is no way to check this :/ > > Otherwise the patch looks fine for the vsprinf side. Thank you for looking at this! > > Best Regards, > Petr -- Thanks, Hyeonggon