From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83F6E3FBEA5 for ; Wed, 8 Jul 2026 08:02:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783497725; cv=none; b=P3AgJCV9iOdRsJiNcQQKH0SMzfvy6LTsNmBwITdAU2TSfckxYsj/RlWWV2AXfKsEM2cUYhkAqd/CoYuvMyDziuARWt3FqtYBQx7pDJr/0nuI9p4W2UcvlTOM10sO80V4q6DJGpSnx8AmsO1W124yvENI9BN+Dzmxn2OfPuK4NxU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783497725; c=relaxed/simple; bh=70PXKAYBIwbEV3xl+rFK1M0PSvk5j7rGrJcHtozil7k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nCC90hJ99Cz0nB2we4jTARAy2h1JpIenlnjSrDqq2gLbsT79/lkw/ah2Ul4oSh2fNLO6nC7kNEXoffGLS1nEn+2k0XGVneqcyNe2qGAXXn5RA9w4zAFX3c+nEnwWhkeF2/NmaGtK9DhKfYEtJO5Ve6cbDBT43IYmgVgF+v0PVCM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=anY9iFvV; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="anY9iFvV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 823F21F000E9; Wed, 8 Jul 2026 08:01:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783497721; bh=fbC2R2B/TJoZXvgq7yPBJZuA/UIk/LBDKVBSzpYKJWQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=anY9iFvV+9Pi7h4zJsJ8hfBbZmFlrbD8v0wa+xxwMM+w0xEnlPZZXUNCSs0asISWt wYLf9KT6zqc1EKvKwKkTRfVCTc9koejZG+cld52PacRzqffUCOluc3Kr5Ve/4aps0n k2DVw225WHKpyOhvNr3cHyj61B/jxQf06AayZWEyf0Bc30US21ppUmrsxCHwSWlkG6 ip2Wl5W/rtGgh0SCwfpvEsQN7j2VRAe6pSaYwGI/5y+Wm04XySNjJb6RUngBsMDpJs 20AZzkrpgToSUWmVr0wsemc9PdNW+4ZKwlcYeNV2gTRSzK9+9edjDohhSRCR5AfhqG jjhgiLFK4ZONg== Message-ID: <876c533f-6709-43a0-8595-143a8b9c9201@kernel.org> Date: Wed, 8 Jul 2026 10:01:57 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V2] mm: Standardize printing for pgtable entries To: Anshuman Khandual , linux-mm@kvack.org Cc: andriy.shevchenko@linux.intel.com, usama.arif@linux.dev, hughd@google.com, willy@infradead.org, ryan.roberts@arm.com, Andrew Morton , linux-kernel@vger.kernel.org References: <20260708032824.969752-1-anshuman.khandual@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/8/26 05:28, Anshuman Khandual wrote: > From: "David Hildenbrand (Arm)" > > Bad page map reporting currently stores page table entry values in an > unsigned long long and prints them with fixed 64-bit-oriented format > strings. This is inconsistent across call sites and does not work well for > architectures where page table entry values are not naturally represented > as 64-bit values, such as 32-bit or 128-bit entries. > > Introduce a common helper to convert raw page table entry values into a > fixed-width hexadecimal string based on the actual entry size. Use it for > bad page map reporting and for dumping the page table walk in > __print_bad_page_map_pgtable(). > > Pass page table entry values to the reporting path as raw bytes together > with their size, instead of forcing them through an unsigned long long. > It keeps the printed output consistent and avoids truncation or misleading > formatting for non-64-bit page table entries. > > Cc: Andrew Morton > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: David Hildenbrand (Arm) I still think you should add your Co-developed-by :) > Signed-off-by: Anshuman Khandual > --- > This patch applies on v7.2-rc2 > > Changes in V2: > > - Dropped space after ":" during print per Matthew > - Dropped CONFIG_CPU_BIG_ENDIAN per David > > Changes in V1: > > https://lore.kernel.org/all/20260707041703.658021-1-anshuman.khandual@arm.com/ > > mm/memory.c | 98 ++++++++++++++++++++++++++++++++++++++++------------- > 1 file changed, 75 insertions(+), 23 deletions(-) > In general, LGTM (I wrote of it, lol) > diff --git a/mm/memory.c b/mm/memory.c > index ff338c2abe92..a2b63af82792 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -519,9 +519,48 @@ static bool is_bad_page_map_ratelimited(void) > return false; > } > > +#define PTVAL_STR_MAX (32 + 1) /* Max 128-bit value in hex + NUL */ We could reduce the stack space for !__SIZEOF_INT128__, but not sure if worth it. __print_bad_page_map_pgtable() will currently consume 132 bytes for strings, guess that's still tolerable. -- Cheers, David