From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="WcLAhtgR" Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D53610C; Tue, 21 Nov 2023 06:47:28 -0800 (PST) Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3ALEk3tm014458; Tue, 21 Nov 2023 14:47:23 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=pp1; bh=Il+3Zk9hp5HPXXvA6SgYAW5XlRe/3nnrw4Xtqs9gj+s=; b=WcLAhtgRSqWuIUjUe6hNEbSxxML1cgZRGZ9SlhP9+p1EpwIP2wvAgJm9DDUTEuragW2o /8hm2vq9iEqx77qFYqA+A1HVdog+2V2Kg8761iLqayTfzz5DtpxM/gX+oixh76thfewy kloOCZ5InDfPvKgdlaE5vbT/R7Ok6lrzV6mgX69KbvwU1uqMj0g6g9RJ1qOfQIq4TYqZ 8lFBJciMhFv/t3X8pNBaMUNJnDZbL2iflj6C3SA6oRKdTf2fp6QalFrinVTYKGVIaXLj NJpD/HJryPYqGsi2oJ9bFshLF9RaPX9QZ6sheFx0FFFUsedGeQwnYd932PvqQWdHYN9M Pg== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3ugxkn013y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 21 Nov 2023 14:47:23 +0000 Received: from m0360072.ppops.net (m0360072.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3ALEl31K017203; Tue, 21 Nov 2023 14:47:22 GMT Received: from ppma13.dal12v.mail.ibm.com (dd.9e.1632.ip4.static.sl-reverse.com [50.22.158.221]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3ugxkn013g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 21 Nov 2023 14:47:22 +0000 Received: from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1]) by ppma13.dal12v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 3ALDnIUM024887; Tue, 21 Nov 2023 14:47:21 GMT Received: from smtprelay04.fra02v.mail.ibm.com ([9.218.2.228]) by ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 3uf9tk8vw9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 21 Nov 2023 14:47:21 +0000 Received: from smtpav06.fra02v.mail.ibm.com (smtpav06.fra02v.mail.ibm.com [10.20.54.105]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 3ALElIiG29032798 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 21 Nov 2023 14:47:19 GMT Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D677E2004D; Tue, 21 Nov 2023 14:47:18 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B4D9A2004F; Tue, 21 Nov 2023 14:47:18 +0000 (GMT) Received: from osiris (unknown [9.152.212.60]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTPS; Tue, 21 Nov 2023 14:47:18 +0000 (GMT) Date: Tue, 21 Nov 2023 15:47:17 +0100 From: Heiko Carstens To: Alexander Gordeev Cc: Vishal Moola , linux-mm@kvack.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Gerald Schaefer Subject: Re: [PATCH] pgtable: do not expose _refcount field via ptdesc Message-ID: <20231121144717.6318-A-hca@linux.ibm.com> References: <20231121120310.696335-1-agordeev@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231121120310.696335-1-agordeev@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: RTfch-c1H22NI79LYQCs1Wnt6Z8SobN_ X-Proofpoint-GUID: fiBSlMlH0We5yBP55yGtCmvKv_vNJ-za X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-21_07,2023-11-21_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1011 lowpriorityscore=0 suspectscore=0 impostorscore=0 mlxscore=0 priorityscore=1501 mlxlogscore=811 adultscore=0 malwarescore=0 spamscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2311210115 On Tue, Nov 21, 2023 at 01:03:10PM +0100, Alexander Gordeev wrote: > Since commit d08d4e7cd6bf ("s390/mm: use full 4KB page for 2KB PTE") > _refcount field is not used for fragmented page tracking on s390 and > there is no other code left that accesses this field explicitly. > > Suggested-by: Heiko Carstens > Signed-off-by: Alexander Gordeev > --- > include/linux/mm_types.h | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 957ce38768b2..0330e0ddca11 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -401,11 +401,10 @@ FOLIO_MATCH(compound_head, _head_2a); > * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs. > * @__page_mapping: Aliases with page->mapping. Unused for page tables. > * @pt_mm: Used for x86 pgds. > - * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only. > + * @pt_frag_refcount: For fragmented page table tracking. Powerpc only. > * @_pt_pad_2: Padding to ensure proper alignment. > * @ptl: Lock for the page table. > * @__page_type: Same as page->page_type. Unused for page tables. > - * @_refcount: Same as page refcount. Used for s390 page tables. I would guess that you need to describe _pt_pad_3 instead here, just like it is done for the other two pad members. And most likely you need to add Andrew to "To:" so he doesn't miss this :)