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 B98ACEB64D0 for ; Tue, 13 Jun 2023 13:49:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 11EB68E0007; Tue, 13 Jun 2023 09:49:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0CF4A8E0003; Tue, 13 Jun 2023 09:49:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EB1AC8E0007; Tue, 13 Jun 2023 09:48:59 -0400 (EDT) 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 DB5888E0003 for ; Tue, 13 Jun 2023 09:48:59 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 938CAA04C8 for ; Tue, 13 Jun 2023 13:48:59 +0000 (UTC) X-FDA: 80897855598.01.476644D Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf12.hostedemail.com (Postfix) with ESMTP id 5A59D4001C for ; Tue, 13 Jun 2023 13:48:56 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b=JVMHh2vb; dmarc=pass (policy=none) header.from=ibm.com; spf=pass (imf12.hostedemail.com: domain of aneesh.kumar@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=aneesh.kumar@linux.ibm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1686664137; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=sR3cA5jcgM3zbkMG0BS3rDJTh1ZhaC9GdSgROfqp8yY=; b=U4C2ZF641AG3f2DXzvd6YXntDlxm2kM5SgMXTnAWIqwObTDyG3OYk5LXxMQXawmCmyDh7C n1YAk4hm4rmzg8XfIkIOSn2pQCzUdiJ0cZPSbIKN3SoXX333qh7YPYBsSPlYwv4PK3UXDs F5E8Bp1eEY+PLzsrQA2zgsT8S1/LLuI= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b=JVMHh2vb; dmarc=pass (policy=none) header.from=ibm.com; spf=pass (imf12.hostedemail.com: domain of aneesh.kumar@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=aneesh.kumar@linux.ibm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1686664137; a=rsa-sha256; cv=none; b=ketPrauUrkphnA3njO1U8+Yn1qLPWe8RJXHHY9+MAtIf/uYO7ege8Qbdj9fRuaZmLbwhJK CNX63JefI8srIpOYuzFQkiBu4SMcRIGEWoCU2bQ+xQ5KGzDoTtT8xNzcz0kdInkxrW2vft 4KVG6GjsgeP8wco5u2ae14YTFtgPyNU= Received: from pps.filterd (m0356517.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 35DDlCXK007988; Tue, 13 Jun 2023 13:48:52 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=sR3cA5jcgM3zbkMG0BS3rDJTh1ZhaC9GdSgROfqp8yY=; b=JVMHh2vbRnF8/NKiEzSXyZ0d4wGeCtacaVsIXAY5s5zaoYmzpERpu/ep8hesP302boxy 5jPQcWApvrIBemYT1GmPUXyo9Gad1pqHBmwW229FauhEvNuf5jaa5Nw0nb5YkkCIBfVX JxxZiimL4a7A5Pzd9uL6GAnPgpuiuuiozKv5A8YxJIAgwsRMJrLwoH9BQcFbwGFi90cv wMTngeOjzFJtELxYtq82jLrEKPDj12T1HN9F6GgpLTqfgUSbCEzKjtFqpYXOItJ1lpk+ XQnoj6+4YhZShtZJWHFUpbcIrWz0kfUWm1/0+YyaB9MZQBhznhpYboOLlH1MvhZwvnzx RA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3r6s9a8j59-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 13 Jun 2023 13:48:52 +0000 Received: from m0356517.ppops.net (m0356517.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 35DDlFcP008754; Tue, 13 Jun 2023 13:48:16 GMT Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3r6s9a8e9b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 13 Jun 2023 13:48:15 +0000 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 35DDjKN6023702; Tue, 13 Jun 2023 13:47:23 GMT Received: from smtprelay03.fra02v.mail.ibm.com ([9.218.2.224]) by ppma03fra.de.ibm.com (PPS) with ESMTPS id 3r4gt51mry-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 13 Jun 2023 13:47:22 +0000 Received: from smtpav05.fra02v.mail.ibm.com (smtpav05.fra02v.mail.ibm.com [10.20.54.104]) by smtprelay03.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 35DDlKYX40763690 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 13 Jun 2023 13:47:20 GMT Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 628FB2004F; Tue, 13 Jun 2023 13:47:20 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1B09C20043; Tue, 13 Jun 2023 13:47:19 +0000 (GMT) Received: from [9.43.61.208] (unknown [9.43.61.208]) by smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 13 Jun 2023 13:47:18 +0000 (GMT) Message-ID: Date: Tue, 13 Jun 2023 19:17:18 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH 3/3] mm/lru_gen: Don't build multi-gen LRU page table walk code on architecture not supported Content-Language: en-US To: Matthew Wilcox Cc: linux-mm@kvack.org, akpm@linux-foundation.org, Yu Zhao , "T . J . Alumbaugh" References: <20230613120047.149573-1-aneesh.kumar@linux.ibm.com> <20230613120047.149573-3-aneesh.kumar@linux.ibm.com> From: Aneesh Kumar K V In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 3chIK39edfDFQoSQFuOfpkeV5YiFCYIr X-Proofpoint-ORIG-GUID: f0Hx4WMwvax4MtTu5SMzcQmLv6JVG0xx X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26 definitions=2023-06-13_04,2023-06-12_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 suspectscore=0 adultscore=0 clxscore=1015 mlxlogscore=808 spamscore=0 priorityscore=1501 lowpriorityscore=0 bulkscore=0 mlxscore=0 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2306130119 X-Rspamd-Queue-Id: 5A59D4001C X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: a8a85h1p8k76b4o3e67d51i6kzymqxes X-HE-Tag: 1686664136-683684 X-HE-Meta: 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 DzmT2Poo O/RozpKjqpG+cyzuzgRv9BQIY9R8r5M60BCzQkLJGfdMcFDTzqePZ6neP/AL3gr8dDr2ssBuk4Him6zUyXFxCgjmFtrMKBspMBXoW3QLWatz4sZc3Q88FypfIcH4IwqDX/AKXKYVBd2PkTXT5HhyunHL81BDADVWSjjWLXCddW9Qb5x8= 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 6/13/23 7:06 PM, Matthew Wilcox wrote: > On Tue, Jun 13, 2023 at 06:58:41PM +0530, Aneesh Kumar K V wrote: >> On 6/13/23 5:53 PM, Matthew Wilcox wrote: >>> On Tue, Jun 13, 2023 at 05:30:47PM +0530, Aneesh Kumar K.V wrote: >>>> @@ -4498,7 +4533,7 @@ static bool try_to_inc_max_seq(struct lruvec *lruvec, unsigned long max_seq, >>>> goto done; >>>> } >>>> >>>> - walk = set_mm_walk(NULL, true); >>>> + walk = (struct lru_gen_mm_walk *)set_mm_walk(NULL, true); >>> >>> This isn't C++. >>> >> >> We have similar pattern for things like kmalloc()? > > No. No, we don't. Nobody does that. Perhaps some really crappy code > in staging. DO NOT USE CASTS. > >> I understand the desire to have functions return >> the correct type. But the amount of code that we are able to avoid with this patch for certain architecture is >> really large. > > There's probably a better way to do what you're trying to do, but the > simple fact remains that the cast you added is needed in C++ and not in C. > Linux is not written in C++. Do not add the cast. What I want is to allow the usage of set_mm_walk() such that i don't need to have that #ifdef throughout the code. I also want to keep the definition of struct lru_gen_mm_walk {} within that #ifdef as below. #ifdef CONFIG_LRU_TASK_PAGE_AGING struct lru_gen_mm_walk { /* the lruvec under reclaim */ ... }; static void *set_mm_walk(struct pglist_data *pgdat, bool force_alloc) { struct lru_gen_mm_walk *walk = current->reclaim_state->mm_walk; ... return walk; } #else static inline void *set_mm_walk(struct pglist_data *pgdat, bool force_alloc) { return NULL; } #endif