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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2040DC531FA for ; Fri, 24 Jul 2026 15:49:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Wpu1gJe0sM1zpg7qn6uKI6n3VZyrOevD5zqeBPXBfwE=; b=rLGA9Zq7lTyFqmeLgo/+aWQa+Q e5Oiy7lZIE854FqSay2GYJPZYLLTEy1jzLuHqZjbA/dCAnysKBOV+KENlJMN5EkWXio5oyNSaR2Xk yDw0aLu0of4l0JAK6YyZohC64U1HfLQqKvluuiDRQgnTfsodbymd0qNo0MoCRvhK55ovI+WcUG3WZ 7zoU21nW59kNmQD+7cviGvQrhzYJYMK1qkfaquPpo4g49MhjHKtDlvJBatNFjDjNLv0A5eEb7sywb xsVwJHR1atoCQJmkmQZ1rAAapUCqAP4nrFFzE3m4x0r5cJHo3XHE1ksRqip0nEDBv2zOa/PLYFltN 6o0MEAuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wnI91-0000000Gl3V-3mI7; Fri, 24 Jul 2026 15:49:03 +0000 Received: from out-170.mta0.migadu.com ([2001:41d0:1004:224b::aa]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wnI8z-0000000Gl2U-1XrO for linux-arm-kernel@lists.infradead.org; Fri, 24 Jul 2026 15:49:03 +0000 Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1784908138; h=from:from: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; bh=Wpu1gJe0sM1zpg7qn6uKI6n3VZyrOevD5zqeBPXBfwE=; b=Nwts4fjdNhRkKoiWWgZb1pTyJfagzBgyAnhKRuaoRCtBx7aSslbqFtzy/tsaZj6SPePbPj +h8333InKBjxMVvWvd3VZk65pWaNGEHdIfYDP0nvTh3PcpkutNlEUvY2oMMCgrEm5Igfrr HnNV1rKdfXh4xzFXjakZOI0RjFHt+wk= Date: Fri, 24 Jul 2026 16:48:50 +0100 MIME-Version: 1.0 Subject: Re: [PATCH 3/5] mm/parisc: constify ptep_get() argument To: Pedro Falcato Cc: Matthew Wilcox , Andrew Morton , David Hildenbrand , Catalin Marinas , Will Deacon , "James E.J. Bottomley" , Helge Deller , Madhavan Srinivasan , Michael Ellerman , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jan Kara , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Kevin Brodsky , Muhammad Usama Anjum , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org References: <20260724102017.141532-1-pfalcato@suse.de> <20260724102017.141532-4-pfalcato@suse.de> <0fd713a8-e4ab-4c07-b36e-79dd138b4a86@linux.dev> <253f7ac0-205b-42f1-9fb5-d19eceb581b6@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Usama Arif In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260724_084901_553555_B9493946 X-CRM114-Status: GOOD ( 19.01 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 24/07/2026 16:32, Pedro Falcato wrote: > On Fri, Jul 24, 2026 at 04:03:44PM +0100, Usama Arif wrote: >> >> >> On 24/07/2026 15:14, Matthew Wilcox wrote: >>> On Fri, Jul 24, 2026 at 02:36:59PM +0100, Usama Arif wrote: >>>> >>>> >>>> On 24/07/2026 11:20, Pedro Falcato wrote: >>>>> ptep_get() does not need write access to the PTE. >>>>> >>>>> Signed-off-by: Pedro Falcato >>>>> --- >>>>> arch/parisc/include/asm/pgtable.h | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>> hmm I think you might break build bisectibility if >>>> you separate out the patches, you should squash patch 3 and 4, >>>> with patch 1. >>> >>> I don't see how this breaks bisectability. Can you elaborate on what >>> you think would break? >> >> Patch 1 does: >> >> -static inline pte_t ptep_get_lockless(pte_t *ptep) >> +static inline pte_t ptep_get_lockless(const pte_t *ptep) >> { >> return ptep_get(ptep); >> } >> >> >> ptep_get() takes a non-const arg till patch 3 for example for parsic. >> I don't think you can pass a const variable to non const function arg? >> >> So parsic won't compile in patch 1 and 2, powerprc wont compile >> for patches 1, 2 and 3.. > > Aha, yes, nice catch! I'll have to rethink that. Maybe squashing the patches > would be the cleanest way forward. > Yes, squashing is the simplest way forward. > FWIW, the vast majority of architectures aren't doing funny things on > ptep_get(). E.g PA-RISC, loongarch only define these so they can use it in > their own asm/pgtable.h. I'd really like to delete these but I can't tell > if they are *actually* required. > Ah maybe there is something in git history on why it was needed? If not, hopefully someone from the arch lists could clarify.. > With those gone only PPC 8xx and generic would need to be squashed (arm64 also > defines its own version of ptep_get_lockless()). > >