From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3464772630; Mon, 27 Jul 2026 18:06:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785175600; cv=none; b=TQB0doGaNepz1cmFlTJ9PC8yBIR3vhgxTalDlv/D/PoY9cC0q4/dYw5H4gowJ7EjqEp4IyRXekZ37JWF49Kx7PUhcPHg1DVhrAiOxeFFnwhqkj34yxo+ZkM28MYAYt2GcW48tDyL/EPjUY0xpDTQl4fzH2URrLuc/UikLUWSdUE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785175600; c=relaxed/simple; bh=17fUHUjXNeVWMgUSlC4I4UbGJCuscyMxz/0B2wiLID0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RK+9NLDrVCljYwtd8r5SlzpkJowg8wUCS87OAQpLwgbKz3DIGdxQEFEzFi1dQUz7DzAlg8O6xLkkuw1Ur5fKlKZW5H3ZkL6i+AEensxM9GAnZcLzNkkmCGQEGC+GQYgPBVm7p9FMi9+KBOPk6oewnFiNmejpfCbKE03RSEKbTzE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=Lu1jXBGs; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="Lu1jXBGs" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 659AD1688; Mon, 27 Jul 2026 11:06:34 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 380273F86F; Mon, 27 Jul 2026 11:06:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785175598; bh=17fUHUjXNeVWMgUSlC4I4UbGJCuscyMxz/0B2wiLID0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Lu1jXBGsav0iVgrGWSZsvRyAlJ5at2QxNHv1w1hXfz5ioFXzND+YJHKyFrA03qRFY Q/hx54v2Cd4KFrZuJPBBE4RftgYfvLs49KTQX5Dz6eKnnAQEbcQ/tI+05OTQ1z0zkD i2PqFVr45Lxp9zCvG4+AVFaAlSVytmKw9arVF48g= Date: Mon, 27 Jul 2026 19:06:29 +0100 From: Yeoreum Yun To: "David Hildenbrand (Arm)" Cc: Yeoreum Yun , Dave Hansen , Russell King , Huacai Chen , WANG Xuerui , Thomas Bogendoerfer , Catalin Marinas , Will Deacon , Arnd Bergmann , Andrew Morton , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Johannes Weiner , Michal Hocko , Lorenzo Stoakes , Tianrui Zhao , Bibo Mao , Anup Patel , Atish Patra , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonas Bonn , Stefan Kristiansson , Stafford Horne , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-openrisc@vger.kernel.org Subject: Re: [PATCH RFC v2 12/20] x86: mm: define pudp_set_access_flags() when CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD is enabled only. Message-ID: References: <20260722-dummy_ptxp3-v2-0-d9e4bad31e0a@arm.com> <20260722-dummy_ptxp3-v2-12-d9e4bad31e0a@arm.com> <188623a9-dba0-4229-a7ff-5feb2ef0c088@intel.com> <4dbf7e54-a541-45de-b4b9-43ee5add287b@kernel.org> Precedence: bulk X-Mailing-List: linux-mips@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: <4dbf7e54-a541-45de-b4b9-43ee5add287b@kernel.org> On Mon, Jul 27, 2026 at 05:02:00PM +0200, David Hildenbrand (Arm) wrote: > On 7/22/26 19:27, Yeoreum Yun wrote: > > Hi Dave, > > > >>> diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c > >>> index f32facdb3035..edad847a2ecd 100644 > >>> --- a/arch/x86/mm/pgtable.c > >>> +++ b/arch/x86/mm/pgtable.c > >>> @@ -411,6 +411,7 @@ int pmdp_set_access_flags(struct vm_area_struct *vma, > >>> return changed; > >>> } > >>> > >>> +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD > >>> int pudp_set_access_flags(struct vm_area_struct *vma, unsigned long address, > >>> pud_t *pudp, pud_t entry, int dirty) > >>> { > >>> @@ -430,6 +431,7 @@ int pudp_set_access_flags(struct vm_area_struct *vma, unsigned long address, > >>> > >>> return changed; > >>> } > >>> +#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ > >>> #endif > >>> > >>> bool ptep_test_and_clear_young(struct vm_area_struct *vma, > >> > >> #ifdefs in .c files are evil. > >> > >> The changelog doesn't make a strong enough case for why this evil should > >> be tolerated. > >> > >> These are also _precisely_ the kind of #ifdefs that cause compilation > >> problems. This one is: > >> > >> #ifdef CONFIG_TRANSPARENT_HUGEPAGE > >> /// function here > >> #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD > >> /// another function here > >> #endif > >> #endif > >> > >> So there end up being a couple of dependent config options in play. If > >> there are compile problems, this makes them harder to find. > >> > >> What is the _actual_ goal here? Saving 50 bytes of kernel text? > > > > TBH, this came from for v1's change of behavior set_pud() where > > triggered compiliation problem with v2 this change wouldn't require. > > If the patch is not required right now, let's drop it. > > I agree that it's the right thing to do: just look at pudp_invalidate() in the > very same file, but if we can reduce the churn and leave the cleanups to x86 > folks, that seems to be preferred. Yes. I'll drop in next version. -- Sincerely, Yeoreum Yun