From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) (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 E43852135A2; Thu, 20 Feb 2025 18:02:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740074576; cv=none; b=ZPVUi0a8glyi4xVYs+d/XU2yJCmDReAM1TuEXmtGytlUgnUfUaDZjEsWeBjxDGPxYcxcZEDKKr/k6WdEBp45Df89pwdT9Igge7U9V+aiCVnZlfhjUBjQbFzH09yVs2eamcajmr9vgPEVpd39uFwgcWU54xbmH59dRjjxk2i+fx0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740074576; c=relaxed/simple; bh=CUChw1zpKX1czFg5QtOhwWs6v9dQ8q/Dvl9QBfBP5/0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GZzz28ba9iv83zKcARWDMWzm2zWOljzulKD7Kp3ZTAXdBWyGlVZWo47VfjsgaOAZ39sQACZwpzVXADLq6oVq1sJKoSdOnzFTDqG2dNTrjUNlAw8tm6ZxRXAh4L1UyVidX/6lBak5qw+PCDDiUIt4nCnj/zspxxgIFSPoTm1LUDA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=a0sbsXDK; arc=none smtp.client-ip=198.175.65.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="a0sbsXDK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1740074575; x=1771610575; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=CUChw1zpKX1czFg5QtOhwWs6v9dQ8q/Dvl9QBfBP5/0=; b=a0sbsXDKXwL8alAjuL0WF145c1UrZkyTjSF6h2kCiuFUdDMO7WhhyBSa t51OCncozUN1gdPZhlC3+YMqrZySYN6YqNYrMpyKpZJaGoeDuXT98hx5Z uWOgovvc/8VXH6EDzHxQyK1IwDwf6lPi4dNmcRoNNYst4KNB3YZR1g8dm Gyq+3kLjPbZ3fnNQpVJe2jtls2vISFhlORY1f9VxBd1LNw4uvP4jNfyo+ kIRdl7E0Y8mEo+n9PVjVvKNJAB1617HN2E+z4N7qUH9SxEJQDSnYgAGb5 dMUOdHuVBbWtVbHfjsfhgyAsV5CMOdEVukFMKU1iHWhaenCEuWA9xRqcy g==; X-CSE-ConnectionGUID: RKrZoccAQ2KLAukXU1xklw== X-CSE-MsgGUID: wrp1g1bzQqOU5Ritco42aA== X-IronPort-AV: E=McAfee;i="6700,10204,11351"; a="63346303" X-IronPort-AV: E=Sophos;i="6.13,302,1732608000"; d="scan'208";a="63346303" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Feb 2025 10:02:54 -0800 X-CSE-ConnectionGUID: W9agr/+RTS6tJSBDtvX1pg== X-CSE-MsgGUID: VDrQa2UqS4KG472jDCWkCw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,302,1732608000"; d="scan'208";a="120219174" Received: from puneetse-mobl.amr.corp.intel.com (HELO [10.125.110.82]) ([10.125.110.82]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Feb 2025 10:02:53 -0800 Message-ID: Date: Thu, 20 Feb 2025 10:02:54 -0800 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] x86/vmemmap: Synchronize with global pgds if populating init_mm's pgd To: Gwan-gyeong Mun , linux-kernel@vger.kernel.org Cc: osalvador@suse.de, 42.hyeyoo@gmail.com, byungchul@sk.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, akpm@linux-foundation.org, stable@vger.kernel.org, linux-mm@kvack.org, max.byungchul.park@sk.com, max.byungchul.park@gmail.com References: <20250220064105.808339-1-gwan-gyeong.mun@intel.com> From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzUVEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gKEludGVsIFdvcmsgQWRkcmVzcykgPGRhdmUuaGFuc2VuQGludGVs LmNvbT7CwXgEEwECACIFAlQ+9J0CGwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEGg1 lTBwyZKwLZUP/0dnbhDc229u2u6WtK1s1cSd9WsflGXGagkR6liJ4um3XCfYWDHvIdkHYC1t MNcVHFBwmQkawxsYvgO8kXT3SaFZe4ISfB4K4CL2qp4JO+nJdlFUbZI7cz/Td9z8nHjMcWYF IQuTsWOLs/LBMTs+ANumibtw6UkiGVD3dfHJAOPNApjVr+M0P/lVmTeP8w0uVcd2syiaU5jB aht9CYATn+ytFGWZnBEEQFnqcibIaOrmoBLu2b3fKJEd8Jp7NHDSIdrvrMjYynmc6sZKUqH2 I1qOevaa8jUg7wlLJAWGfIqnu85kkqrVOkbNbk4TPub7VOqA6qG5GCNEIv6ZY7HLYd/vAkVY E8Plzq/NwLAuOWxvGrOl7OPuwVeR4hBDfcrNb990MFPpjGgACzAZyjdmYoMu8j3/MAEW4P0z F5+EYJAOZ+z212y1pchNNauehORXgjrNKsZwxwKpPY9qb84E3O9KYpwfATsqOoQ6tTgr+1BR CCwP712H+E9U5HJ0iibN/CDZFVPL1bRerHziuwuQuvE0qWg0+0SChFe9oq0KAwEkVs6ZDMB2 P16MieEEQ6StQRlvy2YBv80L1TMl3T90Bo1UUn6ARXEpcbFE0/aORH/jEXcRteb+vuik5UGY 5TsyLYdPur3TXm7XDBdmmyQVJjnJKYK9AQxj95KlXLVO38lczsFNBFRjzmoBEACyAxbvUEhd GDGNg0JhDdezyTdN8C9BFsdxyTLnSH31NRiyp1QtuxvcqGZjb2trDVuCbIzRrgMZLVgo3upr MIOx1CXEgmn23Zhh0EpdVHM8IKx9Z7V0r+rrpRWFE8/wQZngKYVi49PGoZj50ZEifEJ5qn/H Nsp2+Y+bTUjDdgWMATg9DiFMyv8fvoqgNsNyrrZTnSgoLzdxr89FGHZCoSoAK8gfgFHuO54B lI8QOfPDG9WDPJ66HCodjTlBEr/Cwq6GruxS5i2Y33YVqxvFvDa1tUtl+iJ2SWKS9kCai2DR 3BwVONJEYSDQaven/EHMlY1q8Vln3lGPsS11vSUK3QcNJjmrgYxH5KsVsf6PNRj9mp8Z1kIG qjRx08+nnyStWC0gZH6NrYyS9rpqH3j+hA2WcI7De51L4Rv9pFwzp161mvtc6eC/GxaiUGuH BNAVP0PY0fqvIC68p3rLIAW3f97uv4ce2RSQ7LbsPsimOeCo/5vgS6YQsj83E+AipPr09Caj 0hloj+hFoqiticNpmsxdWKoOsV0PftcQvBCCYuhKbZV9s5hjt9qn8CE86A5g5KqDf83Fxqm/ vXKgHNFHE5zgXGZnrmaf6resQzbvJHO0Fb0CcIohzrpPaL3YepcLDoCCgElGMGQjdCcSQ+Ci FCRl0Bvyj1YZUql+ZkptgGjikQARAQABwsFfBBgBAgAJBQJUY85qAhsMAAoJEGg1lTBwyZKw l4IQAIKHs/9po4spZDFyfDjunimEhVHqlUt7ggR1Hsl/tkvTSze8pI1P6dGp2XW6AnH1iayn yRcoyT0ZJ+Zmm4xAH1zqKjWplzqdb/dO28qk0bPso8+1oPO8oDhLm1+tY+cOvufXkBTm+whm +AyNTjaCRt6aSMnA/QHVGSJ8grrTJCoACVNhnXg/R0g90g8iV8Q+IBZyDkG0tBThaDdw1B2l asInUTeb9EiVfL/Zjdg5VWiF9LL7iS+9hTeVdR09vThQ/DhVbCNxVk+DtyBHsjOKifrVsYep WpRGBIAu3bK8eXtyvrw1igWTNs2wazJ71+0z2jMzbclKAyRHKU9JdN6Hkkgr2nPb561yjcB8 sIq1pFXKyO+nKy6SZYxOvHxCcjk2fkw6UmPU6/j/nQlj2lfOAgNVKuDLothIxzi8pndB8Jju KktE5HJqUUMXePkAYIxEQ0mMc8Po7tuXdejgPMwgP7x65xtfEqI0RuzbUioFltsp1jUaRwQZ MTsCeQDdjpgHsj+P2ZDeEKCbma4m6Ez/YWs4+zDm1X8uZDkZcfQlD9NldbKDJEXLIjYWo1PH hYepSffIWPyvBMBTW2W5FRjJ4vLRrJSUoEfJuPQ3vW9Y73foyo/qFoURHO48AinGPZ7PC7TF vUaNOTjKedrqHkaOcqB185ahG2had0xnFsDPlx5y In-Reply-To: <20250220064105.808339-1-gwan-gyeong.mun@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/19/25 22:41, Gwan-gyeong Mun wrote: > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 01ea7c6df303..7935859bcc21 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -1498,6 +1498,54 @@ static long __meminitdata addr_start, addr_end; > static void __meminitdata *p_start, *p_end; > static int __meminitdata node_start; > > +static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node) > +{ > + void *p = vmemmap_alloc_block(size, node); > + > + if (!p) > + return NULL; > + memset(p, 0, size); > + > + return p; > +} This is a pure copy and paste of the generic function. I assume this is because the mm/sparse-vmemmap.c is static. But this kind of copying is really unfortunate. ... > +pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node) > +{ > + pgd_t *pgd = pgd_offset_k(addr); > + > + if (pgd_none(*pgd)) { > + void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node); > + > + if (!p) > + return NULL; > + > + pgd_populate(&init_mm, pgd, p); > + sync_global_pgds(addr, addr); > + } > + > + return pgd; > +} I'd _really_ like to find another way to do this. We really don't want to add copy-and-paste versions of generic functions that we now need to maintain on the x86 side. The _best_ way is probably to create some p*d_populate_kernel() helpers: void pgd_populate_kernel(unsigned long addr, pgd_t *pgd, p4d_t *p4d) { pgd_populate(&init_mm, pgd, p4d); arch_sync_global_pgds(addr, addr+something); } and move over most of the callers of: p*d_populate(&init_mm, ...); Because I suspect that'll fix your issue _and_ solve the generic class of issues where folks populate a kernel page table entry but forget to call sync_global_pgds().