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 02C4CC28B2E for ; Tue, 11 Mar 2025 05:27:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 329D3280002; Tue, 11 Mar 2025 01:27:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2B4DC280001; Tue, 11 Mar 2025 01:27:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1606F280002; Tue, 11 Mar 2025 01:27:47 -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 E89D7280001 for ; Tue, 11 Mar 2025 01:27:46 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id A4BD71CCA38 for ; Tue, 11 Mar 2025 05:27:47 +0000 (UTC) X-FDA: 83208138174.02.34DFC7B Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf02.hostedemail.com (Postfix) with ESMTP id F1E8C80014 for ; Tue, 11 Mar 2025 05:27:45 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=GAHpdUKS; spf=pass (imf02.hostedemail.com: domain of rppt@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1741670866; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=1LtqkvatmL8zEprV8JDrvPTk9OulcQe853ibSUZCYUc=; b=SO+VAP2nIDyQwZl4VvXJFy6KqyiVMva+xmlRGmDj/eGdLPF2H43RE6+Gfxfhm8sPF1C1aK PWCZG60PFl5KJEmuGHawB1lwdbVtBl6AzrN3y34aSZtjswQLNexmC268zcJrvapOWnnGQ4 Lp9WSLuks60BulOyuOy4QLtYUdCEV/c= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=GAHpdUKS; spf=pass (imf02.hostedemail.com: domain of rppt@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1741670866; a=rsa-sha256; cv=none; b=Tj++lxKcGuIKDxenQwiNwoE9FzcpsM/weRfLjEy3Is8mC4/Uf7HeafW9BBobIIveV3Ev6A 6DFgoRNmzGCD6FaupTq7RjQRrNnzLKwoAZM52JRHdMl0bU+pHALsSfCr6xzS3b+1ZSamrD vBpVDVC8GBOYASS9AW/hgvYSDXHOdaA= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id C2F1CA46861; Tue, 11 Mar 2025 05:22:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ACB76C4CEEC; Tue, 11 Mar 2025 05:27:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741670864; bh=6FrJToULI5AieC/xcPkMqRkdPc73MU/g7qUb/+Gf2LU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GAHpdUKSmv1QM82YGoNX6ldSWprWPtoQeq7oZVYRSenmRL5V3mQA0Z/8J1J7rkbXY DCZ1PolWSm96XtMjC6zHeV/4BIYLkdQBd+2LSkhUUHx/NvSeQhtKi3xVRFBvvahBI6 Fgecu8QW9SZnOgCJFzyGzUd8oW5EhoPWaTHjItebVqj/yACpIkHUi3606UEwiKBAbx 3YfDwolecrwr/CHlFMVtqpXQ8QtwdePj5lo049ABQgMlHqkjpQCaCVHGRbh/9KJaaJ GKa8u7BRKr01NRTAB8Jp1oImuXWXsRmL8WzrwbdwZpVY+aPZzBz/SBsDbDXNSbRoaJ K0Cd6UgpZbrJA== Date: Tue, 11 Mar 2025 07:27:23 +0200 From: Mike Rapoport To: Wei Yang Cc: linux-kernel@vger.kernel.org, Alexander Graf , Andrew Morton , Andy Lutomirski , Anthony Yznaga , Arnd Bergmann , Ashish Kalra , Benjamin Herrenschmidt , Borislav Petkov , Catalin Marinas , Dave Hansen , David Woodhouse , Eric Biederman , Ingo Molnar , James Gowans , Jonathan Corbet , Krzysztof Kozlowski , Mark Rutland , Paolo Bonzini , Pasha Tatashin , "H. Peter Anvin" , Peter Zijlstra , Pratyush Yadav , Rob Herring , Rob Herring , Saravana Kannan , Stanislav Kinsburskii , Steven Rostedt , Thomas Gleixner , Tom Lendacky , Usama Arif , Will Deacon , devicetree@vger.kernel.org, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Subject: Re: [PATCH v4 02/14] memblock: add MEMBLOCK_RSRV_KERN flag Message-ID: References: <20250206132754.2596694-1-rppt@kernel.org> <20250206132754.2596694-3-rppt@kernel.org> <20250218155004.n53fcuj2lrl5rxll@master> <20250223002229.xuk6xlp23zr72hkc@master> <20250310095124.pa7dwgqhxglqrfes@master> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250310095124.pa7dwgqhxglqrfes@master> X-Rspam-User: X-Rspamd-Queue-Id: F1E8C80014 X-Rspamd-Server: rspam03 X-Stat-Signature: hw5ae9ra3xrqaioqn7tsmprtcjcerkf3 X-HE-Tag: 1741670865-648491 X-HE-Meta: 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 vdJFdcK+ cchE/yoaU8WXqiC6slMTrSHIAC1Qo7gOeZzJ7yK+SD9zE/7f6wo0fiwlw+2OMcNDnDmmEKdTzDlrMrZplyjY4Uo54GRczIoWaSeTa/il7N9qK6g4iq1irf110F8pFfXTA9d/cxhTEed5M4j9WJtlscuLtZDVg9+PNAyHS4URWVTvy921p/8J12bvyxrlhHp7uMpruTp2CVd1DmAwl7Ki9jXcsrmLJPk7q9kh+1mfY33GqJOxDKXxkZgftqOqSbuTTxp1sa4Wv++9LGzM3u0l1H0brBZ6SocP7Wum8BXe5rSgdMXzMMpqVvtOYWrxL9oIs+hIFvAXm71Zbey5JBcZWBW4Qho5xB1tngiryWvmFC5YGtnJRkN6LPzTMGBHOhoxcRaxt36GtxSXzKd8ig4nyLerNKvq0n847ewCx/ufh3ORuUsPh/rJT9VkKWw== 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: List-Subscribe: List-Unsubscribe: Hi Wei, On Mon, Mar 10, 2025 at 09:51:24AM +0000, Wei Yang wrote: > On Sun, Feb 23, 2025 at 12:22:29AM +0000, Wei Yang wrote: > >On Wed, Feb 19, 2025 at 09:24:31AM +0200, Mike Rapoport wrote: > >>Hi, > >> > >>On Tue, Feb 18, 2025 at 03:50:04PM +0000, Wei Yang wrote: > >>> On Thu, Feb 06, 2025 at 03:27:42PM +0200, Mike Rapoport wrote: > >>> >From: "Mike Rapoport (Microsoft)" > >>> > > >>> >to denote areas that were reserved for kernel use either directly with > >>> >memblock_reserve_kern() or via memblock allocations. > >>> > > >>> >Signed-off-by: Mike Rapoport (Microsoft) > >>> >--- > >>> > include/linux/memblock.h | 16 +++++++++++++++- > >>> > mm/memblock.c | 32 ++++++++++++++++++++++++-------- > >>> > 2 files changed, 39 insertions(+), 9 deletions(-) > >>> > > >>> >diff --git a/include/linux/memblock.h b/include/linux/memblock.h > >>> >index e79eb6ac516f..65e274550f5d 100644 > >>> >--- a/include/linux/memblock.h > >>> >+++ b/include/linux/memblock.h > >>> >@@ -50,6 +50,7 @@ enum memblock_flags { > >>> > MEMBLOCK_NOMAP = 0x4, /* don't add to kernel direct mapping */ > >>> > MEMBLOCK_DRIVER_MANAGED = 0x8, /* always detected via a driver */ > >>> > MEMBLOCK_RSRV_NOINIT = 0x10, /* don't initialize struct pages */ > >>> >+ MEMBLOCK_RSRV_KERN = 0x20, /* memory reserved for kernel use */ > >>> > >>> Above memblock_flags, there are comments on explaining those flags. > >>> > >>> Seems we miss it for MEMBLOCK_RSRV_KERN. > >> > >>Right, thanks! > >> > >>> > > >>> > #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP > >>> >@@ -1459,14 +1460,14 @@ phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size, > >>> > again: > >>> > found = memblock_find_in_range_node(size, align, start, end, nid, > >>> > flags); > >>> >- if (found && !memblock_reserve(found, size)) > >>> >+ if (found && !__memblock_reserve(found, size, nid, MEMBLOCK_RSRV_KERN)) > >>> > >>> Maybe we could use memblock_reserve_kern() directly. If my understanding is > >>> correct, the reserved region's nid is not used. > >> > >>We use nid of reserved regions in reserve_bootmem_region() (commit > >>61167ad5fecd ("mm: pass nid to reserve_bootmem_region()")) but KHO needs to > >>know the distribution of reserved memory among the nodes before > >>memmap_init_reserved_pages(). > >> > > > >I took another look into this commit. There maybe a very corner case in which > >will leave a reserved region with no nid set. > > > >memmap_init_reserved_pages() > > for_each_mem_region() { > > ... > > memblock_set_node(start, end, &memblock.reserved, nid); > > } > > > >We leverage the iteration here to set nid to all regions in memblock.reserved. > >But memblock_set_node() may call memblock_double_array() to expand the array, > >which may get a range before current start. So we would miss to set the > >correct nid to the new reserved region. > > > >I have tried to create a case in memblock test. This would happen when there > >are 126 memblock.reserved regions. And the last region is across the last two > >node. > > > >One way to fix this is compare type->max in memblock_set_node(). Then check > >this return value in memmap_init_reserved_pages(). If we found the size > >changes, repeat the iteration. > > > >But this is a very trivial one, not sure it worth fix. > > > > Hi, Mike > > I have done a user space test which shows we may have a chance to leave a > region with non-nid set. > > Not sure you are ok with my approach of fixing. Wouldn't it be better to check for a change in reserved.max in memmap_init_reserved_pages()? > -- > Wei Yang > Help you, Help me -- Sincerely yours, Mike.