From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 95077145A19; Fri, 19 Jul 2024 16:28:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721406537; cv=none; b=U+i9bXFZk+qPCd3Iz2s0pIOE0VyhNvqXLR/07nNP/sFoGw4ZPNDEqqhRtZEHGDEcbHadRVEMfi47ORmj668dSgGMewRHa6VEn3lYlRU/Ce8iaq2itIKF4ORRf8pjAg+e65+M5JQrV/kSDCsT6pPmlcjKRK81PqCkYi86SCFV7+g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721406537; c=relaxed/simple; bh=N1pdKNBGQDY1wRXXdSL7Pu0XSWIwV9tnznh+gOEKyG8=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=uPcq5XOae/QSfvQsausuJ3JlZKal0ZA+thVyxIBBr/gzS4M7nN+GfpfBikIDhhplyT0KxK3pPv4le7DmsyGzcA/Sht90K0/pTw80TYAOYZc7baeRnS8TGWVejWuVNcLi/4iFPjE0uUaIgKKByBnIOctlmO7Ds624OVoOmW7f8QI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4WQZn61R1mz6K7Fc; Sat, 20 Jul 2024 00:26:34 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 9E616140517; Sat, 20 Jul 2024 00:28:51 +0800 (CST) Received: from localhost (10.48.157.16) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Fri, 19 Jul 2024 17:28:50 +0100 Date: Fri, 19 Jul 2024 17:28:49 +0100 From: Jonathan Cameron To: Mike Rapoport CC: , Alexander Gordeev , Andreas Larsson , "Andrew Morton" , Arnd Bergmann , "Borislav Petkov" , Catalin Marinas , Christophe Leroy , Dan Williams , Dave Hansen , David Hildenbrand , "David S. Miller" , Greg Kroah-Hartman , Heiko Carstens , Huacai Chen , Ingo Molnar , Jiaxun Yang , "John Paul Adrian Glaubitz" , Michael Ellerman , Palmer Dabbelt , "Rafael J. Wysocki" , Rob Herring , "Thomas Bogendoerfer" , Thomas Gleixner , Vasily Gorbik , Will Deacon , , , , , , , , , , , , , , , Subject: Re: [PATCH 06/17] x86/numa: simplify numa_distance allocation Message-ID: <20240719172849.000019a0@Huawei.com> In-Reply-To: <20240716111346.3676969-7-rppt@kernel.org> References: <20240716111346.3676969-1-rppt@kernel.org> <20240716111346.3676969-7-rppt@kernel.org> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-sh@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500006.china.huawei.com (7.191.161.198) To lhrpeml500005.china.huawei.com (7.191.163.240) On Tue, 16 Jul 2024 14:13:35 +0300 Mike Rapoport wrote: > From: "Mike Rapoport (Microsoft)" > > Allocation of numa_distance uses memblock_phys_alloc_range() to limit > allocation to be below the last mapped page. > > But NUMA initializaition runs after the direct map is populated and initialization (one too many 'i's) > there is also code in setup_arch() that adjusts memblock limit to > reflect how much memory is already mapped in the direct map. > > Simplify the allocation of numa_distance and use plain memblock_alloc(). > This makes the code clearer and ensures that when numa_distance is not > allocated it is always NULL. Doesn't this break the comment in numa_set_distance() kernel-doc? " * If such table cannot be allocated, a warning is printed and further * calls are ignored until the distance table is reset with * numa_reset_distance(). " Superficially that looks to be to avoid repeatedly hitting the singleton bit at the top of numa_set_distance() as SRAT or similar parsing occurs. > > Signed-off-by: Mike Rapoport (Microsoft) > --- > arch/x86/mm/numa.c | 12 +++--------- > 1 file changed, 3 insertions(+), 9 deletions(-) > > diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c > index 5e1dde26674b..ab2d4ecef786 100644 > --- a/arch/x86/mm/numa.c > +++ b/arch/x86/mm/numa.c > @@ -319,8 +319,7 @@ void __init numa_reset_distance(void) > { > size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]); > > - /* numa_distance could be 1LU marking allocation failure, test cnt */ > - if (numa_distance_cnt) > + if (numa_distance) > memblock_free(numa_distance, size); > numa_distance_cnt = 0; > numa_distance = NULL; /* enable table creation */ > @@ -331,7 +330,6 @@ static int __init numa_alloc_distance(void) > nodemask_t nodes_parsed; > size_t size; > int i, j, cnt = 0; > - u64 phys; > > /* size the new table and allocate it */ > nodes_parsed = numa_nodes_parsed; > @@ -342,16 +340,12 @@ static int __init numa_alloc_distance(void) > cnt++; > size = cnt * cnt * sizeof(numa_distance[0]); > > - phys = memblock_phys_alloc_range(size, PAGE_SIZE, 0, > - PFN_PHYS(max_pfn_mapped)); > - if (!phys) { > + numa_distance = memblock_alloc(size, PAGE_SIZE); > + if (!numa_distance) { > pr_warn("Warning: can't allocate distance table!\n"); > - /* don't retry until explicitly reset */ > - numa_distance = (void *)1LU; > return -ENOMEM; > } > > - numa_distance = __va(phys); > numa_distance_cnt = cnt; > > /* fill with the default distances */