Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751586AbaJZQqI (ORCPT ); Sun, 26 Oct 2014 12:46:08 -0400 Received: from mail-pd0-f170.google.com ([209.85.192.170]:54725 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751391AbaJZQqG (ORCPT ); Sun, 26 Oct 2014 12:46:06 -0400 Message-ID: <1414341964.5609.3.camel@edumazet-glaptop2.roam.corp.google.com> Subject: Re: vmalloced stacks on x86_64? From: Eric Dumazet To: "H. Peter Anvin" Cc: Andy Lutomirski , X86 ML , "linux-kernel@vger.kernel.org" , Linus Torvalds Date: Sun, 26 Oct 2014 09:46:04 -0700 In-Reply-To: <544B0D22.2070509@zytor.com> References: <544B0D22.2070509@zytor.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2014-10-24 at 19:38 -0700, H. Peter Anvin wrote: > On 10/24/2014 05:22 PM, Andy Lutomirski wrote: > > Is there any good reason not to use vmalloc for x86_64 stacks? > > Additional TLB pressure if anything else. It seems TLB pressure gets less and less interest these days... Is it still worth trying to reduce it ? I was wondering for example why 'hashdist' is not cleared if current host runs a NUMA enabled kernel, but has a single node. Something like following maybe ? diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 7dbe5ec9d9cd08afac13797e2adac291fb703eec..0846ef054b0620a7be0c6f69b1a2f21c78d57d3b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1181,7 +1181,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. hashdist= [KNL,NUMA] Large hashes allocated during boot are distributed across NUMA nodes. Defaults on for 64-bit NUMA, off otherwise. - Format: 0 | 1 (for off | on) + Format: 0 | 1 | 2 (for off | on if NUMA host | on) hcl= [IA-64] SGI's Hardware Graph compatibility layer diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index 1a883705a12a8a12410914be93b2ee65807cc423..8aded4c11c8c1cc5778e9ae2b9cd5146070b5b03 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -668,7 +668,8 @@ static int __init dummy_numa_init(void) node_set(0, numa_nodes_parsed); numa_add_memblk(0, 0, PFN_PHYS(max_pfn)); - + if (hashdist == HASHDIST_DEFAULT) + hashdist = 0; return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/