Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752080AbaKEWKw (ORCPT ); Wed, 5 Nov 2014 17:10:52 -0500 Received: from mail-ig0-f175.google.com ([209.85.213.175]:40993 "EHLO mail-ig0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751926AbaKEWKt (ORCPT ); Wed, 5 Nov 2014 17:10:49 -0500 MIME-Version: 1.0 In-Reply-To: References: <1415089784-28779-4-git-send-email-daniel@numascale.com> Date: Wed, 5 Nov 2014 14:10:48 -0800 X-Google-Sender-Auth: xacAdu05oYX2hltykq0ikWpqxPc Message-ID: Subject: Re: [tip:x86/mm] x86: mm: Use 2GB memory block size on large-memory x86-64 systems From: Yinghai Lu To: Steffen Persvold , Linux Kernel Mailing List , "H. Peter Anvin" , Daniel J Blueman , Ingo Molnar , Bjorn Helgaas Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 4, 2014 at 9:22 AM, tip-bot for Daniel J Blueman wrote: > Commit-ID: bdee237c0343a5d1a6cf72c7ea68e88338b26e08 > Gitweb: http://git.kernel.org/tip/bdee237c0343a5d1a6cf72c7ea68e88338b26e08 > Author: Daniel J Blueman > AuthorDate: Tue, 4 Nov 2014 16:29:44 +0800 > Committer: Thomas Gleixner > CommitDate: Tue, 4 Nov 2014 18:19:27 +0100 > > x86: mm: Use 2GB memory block size on large-memory x86-64 systems > > On large-memory x86-64 systems of 64GB or more with memory hot-plug > enabled, use a 2GB memory block size. Eg with 64GB memory, this reduces > the number of directories in /sys/devices/system/memory from 512 to 32, > making it more manageable, and reducing the creation time accordingly. > > This caveat is that the memory can't be offlined (for hotplug or > otherwise) with the finer default 128MB granularity, but this is > unimportant due to the high memory densities generally used with such > large-memory systems, where eg a single DIMM is the order of 16GB. > > Signed-off-by: Daniel J Blueman > Cc: Steffen Persvold > Cc: Bjorn Helgaas > Link: http://lkml.kernel.org/r/1415089784-28779-4-git-send-email-daniel@numascale.com > Signed-off-by: Thomas Gleixner > --- > arch/x86/mm/init_64.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 4cb8763..ebca30f 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -52,7 +52,6 @@ > #include > #include > #include > -#include > #include > > #include "mm_internal.h" > @@ -1247,12 +1246,10 @@ static unsigned long probe_memory_block_size(void) > /* start from 2g */ > unsigned long bz = 1UL<<31; > > -#ifdef CONFIG_X86_UV > - if (is_uv_system()) { > - printk(KERN_INFO "UV: memory block size 2GB\n"); > + if (totalram_pages >= (64ULL << (30 - PAGE_SHIFT))) { > + pr_info("Using 2GB memory block size for large-memory system\n"); > return 2UL * 1024 * 1024 * 1024; > } > -#endif > > /* less than 64g installed */ > if ((max_pfn << PAGE_SHIFT) < (16UL << 32)) ..... Come on. Can you remove the following dead lines caused by this patch the same time ? Yinghai -- 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/