Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753313AbaKDRWv (ORCPT ); Tue, 4 Nov 2014 12:22:51 -0500 Received: from terminus.zytor.com ([198.137.202.10]:60086 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751502AbaKDRWr (ORCPT ); Tue, 4 Nov 2014 12:22:47 -0500 Date: Tue, 4 Nov 2014 09:22:29 -0800 From: tip-bot for Daniel J Blueman Message-ID: Cc: sp@numascale.com, tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org, bhelgaas@google.com, daniel@numascale.com, mingo@kernel.org Reply-To: sp@numascale.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, hpa@zytor.com, daniel@numascale.com, mingo@kernel.org, bhelgaas@google.com In-Reply-To: <1415089784-28779-4-git-send-email-daniel@numascale.com> References: <1415089784-28779-4-git-send-email-daniel@numascale.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86: mm: Use 2GB memory block size on large-memory x86-64 systems Git-Commit-ID: bdee237c0343a5d1a6cf72c7ea68e88338b26e08 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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)) -- 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/