Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751525AbaJSJXc (ORCPT ); Sun, 19 Oct 2014 05:23:32 -0400 Received: from mail-wg0-f45.google.com ([74.125.82.45]:48855 "EHLO mail-wg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751063AbaJSJXa (ORCPT ); Sun, 19 Oct 2014 05:23:30 -0400 Date: Sun, 19 Oct 2014 11:23:25 +0200 From: Ingo Molnar To: Daniel J Blueman Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Bjorn Helgaas , x86@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Steffen Persvold Subject: Re: [PATCH v2 5/5] Numachip: use 2GB memory block size Message-ID: <20141019092324.GA10027@gmail.com> References: <1413683152-31302-1-git-send-email-daniel@numascale.com> <1413683152-31302-5-git-send-email-daniel@numascale.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413683152-31302-5-git-send-email-daniel@numascale.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Daniel J Blueman wrote: > Use appropriate memory block size to reduce sysfs entry creation time > by 16x. > > Boot-tested with the four permutations of X86_UV and X86_NUMACHIP. > > Signed-off-by: Daniel J Blueman > --- > arch/x86/mm/init_64.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 5621c47..22ea6de 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -53,6 +53,7 @@ > #include > #include > #include > +#include > #include > > #include "mm_internal.h" > @@ -1235,9 +1236,9 @@ 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"); > +#ifdef CONFIG_X86_64 > + if (is_uv_system() || is_numachip_system()) { > + pr_info("Memory block size 2GB for large-SMP system\n"); > return 2UL * 1024 * 1024 * 1024; It would be a lot cleaner and more robust to have a more intelligent decision here. Is there a reliable indicator for large 'sysfs entry creation time', such as a lot of RAM present? Also, it would be nice to list the pros/cons of this change, an advantage is reduced overhead - what are the disadvantages? Thanks, Ingo -- 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/