Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753827AbbK0ChA (ORCPT ); Thu, 26 Nov 2015 21:37:00 -0500 Received: from rs224.mailgun.us ([209.61.151.224]:52352 "EHLO rs224.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753710AbbK0Cg4 (ORCPT ); Thu, 26 Nov 2015 21:36:56 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=variantweb.net; s=smtp; q=dns; h=Sender: From: To: Cc: Subject: Date: Message-Id; b=Iz/1OIsPsO2+wfsxhzORug/4JmlpsZE/0uGahp4Oo+OaJ53ox8teX+uSL5BNMy9Bnj/Uma 9rDkX0dt3diRy1TQ31ISy/uZ/8ucv2qS1xq32/mYmZRafe8Ou6QA80tn7QtbF7ixOMb5CphR 1R8aoHag2ioOpeC1YjizLdhOAshO8= X-Mailgun-Sid: WyJmNDFlMyIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgIjlkYjc2Il0= From: Seth Jennings To: Thomas Gleixner Cc: Seth Jennings , Ingo Molnar , Peter Anvin , Daniel J Blueman , Yinghai Lu , x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCHv2] x86: mm: clean up probe_memory_block_size() Date: Thu, 26 Nov 2015 20:36:49 -0600 Message-Id: <1448591809-10369-1-git-send-email-sjennings@variantweb.net> X-Mailer: git-send-email 2.5.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2280 Lines: 73 v2: remove local bz variable (Ingo) and debug message since, if the 2GB message doesn't print, there is only one possible block size. The cumulative effect of bdee237c and 982792c7 is some pretty convoluted code. This commit has no (intended) functional change; just seeks to simplify and make the code more understandable. The whole section with the "tail size" doesn't seem to be reachable, since both the >= 64GB and < 64GB case return, so it was removed. This commit also adds code back for the UV case since it seemed to just go away without reason in bdee237c and might lead to unexpected change in behavior. Signed-off-by: Seth Jennings --- arch/x86/mm/init_64.c | 24 +++++------------------- 1 file changed, 5 insertions(+), 19 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index ec081fe..b05df4f 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -52,6 +52,7 @@ #include #include #include +#include #include #include "mm_internal.h" @@ -1194,28 +1195,13 @@ int kern_addr_valid(unsigned long addr) static unsigned long probe_memory_block_size(void) { - /* start from 2g */ - unsigned long bz = 1UL<<31; - - if (totalram_pages >= (64ULL << (30 - PAGE_SHIFT))) { + /* if system is UV or has 64GB of RAM or more, use large blocks */ + if (is_uv_system() || ((max_pfn << PAGE_SHIFT) >= (64UL << 30))) { pr_info("Using 2GB memory block size for large-memory system\n"); - return 2UL * 1024 * 1024 * 1024; + return 2UL << 30; /* 2GB */ } - /* less than 64g installed */ - if ((max_pfn << PAGE_SHIFT) < (16UL << 32)) - return MIN_MEMORY_BLOCK_SIZE; - - /* get the tail size */ - while (bz > MIN_MEMORY_BLOCK_SIZE) { - if (!((max_pfn << PAGE_SHIFT) & (bz - 1))) - break; - bz >>= 1; - } - - printk(KERN_DEBUG "memory block size : %ldMB\n", bz >> 20); - - return bz; + return MIN_MEMORY_BLOCK_SIZE; } static unsigned long memory_block_size_probed; -- 2.5.0 -- 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/