From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp08.in.ibm.com (e28smtp08.in.ibm.com [122.248.162.8]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp08.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 49DF62C02CB for ; Mon, 18 Feb 2013 21:28:49 +1100 (EST) Received: from /spool/local by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 18 Feb 2013 15:55:27 +0530 Received: from d28relay01.in.ibm.com (d28relay01.in.ibm.com [9.184.220.58]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 644E7E0058 for ; Mon, 18 Feb 2013 15:59:31 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r1IASVCd31457352 for ; Mon, 18 Feb 2013 15:58:31 +0530 Received: from d28av02.in.ibm.com (loopback [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r1IASYMR000961 for ; Mon, 18 Feb 2013 21:28:35 +1100 From: "Aneesh Kumar K.V" To: benh@kernel.crashing.org, paulus@samba.org Subject: [RFC PATCH 00/17] THP support for PPC64 Date: Mon, 18 Feb 2013 15:57:58 +0530 Message-Id: <1361183295-6958-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, This is an early RFC version adding transparent huge page support for PPC64. I am sharing the changes, so that we can have early review on the approach taken. The TODOs include *) Compile issues with different config option *) HugeTLBfs is disabled now (mostly compile issues) *) PPC32 and other sub architecture details need to be worked out. *) 4K page size details need to be worked out *) Closer review of PMD* flags. Some numbers: The latency measurements code from Anton found at http://ozlabs.org/~anton/junkcode/latency2001.c THP disabled 64K page size ------------------------ [root@llmp24l02 ~]# ./latency2001 8G 8589934592 731.73 cycles 205.77 ns [root@llmp24l02 ~]# ./latency2001 8G 8589934592 743.39 cycles 209.05 ns [root@llmp24l02 ~]# THP disabled large page via hugetlbfs ------------------------------------- [root@llmp24l02 ~]# ./latency2001 -l 8G 8589934592 416.09 cycles 117.01 ns [root@llmp24l02 ~]# ./latency2001 -l 8G 8589934592 415.74 cycles 116.91 ns THP enabled 64K page size. ---------------- [root@llmp24l02 ~]# ./latency2001 8G 8589934592 405.07 cycles 113.91 ns [root@llmp24l02 ~]# ./latency2001 8G 8589934592 411.82 cycles 115.81 ns [root@llmp24l02 ~]# We are close to hugetlbfs in latency and we can achieve this with zero config/page reservation. Most of the allocations above are fault allocated. I haven't really measured the collapse alloc impact. Another test that does 50000000 random access over 1GB area goes from 2.65 seconds to 1.07 seconds with this patchset. Thanks, -aneesh