From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755547Ab3AaBA2 (ORCPT ); Wed, 30 Jan 2013 20:00:28 -0500 Received: from LGEMRELSE7Q.lge.com ([156.147.1.151]:55464 "EHLO LGEMRELSE7Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753759Ab3AaBAZ (ORCPT ); Wed, 30 Jan 2013 20:00:25 -0500 X-AuditID: 9c930197-b7ca4ae000006ba8-88-5109c226f80f From: Joonsoo Kim To: Russell King Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, js1304@gmail.com, Will Deacon , Nicolas Pitre , Catalin Marinas , Joonsoo Kim Subject: [PATCH v4 0/3] introduce static_vm for ARM-specific static mapped area Date: Thu, 31 Jan 2013 10:00:05 +0900 Message-Id: <1359594008-14688-1-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In current implementation, we used ARM-specific flag, that is, VM_ARM_STATIC_MAPPING, for distinguishing ARM specific static mapped area. The purpose of static mapped area is to re-use static mapped area when entire physical address range of the ioremap request can be covered by this area. This implementation causes needless overhead for some cases. For example, assume that there is only one static mapped area and vmlist has 300 areas. Every time we call ioremap, we check 300 areas for deciding whether it is matched or not. Moreover, even if there is no static mapped area and vmlist has 300 areas, every time we call ioremap, we check 300 areas in now. If we construct a extra list for static mapped area, we can eliminate above mentioned overhead. With a extra list, if there is one static mapped area, we just check only one area and proceed next operation quickly. In fact, it is not a critical problem, because ioremap is not frequently used. But reducing overhead is better idea. Another reason for doing this work is for removing vm_struct list management, entirely. For more information, look at the following link. http://lkml.org/lkml/2012/12/6/184 Changelog v3->v4: [2/3]: Changes from Nicolas' suggestion - embed static_vm code in ioremap.c - simplify struct static_vm - remove init_static_vm, instead, add_static_vm_early() init static_vm Use generic list for list management of static_vm Convert spin_lock to rw_lock Modify static_vm's flags bits [3/3]: Rework according to [2/3] change Rebased on v3.8-rc5 v2->v3: coverletter: refer a link related to this work [2/3]: drop @flags of find_static_vm_vaddr Rebased on v3.8-rc4 v1->v2: [2/3]: patch description is improved. Rebased on v3.7-rc7 Joonsoo Kim (3): ARM: vmregion: remove vmregion code entirely ARM: ioremap: introduce an infrastructure for static mapped area ARM: mm: use static_vm for managing static mapped areas arch/arm/mm/Makefile | 2 +- arch/arm/mm/ioremap.c | 147 +++++++++++++++++++++++----------- arch/arm/mm/mm.h | 28 ++++--- arch/arm/mm/mmu.c | 47 ++++++----- arch/arm/mm/vmregion.c | 205 ------------------------------------------------ arch/arm/mm/vmregion.h | 31 -------- 6 files changed, 147 insertions(+), 313 deletions(-) delete mode 100644 arch/arm/mm/vmregion.c delete mode 100644 arch/arm/mm/vmregion.h -- 1.7.9.5