From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752001AbaAOBKa (ORCPT ); Tue, 14 Jan 2014 20:10:30 -0500 Received: from lgeamrelo02.lge.com ([156.147.1.126]:58308 "EHLO LGEAMRELO02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751908AbaAOBK1 (ORCPT ); Tue, 14 Jan 2014 20:10:27 -0500 X-AuditID: 9c93017e-b7b63ae000000e6a-d7-52d5e00070dc From: Minchan Kim To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Nitin Gupta , Sergey Senozhatsky , Jerome Marchand , Minchan Kim Subject: [PATCH v2 0/4]zram: locking redesign Date: Wed, 15 Jan 2014 10:11:06 +0900 Message-Id: <1389748270-15618-1-git-send-email-minchan@kernel.org> X-Mailer: git-send-email 1.8.5.2 X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, zram->lock rw_semaphore is coarse-grained so it hurts for scalability. This patch try to enhance it with remove the lock in read path. [1] uses atomic opeartion so it removes dependency of 32bit stat from zram->lock. [2] introduces table own lock instead of relying on zram->lock. [3] remove free pending slot mess so it makes core very clean. [4] finally removes zram->lock in read path and changes it with mutex. So, output is wonderful. read/write mixed workload performs well 11 times than old and write concurrency is also enhanced because mutex supports SPIN_ON_OWNER while rw_semaphore doesn't yet. (I know recenty there were some effort to enhance it for rw_semaphore from Tim Chen but not sure it got merged. Anyway, we don't need it any more and there is no reason to prevent read-write concurrency) Thanks. Minchan Kim (4): [1] zram: use atomic operation for stat [2] zram: introduce zram->tb_lock [3] zram: remove workqueue for freeing removed pending slot [4] zram: Remove zram->lock in read path and change it with mutex drivers/staging/zram/zram_drv.c | 117 ++++++++++++++++------------------------ drivers/staging/zram/zram_drv.h | 27 +++------- 2 files changed, 51 insertions(+), 93 deletions(-) -- 1.8.5.2