From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50958 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726238AbeHWT4r (ORCPT ); Thu, 23 Aug 2018 15:56:47 -0400 From: Waiman Long Subject: [PATCH 0/2] xfs: Use wake_q for waking up log space waiters Date: Thu, 23 Aug 2018 12:26:08 -0400 Message-Id: <1535041570-24102-1-git-send-email-longman@redhat.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" , Ingo Molnar , Peter Zijlstra Cc: linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, Dave Chinner , Waiman Long While running the AIM7 microbenchmark, it was found that there was a severe spinlock contention problem in the current XFS log space reservation code. To alleviate the problem, the log space waiter waiting and waking functions are modified to use the wake_q for waking up waiters without holding the lock so as to reduce the lock hold time. The result was a 4X performance improvement in that microbenchmark which is worth persuing. Patch 1 is an enablement patch to make wake_q service available to kernel modules. Patch 2 changes the XFS log space reservation code to use wake_q for task wakeup. Waiman Long (2): sched/core: Export wake_q functions to kernel modules xfs: Use wake_q for waking up log space waiters fs/xfs/xfs_log.c | 48 ++++++++++++++++++++++++++++++++++---------- include/linux/sched/wake_q.h | 5 +++++ kernel/sched/core.c | 2 ++ 3 files changed, 44 insertions(+), 11 deletions(-) -- 1.8.3.1