From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761694Ab2COLo3 (ORCPT ); Thu, 15 Mar 2012 07:44:29 -0400 Received: from www.linutronix.de ([62.245.132.108]:39735 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752685Ab2COLoY (ORCPT ); Thu, 15 Mar 2012 07:44:24 -0400 Message-Id: <20120314170736.617746873@linutronix.de> User-Agent: quilt/0.48-1 Date: Thu, 15 Mar 2012 11:44:22 -0000 From: Thomas Gleixner To: LKML Cc: Al Viro , Linus Torvalds , Ingo Molnar , Peter Zijlstra , Nick Piggin Subject: [patch 0/5] seqlock consolidation X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series consists of two parts: 1) Consolidate seqlocks and seqcount instead of having two implementations for the counter functionality 2) Extend seqlocks API and convert the open coded seqlocks in fs_struct and dentry to that. The main motivation of this change is to get rid of open coded seqlocks as they are difficult to handle in the real time patch, because the retry loops can cause live locks there, when the writer side gets preempted. RT needs to take the lock so the writer gets boosted and out of the way. With open coded seqlocks consisting of a spinlock and a seqcount we have no idea which lock to acquire. Aside of that replacing open coded constructs with proper functions is a worthwhile cleanup by itself. Thanks, tglx