From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750734AbVHMA2o (ORCPT ); Fri, 12 Aug 2005 20:28:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750744AbVHMA2o (ORCPT ); Fri, 12 Aug 2005 20:28:44 -0400 Received: from zproxy.gmail.com ([64.233.162.203]:54168 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S1750734AbVHMA2o convert rfc822-to-8bit (ORCPT ); Fri, 12 Aug 2005 20:28:44 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=QUO2mSM9V8uM+huUqf427v5LCHudy+GUgH55+w/mQQxFMxh4E7/mLEQ6MMTC0llUJ+0R9FdEB8PQQYQul9P1wKEHz1i1j+i0ffwInuP0KU2l03H0WT2AI/zfx6cW0r3sDJ1vY3pyL3jjxvB+s78igDMIStwZugP9VMIO8HVWBhg= Message-ID: <1c1c8636050812172817b14384@mail.gmail.com> Date: Sat, 13 Aug 2005 12:28:43 +1200 From: Ryan Brown To: Ingo Molnar Subject: Re: [patch] Real-Time Preemption, -RT-2.6.13-rc4-V0.7.53-01, High Resolution Timers & RCU-tasklist features Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , "Paul E. McKenney" , george anzinger In-Reply-To: <20050811110051.GA20872@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <20050811110051.GA20872@elte.hu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org is there a patch available for -rc6? On 8/11/05, Ingo Molnar wrote: > > i have released the -53-01 Real-Time Preemption patch, which can be > downloaded from: > > http://redhat.com/~mingo/realtime-preempt/ > > there are two new features in this release, which justified the jump > from .52 to .53: > > - the inclusion of the High Resolution Timers patch, written by > George Anzinger, and ported/improved/cleaned-up by Thomas Gleixner. > > - the inclusion of the RCU tasklist_lock patch from Paul McKenney. > > the HRT patch from George Anzinger is a crutial piece of real-time > infrastructure. The version included in the -RT tree supports both PIT > and local APIC timer driven variable-rate timer interrupts. > > Thomas Glexiner, besides porting it to PREEMPT_RT, cleaning it up, > adding the local APIC timer support has also added the > CONFIG_HIGH_RES_TIMERS_DYN_PRIO feature, which pushes priority > inheritance into the high-res timer space. Furthermore, Thomas has > extended nanosleep to use HR timers, if the task is RT. This makes it > easier to test HRT functionality. > > NOTE: there's a new softirq, softirq-hrtimer (PID 8 on UP x86), which > should be chrt-ed to higher than SCHED_FIFO-50 if HR timer interrupts > are the most important latencies in the system. E.g.: > > chrt -f 90 -p 8 > > the RCU tasklist-lock patch is a small but important feature from Paul > McKenney which enables good HRT latencies: the HRT patch, when using > POSIX timers, would use a signal-sending codepath that depends on the > tasklist_lock, and thus the (quite high) tasklist_lock latencies > controlled the latency of HR timers - defeating much of the benefits of > HR timers. With the RCU tasklist-lock the signal sending path is now > RCU-read locked, with no locking dependency, and thus excellent > worst-case latencies. > > given these changes, some (mostly build-related) regressions are to be > expected. Only the x86 architecture is expected to work for now. > > to build a -V0.7.53-01 tree, the following patches should to be applied: > > http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.12.tar.bz2 > http://kernel.org/pub/linux/kernel/v2.6/testing/patch-2.6.13-rc4.bz2 > http://redhat.com/~mingo/realtime-preempt/realtime-preempt-2.6.13-rc4-RT-V0.7.53-01 > > patches, bugreports and any other feedback welcome, > > Ingo > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >