Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750800AbWEMXBm (ORCPT ); Sat, 13 May 2006 19:01:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751053AbWEMXBm (ORCPT ); Sat, 13 May 2006 19:01:42 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:44996 "EHLO e6.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1750800AbWEMXBl (ORCPT ); Sat, 13 May 2006 19:01:41 -0400 From: Darren Hart Organization: IBM Linux Technology Center To: Lee Revell Subject: Re: rt20 scheduling latency testcase and failure data Date: Sat, 13 May 2006 16:01:31 -0700 User-Agent: KMail/1.9.1 Cc: lkml , Ingo Molnar , Thomas Gleixner , Mike Galbraith , Steven Rostedt , Florian Schmidt References: <200605121924.53917.dvhltc@us.ibm.com> <200605131106.16864.dvhltc@us.ibm.com> <1147544472.6535.294.camel@mindpipe> In-Reply-To: <1147544472.6535.294.camel@mindpipe> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200605131601.31880.dvhltc@us.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2307 Lines: 87 On Saturday 13 May 2006 11:21, Lee Revell wrote: > On Sat, 2006-05-13 at 11:06 -0700, Darren Hart wrote: > > 1 [softirq-timer/0] > > What happens if you set the softirq-timer threads to 99? > After setting all 4 softirq-timer threads to prio 99 I seemed to get only 2 failures in 100 runs. #51 slept too long (10ms too long!), the latency appeared after the sleep in #90 (nearly 483ms worth). Those latencies seem huge to me. ITERATIONS 0-50 Passed ITERATION 51 ------------------------------- Scheduling Latency ------------------------------- Running 10000 iterations with a period of 5 ms Expected running time: 50 s ITERATION DELAY(US) MAX_DELAY(US) FAILURES --------- --------- ------------- -------- 7000 10197 10197 1 PERIOD MISSED! scheduled delta: 4079 us actual delta: 14263 us latency: 10183 us --------------------------------------- previous start: 35010197 us now: 35011117 us scheduled start: 35005000 us next scheduled start is in the past! Start Latency: 114 us: FAIL Min Latency: 9 us: PASS Avg Latency: 7 us: PASS Max Latency: 10197 us: FAIL Failed Iterations: 1 ITERATIONS 52-89 Passed ITERATION 90 ------------------------------- Scheduling Latency ------------------------------- Running 10000 iterations with a period of 5 ms Expected running time: 50 s ITERATION DELAY(US) MAX_DELAY(US) FAILURES --------- --------- ------------- -------- 2747 9 20 0 PERIOD MISSED! scheduled delta: 4072 us actual delta: 4079 us latency: 6 us --------------------------------------- previous start: 13735009 us now: 14218183 us scheduled start: 13740000 us next scheduled start is in the past! Start Latency: 112 us: FAIL Min Latency: 8 us: PASS Avg Latency: 2 us: PASS Max Latency: 20 us: PASS Failed Iterations: 0 ITERATIONS 91-99 Passed Thanks, -- Darren Hart IBM Linux Technology Center Realtime Linux Team - 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/