From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel Subject: Re: 1us latency? Date: Mon, 3 Aug 2015 20:59:56 +0300 Message-ID: <55BFAC1C.9020508@pavlinux.ru> References: <55BF4CD7.8000007@pavlinux.ru> <20150803114422.0efbea1b@sluggy> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Linux RT Users To: Clark Williams Return-path: Received: from forward3m.cmail.yandex.net ([5.255.216.21]:45695 "EHLO forward3m.cmail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752711AbbHCSGn (ORCPT ); Mon, 3 Aug 2015 14:06:43 -0400 In-Reply-To: <20150803114422.0efbea1b@sluggy> Sender: linux-rt-users-owner@vger.kernel.org List-ID: 03.08.2015 19:44, Clark Williams =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > On Mon, 3 Aug 2015 14:13:27 +0300 > pavel wrote: > >> # ./cyclictest -S -p fifo >> defaulting realtime priority to 9 >> # /dev/cpu_dma_latency set to 0us >> policy: fifo: loadavg: 0.00 0.03 0.05 1/218 4240 >> >> T: 0 ( 4174) P: 9 I:1000 C: 430806 Min: 1 Act: 1 Avg: 1 M= ax: 10 >> T: 1 ( 4175) P: 9 I:1500 C: 287204 Min: 1 Act: 1 Avg: 1 M= ax: 6 >> T: 2 ( 4176) P: 9 I:2000 C: 215403 Min: 1 Act: 2 Avg: 1 M= ax: 11 >> T: 3 ( 4177) P: 9 I:2500 C: 172322 Min: 1 Act: 1 Avg: 1 M= ax: 9 >> T: 4 ( 4178) P: 9 I:3000 C: 143602 Min: 1 Act: 1 Avg: 1 M= ax: 10 >> T: 5 ( 4179) P: 9 I:3500 C: 123087 Min: 1 Act: 1 Avg: 1 M= ax: 11 >> T: 6 ( 4180) P: 9 I:4000 C: 107701 Min: 1 Act: 1 Avg: 1 M= ax: 10 >> T: 7 ( 4181) P: 9 I:4500 C: 108232 Min: 1 Act: 2 Avg: 1 M= ax: 11 >> >> >> It possible? 1us latency? o_O >> >> kernel- 3.18.19-rt15 >> cyclictest V 0.92 >> Intel(R) Xeon(R) CPU E3-1246 v3 @ 3.50GHz >> MSI MS-7823/B85M-G43 (MS-7823), BIOS V3.14B3 06/23/2014 >> -- > No, your latency is 11us. Max latency is what we care about, not the > average. By the way, max values appear only at the start, then they are roughly = equal to=20 the average. -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html