Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751744AbaBFOHV (ORCPT ); Thu, 6 Feb 2014 09:07:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33657 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751572AbaBFOHR (ORCPT ); Thu, 6 Feb 2014 09:07:17 -0500 Date: Thu, 6 Feb 2014 12:07:05 -0200 From: Arnaldo Carvalho de Melo To: Stephane Eranian Cc: LKML , Peter Zijlstra , "mingo@elte.hu" , Jiri Olsa , Eric Dumazet Subject: Re: [BUG] perf top: --stdio causes continuous refresh Message-ID: <20140206140705.GB26955@infradead.org> References: <20140206135627.GA26955@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Thu, Feb 06, 2014 at 02:58:01PM +0100, Stephane Eranian escreveu: > On Thu, Feb 6, 2014 at 2:56 PM, Arnaldo Carvalho de Melo > wrote: > > Em Wed, Feb 05, 2014 at 10:25:09PM +0100, Stephane Eranian escreveu: > >> If you run perf top on 3.14 but you force --stdio mode, perf top > >> goes crazy and constantly refreshes the output. > >> It does that with many older versions of the perf as well on 3.14. > >> It runs fine with newt mode. > >> Works fine with my 3.11 kernel. So something must be broken > >> with 3.14. > >> Can you reproduce the problem as well? > > Not so far, using my perf/urgent branch: > I am using tip.git. Or try 3.11, 3.10. Tried torvalds/master, no problem, looking at what the top's screen refresh thread does we can see: [root@ssdandy ~]# trace -t 3562 -e \!write 0.000 ( 0.000 ms): ... [continued]: poll()) = 0 Timeout 2031.522 (2002.480 ms): poll(ufds: 0x7fbb91596bb0, nfds: 1, timeout_msecs: 2000 ) = 0 Timeout 4064.346 (2002.456 ms): poll(ufds: 0x7fbb91596bb0, nfds: 1, timeout_msecs: 2000 ) = 0 Timeout ^C[root@ssdandy ~]# I.e. waiting the default of: .delay_secs = 2, 2 seconds between refreshes. Checking out tip.tip, or are you suggesting to try an old perf binary, from 3.11 or 3.10 on top of a newer kernel? - Arnaldo -- 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/