From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751419AbdGQURP (ORCPT ); Mon, 17 Jul 2017 16:17:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:48680 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751320AbdGQURO (ORCPT ); Mon, 17 Jul 2017 16:17:14 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0794122BCC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Date: Mon, 17 Jul 2017 16:17:12 -0400 From: Steven Rostedt To: Will Hawkins Cc: linux-kernel@vger.kernel.org Subject: Re: Help with trace-cmd/ftrace recording process ID information Message-ID: <20170717161712.6bc38c83@gandalf.local.home> In-Reply-To: References: <20170717155352.2c94e662@gandalf.local.home> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 17 Jul 2017 16:06:37 -0400 Will Hawkins wrote: > This seems to be the problem: > > On the "good" system, that file is up-to-date with cached PIDs and > comms. On the bad host, there are no cached entries from any of the > traces that I've run. > > Because these are running old kernels, there is no saved_cmdlines_size > knob to turn. Do you have any idea why the saved_cmdlines would not be > getting updated appropriately on the "bad" host? I know this is not > ideal, but I can try to reboot that host and see if something is Yeah, a reboot may work. > simply wedged. The system has been online for almost a year, so it's > possible that something has gone wrong. > > Any help you can offer would be great! Thank you, again, for your response! The recording of command lines only happens when tracing is done, and there were a few bugs with the older kernels that caused it to either stop and never start again, or to simply just miss a bunch of recording. It may be that it stopped and never started again, so you will only have a stale file. -- Steve