From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756364Ab3KHEWe (ORCPT ); Thu, 7 Nov 2013 23:22:34 -0500 Received: from mail7.hitachi.co.jp ([133.145.228.42]:53402 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754244Ab3KHEWb (ORCPT ); Thu, 7 Nov 2013 23:22:31 -0500 X-AuditID: 85900ec0-d452db9000001514-f1-527c6705810e Subject: [PATCH -tip 0/2] ftrace: Introduce the new I/F "nr_saved_cmdlines" To: linux-kernel@vger.kernel.org From: Yoshihiro YUNOMAE Cc: Frederic Weisbecker , Ingo Molnar , Steven Rostedt Date: Fri, 08 Nov 2013 13:26:52 +0900 Message-ID: <20131108042652.26950.32013.stgit@yunodevel> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, This patch set introduces the new I/F "nr_saved_cmdlines" for increasing the number of saved cmdlines. Current saved_cmdlines can store just 128 command names and PIDs, but process names are often lost like <...> when we read trace data. If the process exists, we can get the name by using ps command. However, if the process already has not existed, we cannot get the name. To solve this issue, we introduce the new I/F "nr_saved_cmdlines" to expand the max number of saved command line names. This I/F is very simple. If we write a number to nr_saved_cmdlines, the number of command name will be stored. And, if we read the I/F, we can get current maximum number of command name. The default number is 128 which is current default number, so this patch does not change the usage of memory for saved_cmdlines when we boot kernel. Thanks! --- Yoshihiro YUNOMAE (2): ftrace: Make saved_cmdlines use seq_read ftrace: Introduce nr_saved_cmdlines I/F kernel/trace/trace.c | 296 +++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 241 insertions(+), 55 deletions(-) -- Yoshihiro YUNOMAE Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: yoshihiro.yunomae.ez@hitachi.com