From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D066C433EF for ; Mon, 6 Sep 2021 08:13:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FA9261027 for ; Mon, 6 Sep 2021 08:13:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240660AbhIFIOw (ORCPT ); Mon, 6 Sep 2021 04:14:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239780AbhIFIOv (ORCPT ); Mon, 6 Sep 2021 04:14:51 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59876C061575 for ; Mon, 6 Sep 2021 01:13:47 -0700 (PDT) Date: Mon, 6 Sep 2021 10:13:43 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1630916024; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vYHBl87y3v8Ieky0bj4T/DhMiiK93Kxq3slzmlTSg2A=; b=o9/UDVQ+51nWr44c6wetNcWoBuHo6IwP+/bkKa5WT3Z9dP+lG0QspuRogF/HF6Z+EOlOFS eQMUsEmmxlUCuhGdx+Y7OfODDse+zx+CvYIWBwJWlOcFVccjjJw6zvftYSbZryW/t6x7Z1 PlgUsvlvHsl/XqJBVfP0BEdOpoI9sdKvG3OOK2e1QXEvNJz9jk9OFko0wit64nXtZ1u0LD AQhQi9AVC1FBtl9Zsqik/UbNxf2ry88/og4qgXzMUpSHSEYfOwh7zO/gmWmxMdXFPwzLLf 3lH7PKtwtTEahMAYGTu4h1D+u9axlsb9jalXG8hW5ck+Q7LwlsQpu5bs89oqBQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1630916024; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vYHBl87y3v8Ieky0bj4T/DhMiiK93Kxq3slzmlTSg2A=; b=RwVcuBBDgG2GYWaiy0dYXBXyDSkTkJyILPdBve27jb5ltsyhQo71HF/MH08Y4Scu5X7HI2 hoNs3TMbc59J0dAw== From: Sebastian Andrzej Siewior To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Thomas Gleixner , Peter Zijlstra Subject: Re: [PATCH v2] trace: Add migrate-disabled counter to tracing output. Message-ID: <20210906081343.klxtb652s5aphg4z@linutronix.de> References: <20210806164907.xtgvrb25eb4isxhd@linutronix.de> <20210806135124.1279fc94@oasis.local.home> <20210810132625.ylssabmsrkygokuv@linutronix.de> <20210903194216.1392b62e@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210903194216.1392b62e@gandalf.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-09-03 19:42:16 [-0400], Steven Rostedt wrote: Hi Steven, > BTW, > > When doing a v2, always create a new thread. Never send it as a reply to > the previous patch. The reason I missed this is because replies to previous > patches do not end up in my internal patchwork. And I only look at that for > patches. Not my INBOX. oki. > > > --- a/kernel/trace/trace_events.c > > +++ b/kernel/trace/trace_events.c > > @@ -181,7 +181,8 @@ static int trace_define_common_fields(void) > > > > __common_field(unsigned short, type); > > __common_field(unsigned char, flags); > > - __common_field(unsigned char, preempt_count); > > + /* XXX */ > > + __common_field(unsigned char, preempt_mg_count); > > __common_field(int, pid); > > > > return ret; > > I'm going to have to nuke this hunk of the patch, and update all the other > locations that have preempt_mg_count in it. Because I just tested it, and > this breaks user space. I left that with that XXX on purpose so you can look and comment and say how to fix it. The problem I had with preempt_count was that only the lower nibble contains the preemption counter. So I thought you could easily came up with something how this can be split or taught to only expose the lower nibble. I didn't after a few attempts. My understanding is that this `preempt_count' is also used in the filter tracefs file so something like "preempt_count > 1" > filter would also match for migrate_count = 2, preempt_count = 1. You seem to be happy to filter in user space. Sebastian