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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9003C00144 for ; Wed, 27 Jul 2022 00:14:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240032AbiG0AOX (ORCPT ); Tue, 26 Jul 2022 20:14:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233303AbiG0AOX (ORCPT ); Tue, 26 Jul 2022 20:14:23 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2C023AB11; Tue, 26 Jul 2022 17:14:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id AB056B818CC; Wed, 27 Jul 2022 00:14:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A698C433D6; Wed, 27 Jul 2022 00:14:18 +0000 (UTC) Date: Tue, 26 Jul 2022 20:14:12 -0400 From: Steven Rostedt To: Beau Belgrave Cc: mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH v2 6/7] tracing/user_events: Use bits vs bytes for enabled status page data Message-ID: <20220726201412.7fbd3b1f@rorschach.local.home> In-Reply-To: <20220727000249.GA2289@kbox> References: <20220425184631.2068-1-beaub@linux.microsoft.com> <20220425184631.2068-7-beaub@linux.microsoft.com> <20220726180115.69320865@gandalf.local.home> <20220727000249.GA2289@kbox> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Tue, 26 Jul 2022 17:02:49 -0700 Beau Belgrave wrote: > > > /* Limit how long of an event name plus args within the subsystem. */ > > > #define MAX_EVENT_DESC 512 > > > #define EVENT_NAME(user_event) ((user_event)->tracepoint.name) > > > #define MAX_FIELD_ARRAY_SIZE 1024 > > > > > > +#define STATUS_BYTE(bit) ((bit) >> 3) > > > +#define STATUS_MASK(bit) (1 << ((bit) & 7)) > > > + > > > +/* Internal bits to keep track of connected probes */ > > > +#define EVENT_STATUS_FTRACE (1 << 0) > > > +#define EVENT_STATUS_PERF (1 << 1) > > > +#define EVENT_STATUS_OTHER (1 << 7) > > > > Did you mean to shift STATUS_OTHER by 7? > > > > Yes, it should be the value 128. > > > Is EVENT_STATUS_OTHER suppose to be one of the flags within the 3 bits of > > the 7 in STATUS_MASK? > > > > My thought was that STATUS_OTHER would stay on the highest bit. > Then when we have other systems they would slot into (1 << 2), etc. > > This may not be as important now since the byte is never given back to > the user and is only used when printing out status via the > user_events_status file in text form. So, it is confusing because of STATUS_MASK() is bits 0,1,2 and we are only using bits 0 and 1, with a OTHER bit at bit 7. And it would be good to use the BIT() macro. Is STATUS_OTHER suppose to be part of STATUS_MASK()? -- Steve