From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B218B3D902F; Thu, 5 Mar 2026 18:05:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772733931; cv=none; b=QH4S1o9vDgClFRMBSD+Xknced0jim6meNrvdEVcjyelnKHx2EcdBnjC0Xpdv9Qee7sAtXK6naaw5MNviR6TxK9GMGd0Rsxp7RUpPUll8SkC030bXy6+3djYFikRWO1EBfYu22TQ5JpHNPuwzrIOwW8HmS/WHjjzGYAK/ldK7+SQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772733931; c=relaxed/simple; bh=vU8WC2E3y4JSKjjc/LacAPhWsX82SYdBzV94iFaOGQA=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=J04FnPLqzvnzt/KBbU7aohJ5ddXEFqVXa4r1SHHLb+6qPquUvut2Q0RbU9/OyfT/2LBE9wLHuIX7hXxDmChpMslvX/H+wX64MU1z1qRnM23MkzG/dVFclImkn5Yb/is1+2cwouFJ21/IEMf7xA7qDd3iWmEOGgsPhhjmAn+tY9U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 71FE6C124F; Thu, 5 Mar 2026 18:05:28 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf04.hostedemail.com (Postfix) with ESMTPA id 8DC0520027; Thu, 5 Mar 2026 18:05:25 +0000 (UTC) Date: Thu, 5 Mar 2026 13:06:04 -0500 From: Steven Rostedt To: Peter Zijlstra Cc: Dmitry Ilvokhin , Dennis Zhou , Tejun Heo , Christoph Lameter , Masami Hiramatsu , Mathieu Desnoyers , Ingo Molnar , Will Deacon , Boqun Feng , Waiman Long , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH RFC 3/3] locking: Wire up contended_release tracepoint Message-ID: <20260305130604.659cca36@gandalf.local.home> In-Reply-To: <20260305174223.GA1442992@noisy.programming.kicks-ass.net> References: <8298e098d3418cb446ef396f119edac58a3414e9.1772642407.git.d@ilvokhin.com> <20260305105924.7069eb23@gandalf.local.home> <20260305174223.GA1442992@noisy.programming.kicks-ass.net> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: 7e37yoxoqbfox1qt9hisz4ytcd6fx6fk X-Rspamd-Server: rspamout02 X-Rspamd-Queue-Id: 8DC0520027 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX18NdASASaDUUqrewaKrX7VQ1YHMm7kOZy4= X-HE-Tag: 1772733925-773976 X-HE-Meta: U2FsdGVkX18Cwu3Ie+Ud/EYZs/iZOO+gEKcsZJG5kc+m818AijzCNfTe15GqcbqPGu5UD5364uYz52fYMJsuYKSLuVZMWPUxjHJqTuXpjdqUpzOpgHs/C86AVdvo4JPtJZ8OVPP96+eGAUdAAuEuP3XTuWY8kLZfsaIeqUAJQoDBOJjigtMWDFuNTQr6KFNJdwWtXDCBEIk2yPzkqg/0AShIPEhsBJ4ry5eOCUClWeoRC0Orw1pS3fQA3oU7ihUUpk51cgBmHeIKw4U9PFk6KKWrdgiRwxVPnq+HHiPvjLfLPgH+tR9enQ0AyVzzyjQLyS7dE6UWok/Y7/CrwJRoRvmXZlqb/w4bRh4RZIjZuYl9Qu0jmiVUw+Z/sQk2bP2x On Thu, 5 Mar 2026 18:42:23 +0100 Peter Zijlstra wrote: > I still wish you would accept: > > if (trace_foo_enabled() && foo) > __do_trace_foo(); > > The compilers can't optimize the static branches and thus you'll get it > twice for no reason. > > I really wish they would just accept __pure, but alas. Makes sense, and that could probably be done. It shouldn't be too hard to do. If I find some time I could look at it, or perhaps someone lurking on this thread could possibly give it a try! (I may even Cc some people that want to learn this code). -- Steve