From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) (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 31A7A1DB551; Tue, 28 Apr 2026 18:51:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777402304; cv=none; b=abcZw2zfsLPtT//v7+kMEL9w8gj4y8B/D4Lb590qWl3ZQ7puaOf1M1rGvFSPRQHAmJRCQ5pM7wX6il2JC9knHIBcUMKismUD/q87dtv20gVO139QD93XeD5fIY7OahF2YD/2/6uFDSUO41B39LuhqSzwdhHOD7kNMGVe/IkN0SE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777402304; c=relaxed/simple; bh=g6ikfoU1LHUCrwqZ6C3hHdK5O+DERhnchdkznqb6v1Q=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Pv2KmS1ootc9LL2Qvh4lGC856lLE3M4IyB0BQ5rHBwe6PoitabAsqKm+NpGloIVHT34SYf7Rj+85DSwX2caB0dEtdWa6UX2f5q5T8kZSUqYaMdu2zTm2kG8s6B4BaoIeI/nxQnENSZAY3PY1A7irTbrbQsvI6Kf9MA8yDH9KAOg= 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=216.40.44.16 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 omf07.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 51BF81C0619; Tue, 28 Apr 2026 18:51:40 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf07.hostedemail.com (Postfix) with ESMTPA id F3B2120030; Tue, 28 Apr 2026 18:51:36 +0000 (UTC) Date: Tue, 28 Apr 2026 14:51:51 -0400 From: Steven Rostedt To: Wander Lairson Costa Cc: Peter Zijlstra , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman , Valentin Schneider , Masami Hiramatsu , Mathieu Desnoyers , Andrew Morton , "open list:SCHEDULER" , "open list:TRACING" , acme@kernel.org, williams@redhat.com, gmonaco@redhat.com Subject: Re: [PATCH v3 1/4] tracing/preemptirq: Optimize preempt_disable/enable() tracepoint overhead Message-ID: <20260428145151.3860aa04@gandalf.local.home> In-Reply-To: References: <20260311125021.197638-1-wander@redhat.com> <20260311125021.197638-2-wander@redhat.com> <20260311193503.GS606826@noisy.programming.kicks-ass.net> <20260313090404.GK606826@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=UTF-8 Content-Transfer-Encoding: quoted-printable X-Stat-Signature: fezgicd8abfznjtxik31r639hekhshtq X-Rspamd-Server: rspamout04 X-Rspamd-Queue-Id: F3B2120030 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1/0KAD7ph+3Vtklma4cWlGaZGDvjoax82U= X-HE-Tag: 1777402296-843016 X-HE-Meta: U2FsdGVkX18rpObsFDcJUYY+/Q4809Xfdt7wG4uYomPQx79R5RIrySqRo1FCLoe7aIb1u/K8QFhrRjHFzvKVHbOLgajiPVCguro/oHAlRvuRKaR9DxswMYuVU/ssYHy1DrqrrLyNbhDeY33FGFORzFwlFM3AD30FctZ6ZXF68JdNkc+3KklnplMs7FMMHZous+suFYISo+hoKPGS7/qVN6YTh9OCo+PzkWkkINDDyiSMVzIBOKfvSQlYRXtlXI0P/2qnUEuhUXeVCHceU0omvUqIawBk++ZImz/1d2zfaT+//OEnaLZFItnwaclnrLy+lkWRcZICCXbPBinNBE3Nqpwd9d8+Ja1L On Fri, 13 Mar 2026 12:36:10 -0300 Wander Lairson Costa wrote: > On Fri, Mar 13, 2026 at 10:04:04AM +0100, Peter Zijlstra wrote: > > On Thu, Mar 12, 2026 at 02:19:15PM -0300, Wander Lairson Costa wrote: > > =20 > > > > That's significant bloat, for really very little gain. Realistically > > > > nobody is going to need these. > > > > =20 > > >=20 > > > Of course, I can't speak for others, but more than once I debugged is= sues > > > that those tracepoints had made my life far easier. Those cases convi= nced > > > me that such a feature would be worth it. But if you don't see > > > value and will reject the patches no matter what, nothing can be done, > > > and I will have to accept defeat. =20 > >=20 > > If distros are going to enable this, I suppose I'm not going to stop > > this. But I do very much worry about the general bloat of things, there > > are a *LOT* of preempt_{dis,en}able() sites. > > =20 >=20 > We plan to enable these tracepoints in the RHEL kernel-rt to track > extended non-preemptible states that cause high latencies. These > issues occasionally surface in customer OpenShift deployments, where > deploying a custom debug kernel is highly impractical. Having these > tracepoints available in the distribution kernel would be handful for > debugging these production systems. That said, I expect enabling this > feature to be the exception rather than the rule =E2=80=94 most distribut= ion > kernels would leave it disabled. Is this work going to continue? Or should I just change the status to "reject" in patchwork? -- Steve