From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) (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 407F11339A4; Sun, 11 Jan 2026 22:10:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768169406; cv=none; b=TagIZ60qno5lcdrrIWy1A27GljbkqEdfwV6nM9ouKwbG8zh8AZEiVK+uI9+Ep5XRoCiBEneddOsxfMkuG5Ou484sYugeufzGrqm3uEFba/xMAA9dLHDPAaZ48eDfA2oU6gSnk8V+y4DjE5WBTWRCW9lR0tLniHHcZhFDvVoABvU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768169406; c=relaxed/simple; bh=8brB/gIotb0DWiWePfrKUYHLIGrO47udlc70WW+Ne0E=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=LA/3q3hoKfI/FKswEc+Lu4LjciP4lIG94DYN8Gv0gOL/1umRCdD6frbXSlnTcOzYNFdtRBv9xwVdOc94fIoDHmuwTrrEaHVTiYjw797QF3N1hgb+EB6ozQ6pfF/FDWGVpsL0St8qC74HUrOQ/JF7g6tg8ixUaS9MnGU5x8Sr2fU= 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=216.40.44.12 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 omf15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id C0D9A161286; Sun, 11 Jan 2026 22:09:56 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf15.hostedemail.com (Postfix) with ESMTPA id 863631A; Sun, 11 Jan 2026 22:09:54 +0000 (UTC) Date: Sun, 11 Jan 2026 17:09:53 -0500 From: Steven Rostedt To: Alexei Starovoitov Cc: Mathieu Desnoyers , LKML , Linux trace kernel , bpf , Masami Hiramatsu , "Paul E. McKenney" , Sebastian Andrzej Siewior , Thomas Gleixner Subject: Re: [PATCH v5] tracing: Guard __DECLARE_TRACE() use of __DO_TRACE_CALL() with SRCU-fast Message-ID: <20260111170953.49127c00@fedora> In-Reply-To: References: <20260108220550.2f6638f3@fedora> <20260109141930.6deb2a0a@gandalf.local.home> <3c0df437-f6e5-47c6-aed5-f4cc26fe627a@efficios.com> <20260109170028.0068a14d@fedora> <20260109173326.616e873c@fedora> <20260109173915.1e8a784e@fedora> <20260110111454.7d1a7b66@fedora> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-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-Rspamd-Queue-Id: 863631A X-Stat-Signature: moc7n7gme61qa88wc8cnoifmaq1zt7ed X-Rspamd-Server: rspamout05 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+fgY/X4vzJwIPhelmP5ZQGGi/VoABAAq8= X-HE-Tag: 1768169394-114868 X-HE-Meta: U2FsdGVkX19V6IrRjUZy1KASoCP9WyyBPXG1m7hVp8NAkVx3Be8qztIDSmfGd7IWbbf5rxAAmG4NWPj2EcOT+AN8JEuw6wPeL7EaZ8gL/ZtkQyo4vUf3kpsDyJgMRPy7XBJP1Y0eEl6YE7nzIRMPXUVPRRgI1QJj2ZDDyj/OTO7VLeKsLMIKndJk6mMRbYEcQVApVjvnLB8xnVQpSThdjta4bbu7E9b/TQSfRsRevezPdndMYLngx1a2fbCTZX2gSIgRQRIC3g8grOKEOKcF/z7KoH0jNp/Hbnw9XZakutLMoAEO1RHPbIM7/ofMNvP8j/SFEWGYq0VH7avSMzDGUZiThSc/z11Y On Sun, 11 Jan 2026 12:04:51 -0800 Alexei Starovoitov wrote: > The diff has nothing to do with bpf needs and/or bpf internals. > It's really about being a good citizen of PREEMP_RT. > bpf side already does migrate_disable, > rcu_read_lock, srcu_fast/task_trace when necessary. > Most of the time we don't rely on any external preempt state or rcu/srcu. > Removing guard(preempt_notrace)(); from tracepoint invocation > would be just fine for bpf. Simple remove will trigger bug > on cant_sleep(), but that's a trivial fix. Oh, so you are OK replacing the preempt_disable in the tracepoint callbacks with fast SRCU? Then I guess we can simply do that. Would it be fine to do that for both RT and non-RT? That will simplify the code quite a bit. -- Steve