From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3FCB623BD1B; Wed, 4 Mar 2026 01:48:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772588916; cv=none; b=VcVM6PH/9H5KxYtzxZp7ZOOV5AQwXVZnngOU62g1tIi6ehFFeapdsOuv2nNw5xYNVDoELrFz3k9tbWnoKHUoEp6Th5oJVaRPSk6ga/FGR3XtlwpzXu7SyIsHzdfarLBFT2NmVMQn2kykgjn0DPrYtrRuhFQMqeiVtr2kPNzR+G8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772588916; c=relaxed/simple; bh=Fa9nLYOGHIHdefzwWFDP3AaDErCLowrkNcenetv9BXA=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=InskvX8b0+yeNRuMTU87a02TMn8Zf38NOo2spxF7yj8iPZhRHygm0qz0lxBbW6OU4SQwU0zIlYQk/KKbYtE3Y+XT4dIWWRrTUniFlzvSs5tAIig0BckK/FrVPNPhEgSqs5M90Ims0a6o21LjSe4wcmn0luWUnZIZBWMveGAItPU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ul6QKCwK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ul6QKCwK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B753C116C6; Wed, 4 Mar 2026 01:48:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772588915; bh=Fa9nLYOGHIHdefzwWFDP3AaDErCLowrkNcenetv9BXA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ul6QKCwK91bg0QFzXIybQTpXMCy+daPHWbucxDZ8U6cBI8003uei0PfqUZjxrbwpr h4ISCY5bSowbeNvsIeA75NRwY5gbKtCXGz5ob4eIY8QXS3j2u0ECwfnv59HXAqRsu7 A0uW2eY2MwPbeR20MQ2IWP6KQsm+RoGdUrz7kQ13PImqS6MgogXoFpeE0WffleaFUZ aRlUXVK90xP0KgZZF3C7/bI4OTHo4YErekJTjNrIzYpmWlyuIPHxo+CFmgrzW/WWlb +D+PcltSc4al3z1VPsIxd4JfRb7/ciWogYG8f3gd9VJNKuc6XE/LLnwoOWSZRy574r qjUCEBwPmH5sg== Date: Wed, 4 Mar 2026 10:48:33 +0900 From: Masami Hiramatsu (Google) To: Steven Rostedt Cc: LKML , Linux Trace Kernel , Mathieu Desnoyers Subject: Re: [PATCH] ftrace: Disable preemption in the tracepoint callbacks handling filtered pids Message-Id: <20260304104833.7b157f3cd2ff911cbcf77660@kernel.org> In-Reply-To: <20260303093949.4210e854@gandalf.local.home> References: <20260302213546.156e3e4f@gandalf.local.home> <20260303131706.96057f61a48a34c43ce1e396@kernel.org> <20260303093949.4210e854@gandalf.local.home> X-Mailer: Sylpheed 3.8.0beta1 (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 On Tue, 3 Mar 2026 09:39:49 -0500 Steven Rostedt wrote: > On Tue, 3 Mar 2026 13:17:06 +0900 > Masami Hiramatsu (Google) wrote: > > > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c > > index 9928da636c9d..3b3aaf4831e9 100644 > > --- a/kernel/trace/trace_events.c > > +++ b/kernel/trace/trace_events.c > > @@ -1039,6 +1039,7 @@ event_filter_pid_sched_process_exit(void *data, struct task_struct *task) > > struct trace_pid_list *pid_list; > > struct trace_array *tr = data; > > > > + guard(preempt)(); > > pid_list = rcu_dereference_raw(tr->filtered_pids); > > trace_filter_add_remove_task(pid_list, NULL, task); > > > > @@ -1054,6 +1055,7 @@ event_filter_pid_sched_process_fork(void *data, > > struct trace_pid_list *pid_list; > > struct trace_array *tr = data; > > > > + guard(preempt)(); > > pid_list = rcu_dereference_sched(tr->filtered_pids); > > trace_filter_add_remove_task(pid_list, self, task); > > > > Yep. I can make them two different patches. Do you want me to take this as > your patch? I'll need a SoB from you then. I think we can combine those since it fixes the same commit. (just for bisectability) Signed-off-by: Masami Hiramatsu (Google) Thank you, > > -- Steve -- Masami Hiramatsu (Google)