From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) (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 102FA37E316; Tue, 14 Jul 2026 11:24:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784028288; cv=none; b=rbeSTce6R/82UmqaLCa2trIeU2uizkSCyVkGWoMfBNAihjqqgBBxOiMMpRp7goXdKPsOROUmbm4AqkZYIIX0VkeOBAabTnG6+UGvRM3jgxTSDJKrrAi6aiONeUqyipU6aEyeTGivtLmfjwJYJXR5WLywWg6/7RsVYhmYmI1Z7C0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784028288; c=relaxed/simple; bh=xwnVB3jSCMT0uTIjvCYcV+Y7V8WSloPYMu8UDRYcicc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gBn59dxmaPtWD20BmH6cgW9Jpaq624Yu82VeBQm4PRjtjCYBf6wk+qhOrBEUQCObHHx0eNRf72akSXqQ2yXWjmaYHxZp+aehGBvYKzQkf8XQl86dBbqryY6XyWs4xOb4ZbR+mO+ftWL/NwJgeZQ8ztnPGtyafpif3CaDazk2Vnw= 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=216.40.44.17 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 omf11.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 812A3A0376; Tue, 14 Jul 2026 11:24:39 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf11.hostedemail.com (Postfix) with ESMTPA id 9B6BB2002F; Tue, 14 Jul 2026 11:24:37 +0000 (UTC) Date: Tue, 14 Jul 2026 07:24:40 -0400 From: Steven Rostedt To: Tengda Wu Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tracing: Add mutex to trace_parser to fix concurrent write races Message-ID: <20260714072440.4ff92b33@gandalf.local.home> In-Reply-To: <059bee5e-6852-4afb-a993-dd5ddcd86d3e@huaweicloud.com> References: <20260713134640.708323-1-wutengda@huaweicloud.com> <20260713153624.48fc4be4@robin> <20260713221318.63f741ad@gandalf.local.home> <059bee5e-6852-4afb-a993-dd5ddcd86d3e@huaweicloud.com> 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: a6gqa6tj8wnp1t4puheieg117de5b1d5 X-Rspamd-Server: rspamout02 X-Rspamd-Queue-Id: 9B6BB2002F X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX19Yihg6SLCzDXeH97maO2Jf5p+X69uTAOU= X-HE-Tag: 1784028277-762485 X-HE-Meta: U2FsdGVkX1/fKPjLnEThu8XEikzu1iNLPZXjS53UWV15qvagdhumby6QBqqKdu0tvpcTijkkmzvDM1npMOJaWTwUUwYBjIG+dAG9OjYyD36ZG2wGlP7BREtWNc8KevBDktizfvA0FkI8+jF40xMvd3frIP0wUFPc5b+Dqop5sdFbjxS6307siLAqhZq8Hn2KE64cvZSp5dqBLMAnpQclKzTopzovISlPUgBdf1OXKTdiEHe2SL0OqL7KlFq9Uiy01JD8PXg/Qm+kXPlTMJHYuqT2WR/Kr3TuGXs7g38Tjm2+TqIbLZVNCjUrIuPMsib63wqs+nkPmfwrqWFfWDuPp+51SaHjfrvb On Tue, 14 Jul 2026 18:16:26 +0800 Tengda Wu wrote: > _Approach 3_: As you suggested earlier, build on v1 but add proper lockdep > assertions to enforce that the parser lock is held by all callers, > regardless of how the parser is used. > > Approach 3 seems cleaner and more straightforward. I thought about having a global lock as writes to tracefs are very much a slow path, but I think Approach 3 is probably the most "correct" fix. Yeah, let's go with that. Thanks, -- Steve