From nobody Wed Feb 11 06:56:59 2026 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 B181217EBBD for ; Tue, 14 May 2024 16:14:57 +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=1715703297; cv=none; b=HlNduO3tcS8+6sghiEwTQiay6SAp3sxLMhLBd268ePR3HrzHH0KkYKMcb3n9lcn6cYKBHdNF9J5arPP2ntAL0y1k07oPrSLklXf7rpg1KD1cZGirHgcqFSN8PaMXsbalCZjcyVuoEn6D2VLU6slyn0hWSgqcTalqzFT8hNgA19s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715703297; c=relaxed/simple; bh=xpNUKXxZg5qc/m0w5UgHuX1xFL6MNEp0QCdXc0cQBDo=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=uPnv+GDBM0NLNS+HqORsgd22/37I0DejxJXGs+tbc0O6q74MdRvcj21vrST2xmLQ0Kw2fMhXdoCPdibsR+DSW9U7i8jZsZUYtY3tyruflc7fuJlX/12bdXwv1uQQZDWTShyi2ubar4+KvQQT0HnuRx+LkuLAIc/9s+4hoMEfmpw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8FC69C4AF09; Tue, 14 May 2024 16:14:57 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1s6uoE-00000003t3U-1G0w; Tue, 14 May 2024 12:15:22 -0400 Message-ID: <20240514161522.157427484@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 14 May 2024 12:14:40 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Jakub Kicinski , Alexei Starovoitov , Chris Mason , "Paul E. McKenney" Subject: [for-next][PATCH 2/7] ftrace: Use asynchronous grace period for register_ftrace_direct() References: <20240514161438.134250861@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Paul E. McKenney" When running heavy test workloads with KASAN enabled, RCU Tasks grace periods can extend for many tens of seconds, significantly slowing trace registration. Therefore, make the registration-side RCU Tasks grace period be asynchronous via call_rcu_tasks(). Link: https://lore.kernel.org/linux-trace-kernel/ac05be77-2972-475b-9b57-56= bef15aa00a@paulmck-laptop Reported-by: Jakub Kicinski Reported-by: Alexei Starovoitov Reported-by: Chris Mason Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Paul E. McKenney Signed-off-by: Steven Rostedt (Google) --- kernel/trace/ftrace.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 3951c0d0ec63..f9223513414a 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5366,6 +5366,13 @@ static void remove_direct_functions_hash(struct ftra= ce_hash *hash, unsigned long } } =20 +static void register_ftrace_direct_cb(struct rcu_head *rhp) +{ + struct ftrace_hash *fhp =3D container_of(rhp, struct ftrace_hash, rcu); + + free_ftrace_hash(fhp); +} + /** * register_ftrace_direct - Call a custom trampoline directly * for multiple functions registered in @ops @@ -5464,10 +5471,8 @@ int register_ftrace_direct(struct ftrace_ops *ops, u= nsigned long addr) out_unlock: mutex_unlock(&direct_mutex); =20 - if (free_hash && free_hash !=3D EMPTY_HASH) { - synchronize_rcu_tasks(); - free_ftrace_hash(free_hash); - } + if (free_hash && free_hash !=3D EMPTY_HASH) + call_rcu_tasks(&free_hash->rcu, register_ftrace_direct_cb); =20 if (new_hash) free_ftrace_hash(new_hash); --=20 2.43.0