From nobody Mon Feb 9 15:07:43 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 932B2153BED; Mon, 3 Nov 2025 07:19:12 +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=1762154352; cv=none; b=WbgU0fBj7qvCM9zZLRGz4dIyG8nMWi7fQpSgCvxbkIa5KTVq5qt/Ns/3aujIGR9xhSJB0OHeesTphRC8ShjbUQVtc7JN+YbhKowu0MMn0uvOBSyVSt0xFF1tMGIMFNFFoRPLwGl3c8DjSXTOMt/8U5dH+hQzsXCI3yLnoPozeKY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762154352; c=relaxed/simple; bh=Q0AKERJDbUSfsvDf4x7Le3CWRCQuSmTY0wgl6K/Nz6M=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=osSOK/cWXFSH6GA1HXq8yobNLc7HHjwWl6+CDCi8HQbq+Xxwvk8Phb7299HBKZrHRd4gQheDu5YY6H8r5/6iUxUDl49SikGgN/jDwdYJf4FWgJflLPMp+ssp5Q2XOELgka8rTdu0XZF8mV8N9O58rbezJWOPDu5GrekSPYxrT9E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jnBM3d/E; 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="jnBM3d/E" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 382EBC4AF0B; Mon, 3 Nov 2025 07:19:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762154352; bh=Q0AKERJDbUSfsvDf4x7Le3CWRCQuSmTY0wgl6K/Nz6M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jnBM3d/E+ybQzkcBC9iT6IUwRUfd3ufuyVxc8Fl/nEFWDPKw5MGD2U9mumDTjbuL+ xSsCTxgqlHeH+1tAy98A17kJgirQ/bMgYUTzWldFY+dzypYu3+IpNHADmPW87XwZ0u EzZ/wA8a1h4HRdVcoIp/lRW6vNwHgiJXu5ru/ojh/3gp63fDNK/d7v6ml0pg37vOeP HLIGWXyg2ZmxfN69zi2K65i1OoskCrL+6PY2Qv9NJlcMJyJM7XhzbCPWgV/eKGHzj0 GJprz6KUBoUPCyPDbk0c5qsmpT8dKZk5k4NGhFe09KomwZmYkUzoM/sbdaQE/082Z+ BiLd3EwBVRNMA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 84200CE0FF9; Sun, 2 Nov 2025 13:44:37 -0800 (PST) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, "Paul E. McKenney" , Mathieu Desnoyers , Sebastian Andrzej Siewior , bpf@vger.kernel.org Subject: [PATCH 05/19] srcu: Make grace-period determination use ssp->srcu_reader_flavor Date: Sun, 2 Nov 2025 13:44:22 -0800 Message-Id: <20251102214436.3905633-5-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <082fb8ba-91b8-448e-a472-195eb7b282fd@paulmck-laptop> References: <082fb8ba-91b8-448e-a472-195eb7b282fd@paulmck-laptop> 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" This commit causes the srcu_readers_unlock_idx() function to take the srcu_struct structure's ->srcu_reader_flavor field into account. This ensures that structures defined via DEFINE_SRCU_FAST( or initialized via init_srcu_struct_fast() have their grace periods use synchronize_srcu() or synchronize_srcu_expedited() instead of smp_mb(), even before the first SRCU reader has been entered. Signed-off-by: Paul E. McKenney Cc: Mathieu Desnoyers Cc: Steven Rostedt Cc: Sebastian Andrzej Siewior Cc: --- kernel/rcu/srcutree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 9869a13b8763..c29203b23d1a 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -490,7 +490,7 @@ static bool srcu_readers_lock_idx(struct srcu_struct *s= sp, int idx, bool gp, uns static unsigned long srcu_readers_unlock_idx(struct srcu_struct *ssp, int = idx, unsigned long *rdm) { int cpu; - unsigned long mask =3D 0; + unsigned long mask =3D ssp->srcu_reader_flavor; unsigned long sum =3D 0; =20 for_each_possible_cpu(cpu) { --=20 2.40.1