From nobody Mon Feb 9 20:43:23 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 957F6304BB3; Wed, 1 Oct 2025 14:48:40 +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=1759330120; cv=none; b=V8TsMS98z9+kTn89/vJsx1bIyZUL/5MNSNAnCWbEUqwhpyQ/RUs5wq7R2qF9bVIBIQFVKuKxh98otJ8k87Zslq1E9inN/kxh5Y+Xq4BkoI1656F1tnjmmAohAXFwSRLzDe7Y1TO6KRp/xzdfy128FX9bdQIUFJNvK6DWAN5QY+U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759330120; c=relaxed/simple; bh=pdnTyZTL7oQ5jSpDQHBWEglBgEqYI4vFkpmgL1RNbu4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pSs0qUeryIJCE9UIB04zu6SP5jzmtVYUxxp3fCOBZZRQD3QOFoAT2vgUCaUZZnmmWXLeWcHjoshE26ysvyDLERohsKX4VxBkG8CO5QlksHQxuCWj40kedu+J2w8Z1d07i4BzBK/BNVBZHVke65veGWKephk4Dvl/LtJZ43MHYFs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a0+AuOus; 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="a0+AuOus" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04578C116D0; Wed, 1 Oct 2025 14:48:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759330120; bh=pdnTyZTL7oQ5jSpDQHBWEglBgEqYI4vFkpmgL1RNbu4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a0+AuOus2VUJ6A77QBhQkKFyKvAaLi4uJn0dGy/IzRTbIbqab1b1FwN8OVGNjqMVM L2/BQs39dPyC9L+0+ts8mI9rWqQjaY446jMGc4rLaOi0XRWj+FqnItuoB1IfH4rZjm h+H0c5Rbec4yOh9NECV/ua8m2HxJz3nIfIheRADNI1Ie/8R0eokTS96xebG7cLUuPY Bv40CVHy37zauyt8zywHK3LYEh8nKZHJPr1GurkgXSgXEOVJWqBs10TvccyTa9OMk6 N9hnPpOUNbeiqQEAbKlXi3URVLetqfAgYRDf13NCB8ezhC2WxoEUNYKM/oURba77YZ +HrWs402CM68g== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 8523ACE147E; Wed, 1 Oct 2025 07:48:34 -0700 (PDT) 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 v2 14/21] srcu: Make grace-period determination use ssp->srcu_reader_flavor Date: Wed, 1 Oct 2025 07:48:25 -0700 Message-Id: <20251001144832.631770-14-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <7fa58961-2dce-4e08-8174-1d1cc592210f@paulmck-laptop> References: <7fa58961-2dce-4e08-8174-1d1cc592210f@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 9869a13b876342..c29203b23d1ad7 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