From nobody Fri Dec 19 16:03:30 2025 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 5F4F734887C; Wed, 5 Nov 2025 20:32:20 +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=1762374740; cv=none; b=pmZVsYVldsczmSGlWIM0Zo2BYg/Lq5FJnNhP0e5pitvwPNwL/ghf5AV/8i+fAhrF5WoNC6PhA6b7RfkVelyzvlLlRE6yKDzbrrr/j8ZrEVbwfhMdvRgCnyby+n5dMSarHbnS01kpVl654KxUGvce5hsD/pZdOakU5AQLiMZABM4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762374740; c=relaxed/simple; bh=Q0AKERJDbUSfsvDf4x7Le3CWRCQuSmTY0wgl6K/Nz6M=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=nhZwOT06pMixNBSd93XRVo/XNL+4KCrt/0vt8T1ctJpwoCDvXOSZTRWcSKAM4mWYfylAGxk1AjSrFJg0CZz4wD9VPN0Bp3atiw1XxcP4v5Ux2Y4Mc7ntjyIQUSEcyjCZaDFdVazXvsFhQKQ+6BRa/O78lVDVa2AgO5wn7SMVYFo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a0zkxm8m; 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="a0zkxm8m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84E11C19421; Wed, 5 Nov 2025 20:32:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762374739; bh=Q0AKERJDbUSfsvDf4x7Le3CWRCQuSmTY0wgl6K/Nz6M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a0zkxm8mFO7vLeGUlhKNDvzrqqCJ0EWgw4UvfOtFP5952B63y1fRdQgZS32OnmQR0 O7EX8EbBUF6VtkPbhTj4J7M29E3fWzNM8z/CCkQGDDjRji/D7xUzKRJjlRsklWNjhc s33zlrIlL1d9heXeSugnO7FO7hwDXcBoXzxaiFj6CgoewRfxYandFy8y483vOAONwB pANzmEdIGy7GbXTtZa45tKpWwo9GoVIKILZc5/PCTrgYFqUe3FVil29mmRdvqcsvHO u8191369DjGEm8BLIiLxNW96O/Z8XQv4ZEhgiLV5+MpqS08sJtMM7W36n9EI2eqq1Y zj0NoOWyv63bQ== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 916D9CE0EBB; Wed, 5 Nov 2025 12:32:18 -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 v2 05/16] srcu: Make grace-period determination use ssp->srcu_reader_flavor Date: Wed, 5 Nov 2025 12:32:05 -0800 Message-Id: <20251105203216.2701005-5-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: 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