From nobody Thu Oct 2 03:30:47 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 F0B45251791; Tue, 23 Sep 2025 14:22:04 +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=1758637325; cv=none; b=S+xRzUO2IFpAvWvIIiAh9g5++zS5HUGbPCKBi6BtgBCFKMPh+aS4yUGeksWy/f8QqNRchoZnbcoltgy64GwK/jVdGHtLcBiFbOUAV/Y+/ezMxFWtHa0zL1pPp2fIvIJuwLTVfztrbBFamEIDuH1uKJ5unytuCVWYc3pRTNNnREg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758637325; c=relaxed/simple; bh=/9ihPRofiSX+oBfCmJpcNKAf4WsfpDFWiCi2HWwyMDs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=q2cllku6hJ5MMxZHoaMeksYPSU7xy6ZKmRqJD05xXUzwzB+e68vhQEb06EKRZ3TmvaBDIftRB5EdSCWaw7xIs5xaN9Fk1R6lYTSBuJ0clocWWcbJwvFsEws4oFJv9hYVa2wsa1Wy4kpGVqPwY9DUgpHIQ8ZSYht4+dQWnP2DB60= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kI1FhNaC; 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="kI1FhNaC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D79E1C116C6; Tue, 23 Sep 2025 14:22:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758637324; bh=/9ihPRofiSX+oBfCmJpcNKAf4WsfpDFWiCi2HWwyMDs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kI1FhNaCOg3rQqc/Vkz+IMTFsm+YnYuQHpsjLc4gN0jB/p40ijLyyJdRORo3YXiRD /q0hrBoBddaB/VoZIMTYubFS0r+eSqVHjDV7c61wtZrmGMDiR0c82rKQ4kIaQxpAUJ s70HwmmQ0kcDEsaismPnRf7SszVk0skEmreJWyGFVzGksAp8oOCKrWtTplv9zOWsXF /VbkkBR5KETt9iv9Ti6eN8IKQxhxJ0CGODpx8ivLkc+PSOm3xbd6+oF5Tw14XFJyyd qUddy2TAKMCN5+U1RAGATW8bBep++ISLDIFhP5HrM1Y56l8Wu5hirTBTqPMOM9CNf+ FWo+SIfflWgFg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 0F626CE1775; Tue, 23 Sep 2025 07:20:38 -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 29/34] srcu: Make grace-period determination use ssp->srcu_reader_flavor Date: Tue, 23 Sep 2025 07:20:31 -0700 Message-Id: <20250923142036.112290-29-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <580ea2de-799a-4ddc-bde9-c16f3fb1e6e7@paulmck-laptop> References: <580ea2de-799a-4ddc-bde9-c16f3fb1e6e7@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 177f9ec1f926e1..8a871976c37dfe 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