From nobody Tue Nov 26 07:34:47 2024 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 2A3681E7C1D; Mon, 21 Oct 2024 10:25:41 +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=1729506342; cv=none; b=tLie9bEyrbqirB+iUT8fk82C+4eyTYvMu9niSPG5F4UDyBSnNhzc5QqpdUl6lOaBPz6XiVy9F1NWJS6IRtO58ufVhVm1zO/GWYXm8q4OBCWQW0oEYJKX+H3zOvHoepv9PHvBYYlBTbTrMxfl13X5rXpNZ+OLA22MorDDuMO2VAU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729506342; c=relaxed/simple; bh=sc8jhN+g3bazvvXRQ1yzerYMsmvb+DSO6M7l748KWNM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=jZtddSxGZM46qB/sPPR7Bk1RgAG/dHjh9YS4BJ8pts+yQAd0Ta1gG5GsaDNpWnO8gL0elrQPolUMlxi/YoSNE8E3hn8mlziMguWGltAzEtApdQlOHKw3qidZKCOWb7NvjXFj4AuGqUa9xUfoI5j67vyeMx8braEsUv5sWqtHFr4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lZzbSBQc; 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="lZzbSBQc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CAE7DC4CEC3; Mon, 21 Oct 2024 10:25:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729506341; bh=sc8jhN+g3bazvvXRQ1yzerYMsmvb+DSO6M7l748KWNM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=lZzbSBQc2+bSfBSa+YylekSkUe/WIi+qG8ZDgwkdxuGQ8kmGGyHGHaKmfe/13z//T SqU/Ry1n54mntoVKwejzzEbkE2CCRBl5j/DcPbXQisLXLEIPYhbaQHuKZTNlyGjbMV YLCHEfaEKRF8J+Qkazzak7MwZaDLfxiJk6aJAi7q2TECGq5vTaBfAmcSZqlYGHZfLc 9KKWmH00Nx+5ZaLQcrPoTkotzRNSd96TnVfb7PBwGuxO4KbyULReI1hYCysjslzFYm x7R7/qVUHKjQ3Nf65vsBbWn4I0DYKjdb5Kw/FJWzW2q5iuXW0KwJqy1DebiwHgk0YT r4/Ljx55HWAdQ== From: "Matthieu Baerts (NGI0)" Date: Mon, 21 Oct 2024 12:25:27 +0200 Subject: [PATCH net 2/3] mptcp: remove unneeded lock when listing scheds Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20241021-net-mptcp-sched-lock-v1-2-637759cf061c@kernel.org> References: <20241021-net-mptcp-sched-lock-v1-0-637759cf061c@kernel.org> In-Reply-To: <20241021-net-mptcp-sched-lock-v1-0-637759cf061c@kernel.org> To: mptcp@lists.linux.dev, Mat Martineau , Geliang Tang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Gregory Detal , Shuah Khan Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, "Matthieu Baerts (NGI0)" , stable@vger.kernel.org X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=1273; i=matttbe@kernel.org; h=from:subject:message-id; bh=sc8jhN+g3bazvvXRQ1yzerYMsmvb+DSO6M7l748KWNM=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBnFiwb5DB1p3KgSrPWEztR8Un4u7jVwmAXFuTBv n3DLRPi+ZyJAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZxYsGwAKCRD2t4JPQmmg c+uHD/9p62xCprKBXbWLdGbx0fgrK90+4dPS30lanUOsqd6/tyuiaMHPIsTfpMdaWYaFLfXBQct 4wB4bQPmFaMV9zNdy5BNDR+PjAQ4NBrKzc4vVPVzFkMgaHk6ivnJvjOEDbjFlzUCqPdQS/Mh7ne ceFwVCdwDb2ao87QuxLmvIlT33QfaUgpJXydKmqs0hK4utjxOT1cH1DrkkawI+dDMpaLQVPkZ3D qXuc2Jre25UaylEDUMyft3Wlf64jKK1NlcuembIyxkT6PugriFjpit4c4qtrBp6wJXt8/1aMxzm UVAAWaBo+KKlJkx8kifoWh64fzVwEAu9MuivFm8Kdog0c0TqaYYuyGg2YCgHne+0Ubed3DZkLQ8 RtcOMDFtgmPdwDC7UCT1q4b+5lINxkoshqzMQl1VrLdDT1NIkD3+SZzhNwUFlY4SvO6XkRkEAmt WnC0+z3ZFKEu29GMx9D2BLVHSLVyP98O5kA7E/Kk2QdJl29GSFub8wieE4MZgSpeQpGMwIFUdPp FVOezhbF8GxSIT9zN286MLWxjpVTzReGx5Hw4UeklfoCKX493VULNrUoKDry6qXsbhgoDgFgSSV b2AotkxrijvmYryQXEoR+LFgQJM7VUAKAg/++Thk2sOFpKU9sGdIU+0BtTYek6WdnGbL7XxHMUH 9xI4guGWM8AjipA== X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 mptcp_get_available_schedulers() needs to iterate over the schedulers' list only to read the names: it doesn't modify anything there. In this case, it is enough to hold the RCU read lock, no need to combine this with the associated spin lock. Fixes: 73c900aa3660 ("mptcp: add net.mptcp.available_schedulers") Cc: stable@vger.kernel.org Suggested-by: Paolo Abeni Reviewed-by: Geliang Tang Signed-off-by: Matthieu Baerts (NGI0) Reviewed-by: Simon Horman --- net/mptcp/sched.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c index 78ed508ebc1b8dd9f0e020cca1bdd86f24f0afeb..df7dbcfa3b71370cc4d7e4e4f16= cc1e41a50dddf 100644 --- a/net/mptcp/sched.c +++ b/net/mptcp/sched.c @@ -60,7 +60,6 @@ void mptcp_get_available_schedulers(char *buf, size_t max= len) size_t offs =3D 0; =20 rcu_read_lock(); - spin_lock(&mptcp_sched_list_lock); list_for_each_entry_rcu(sched, &mptcp_sched_list, list) { offs +=3D snprintf(buf + offs, maxlen - offs, "%s%s", @@ -69,7 +68,6 @@ void mptcp_get_available_schedulers(char *buf, size_t max= len) if (WARN_ON_ONCE(offs >=3D maxlen)) break; } - spin_unlock(&mptcp_sched_list_lock); rcu_read_unlock(); } =20 --=20 2.45.2