From mboxrd@z Thu Jan 1 00:00:00 1970 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 4424B18C02D; Mon, 28 Oct 2024 22:53:15 +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=1730155996; cv=none; b=IB2TderYuoHrZnFarcsifN+FFfeW0wXhxJk+xUWnfTtKgvjBZ2RGB2qKxVE2XfK25X3xDLRmUEfMgWAojfvHNIKdAp1nFmYAckD9Eoxboww2rHOQ14PQfoFIDT0hx5YuTNQWcgG+bJntv/8ZHQbdv2q7li7ZTdnogTn0pBkk4vQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730155996; c=relaxed/simple; bh=HSm7l+dIvXw5CpFH9RjYr70BRYS7SglQogW4EmAuIbg=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gjTgjWwbyWXYsMetmJ+rlMNgEmw7j2b/qb9WqWzbh/fCqSwh5ZLe6YK9gQGtKfOjej951tGO2T/T2ZsP3CAdbzM6QL+luTPb7QriAdW8SKv4BNpjSEbspydfPEuBHGQgRzLPHStowpTwaJ7PFa7eh/AFI4RzhYxSPTSpQ9zPLTk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W7BBxUbC; 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="W7BBxUbC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19080C4CECD; Mon, 28 Oct 2024 22:53:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730155995; bh=HSm7l+dIvXw5CpFH9RjYr70BRYS7SglQogW4EmAuIbg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=W7BBxUbCUrpS1iA89avK18t+SK0ADv78ODLgmI54adILN5wvAAJVYJybo+/S0hL2f RZsX9vVZN2k1yUROABIxWJkyZvyjSw/3FKX3Szs4lwGgdlSdopCs/198Sv1kDxiLnp +UHpZk8GJMUbhcsk7z2latVFM/yF6i0bS0SFMMkLxVY9lMwdhx9BtuveqECxhc3jJ3 I2lr9iTGr4PpHojDmiwszyLUo1XigcWGUeuwUNN4kGZABsguU+bSMck91rBaNuKbYU fRI+h1qqMRKi2+DndcTcELVb8Pi7bPMaClCB7ALR1nW9X/JbbnoG61FP7/T2PU0EKn eEsV/9WhutF/A== Date: Mon, 28 Oct 2024 15:53:14 -0700 From: Jakub Kicinski To: Matthieu Baerts Cc: Simon Horman , mptcp@lists.linux.dev, Mat Martineau , Geliang Tang , "David S. Miller" , Eric Dumazet , Paolo Abeni , Gregory Detal , Shuah Khan , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH net 2/3] mptcp: remove unneeded lock when listing scheds Message-ID: <20241028155314.006f9063@kernel.org> In-Reply-To: <4ca239db-6a05-4735-916c-73cee0ee22a0@kernel.org> References: <20241021-net-mptcp-sched-lock-v1-0-637759cf061c@kernel.org> <20241021-net-mptcp-sched-lock-v1-2-637759cf061c@kernel.org> <20241023122128.GT402847@kernel.org> <4ca239db-6a05-4735-916c-73cee0ee22a0@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 23 Oct 2024 16:13:36 +0200 Matthieu Baerts wrote: > On 23/10/2024 14:21, Simon Horman wrote: > > On Mon, Oct 21, 2024 at 12:25:27PM +0200, Matthieu Baerts (NGI0) wrote: > >> 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) > > > > I do wonder if it would be more appropriate to route this via net-next > > (without a fixes tag) rather than via net. But either way this looks good > > to me. > Good point. On one hand, I marked it as a fix, because when working on > the patch 1/3, we noticed these spin_(un)lock() were not supposed to be > there in the first place. On the other hand, even it's fixing a small > performance issue, it is not fixing a regression. > > I think it is easier to route this via -net, but I'm fine if it is > applied in net-next. I agree with Simon's initial response. Let's not blur the lines. Please re-queue for net-next, I'll apply the rest. BTW thanks a lot for proactively fixing the CONFIG_PROVE_RCU_LIST splats!