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 D7BBB22A7E7; Mon, 2 Jun 2025 14:57:48 +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=1748876269; cv=none; b=qgEZ6q+g6sDhE/L4GcQ50YzIZ1df96EuoEnwA4XbhXOlMSWbaQOoSK5KFxcf+5SZckFnQ8rM69c7ngHNDXruDPIlQYw/jjipN2MabBX88b4lgCWepHT0V1sTE48xO4GBa77biIyXcPPa+VYxf9evbaFUfxvM1QhOy+FQid1cPR4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748876269; c=relaxed/simple; bh=7/GwFnUoybapJR599zoM5MB4TOiyfiBtcDw/J/8MSmo=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=oGzJWkhRTcyld3OaNiRSLDcggp/XSHeKDdIfRtDJZsbHbKPDQC5o94OfJwFmkvbXe7jJahKXPqvHsxys0TEGPY1QnDt53tmau9ayluTte/49dDVw8V5pHylKq2r2FE1wELUo4Afl0JDlA5zbBz4WRx5HW7vhpnf7GtBXmBrFL38= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FOtXMxjN; 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="FOtXMxjN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38107C4CEEE; Mon, 2 Jun 2025 14:57:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748876268; bh=7/GwFnUoybapJR599zoM5MB4TOiyfiBtcDw/J/8MSmo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=FOtXMxjNqidmvV5l1IZT/jKSFalSgXfIiBmU1qww2nUxJU3a2IrLLW37w5mQUwBc0 om3LXLou1Ks79KyuOO98VTP0vWd7h1nPu284l2KXaZ2YxkNR7uOL7Gzva0A9Og4lZ7 JdilPQYiar0U/MiuFEPq89clqDTU9GFliG3oVHNuRiWWsSLZ+IcBojP61u+MuGkq1G XAlSQTt0EDb3mU6BovKT3loZUNbEvTfHSXgPNBFWRtheybXD0xktVcGobRrNjiw0aU Hv9JEJZXEEE/jiHHuf1Rc2F9mmX3yaJEWmgqqzozIHLa1aFAcIrJaZlVmTxpNXASfj RHhDs63c1vu5w== Date: Mon, 2 Jun 2025 07:57:47 -0700 From: Jakub Kicinski To: Breno Leitao Cc: Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Tejun Heo , Andrew Morton , Shuah Khan , horms@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, gustavold@gmail.com, Usama Arif , linux-kselftest@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH net-next v2 0/4] netconsole: Optimize console registration and improve testing Message-ID: <20250602075747.5e659655@kernel.org> In-Reply-To: <20250602-netcons_ext-v2-0-ef88d999326d@debian.org> References: <20250602-netcons_ext-v2-0-ef88d999326d@debian.org> Precedence: bulk X-Mailing-List: linux-kselftest@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 Mon, 02 Jun 2025 03:34:40 -0700 Breno Leitao wrote: > During performance analysis of console subsystem latency, I discovered that > netconsole registers console handlers even when no active targets exist. > These orphaned console handlers are invoked on every printk() call, get > the lock, iterate through empty target lists, and consume CPU cycles > without performing any useful work. > > This patch series addresses the inefficiency by: > > 1. Implementing dynamic console registration/unregistration based on target > availability, ensuring console handlers are only active when needed > 2. Adding automatic cleanup of unused console registrations when targets > are disabled or removed > 3. Extending the selftest suite to cover non-extended console format, > which was previously untested > > The optimization reduces printk() overhead by eliminating unnecessary > function calls and list traversals when netconsole targets are not > configured, improving overall system performance during heavy logging > scenarios. Ah, I wasn't very clear, full form letter at the end. But also the tests seem to have failed now: https://netdev.bots.linux.dev/contest.html?branch=net-next-2025-06-02--12-00&executor=vmksft-net-drv&pw-n=0&pass=0 ## Form letter - net-next-closed Linus has already merged our PR with features for v6.16. net-next is closed for new drivers, features, code refactoring and optimizations for the remained for the merge window. Please repost when net-next reopens after June 9th. RFC patches sent for review only are obviously welcome at any time. See: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#development-cycle -- pw-bot: defer pv-bot: closed