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From: Jakub Kicinski <kuba@kernel.org>
To: Breno Leitao <leitao@debian.org>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Paolo Abeni <pabeni@redhat.com>, Tejun Heo <tj@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Shuah Khan <shuah@kernel.org>,
	horms@kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, gustavold@gmail.com,
	Usama Arif <usamaarif642@gmail.com>,
	linux-kselftest@vger.kernel.org, kernel-team@meta.com
Subject: Re: [PATCH net-next v2 0/4] netconsole: Optimize console registration and improve testing
Date: Mon, 2 Jun 2025 07:57:47 -0700	[thread overview]
Message-ID: <20250602075747.5e659655@kernel.org> (raw)
In-Reply-To: <20250602-netcons_ext-v2-0-ef88d999326d@debian.org>

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



      parent reply	other threads:[~2025-06-02 14:57 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-02 10:34 [PATCH net-next v2 0/4] netconsole: Optimize console registration and improve testing Breno Leitao
2025-06-02 10:34 ` [PATCH net-next v2 1/4] netconsole: Only register console drivers when targets are configured Breno Leitao
2025-06-02 10:34 ` [PATCH net-next v2 2/4] netconsole: Add automatic console unregistration on target removal Breno Leitao
2025-06-02 10:34 ` [PATCH net-next v2 3/4] selftests: netconsole: Do not exit from inside the validation function Breno Leitao
2025-06-02 10:34 ` [PATCH net-next v2 4/4] selftests: netconsole: Add support for basic netconsole target format Breno Leitao
2025-06-02 14:57 ` Jakub Kicinski [this message]

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