linux-kernel - Re: [PATCH net-next V2 3/3] net/mlx5e: Make PCIe congestion event thresholds configurable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250711163018.335ea0f5@kernel.org>
Date: Fri, 11 Jul 2025 16:30:18 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: Tariq Toukan <tariqt@...dia.com>
Cc: Eric Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>,
 Andrew Lunn <andrew+netdev@...n.ch>, "David S. Miller"
 <davem@...emloft.net>, Saeed Mahameed <saeed@...nel.org>, Gal Pressman
 <gal@...dia.com>, "Leon Romanovsky" <leon@...nel.org>, Saeed Mahameed
 <saeedm@...dia.com>, Mark Bloch <mbloch@...dia.com>, Jonathan Corbet
 <corbet@....net>, <netdev@...r.kernel.org>, <linux-rdma@...r.kernel.org>,
 <linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>, Dragos Tatulea
 <dtatulea@...dia.com>
Subject: Re: [PATCH net-next V2 3/3] net/mlx5e: Make PCIe congestion event
 thresholds configurable

On Thu, 10 Jul 2025 09:51:32 +0300 Tariq Toukan wrote:
> Add a new sysfs entry for reading and configuring the PCIe congestion
> event thresholds. The format is the following:
> <inbound_low> <inbound_high> <outbound_low> <outbound_high>
> 
> Units are 0.01 %. Accepted values are in range (0, 10000].
> 
> When new thresholds are configured, a object modify operation will
> happen. The set function is updated accordingly to act as a modify
> as well.
> 
> The threshold configuration is stored and queried directly
> in the firmware.
> 
> To prevent fat fingering the numbers, read them initially as u64.

no sysfs, please :S Could you add these knobs to devlink?

> +	if (config) {
> +		*config = (struct mlx5e_pcie_cong_thresh) {
> +			.inbound_low = MLX5_GET(pcie_cong_event_obj, obj,
> +						inbound_cong_low_threshold),

Why are you overwriting the whole struct. It'd literally save you 
1 char of line length and 2 lines of LoC to pop a config-> in front
of each of these assignments...

The "whole struct assignment" really only makes sense when you
intentionally want to set the remaining members to 0 which is likely
very much _not_ what you want here, was the config struct ever to be
extended..

I know the cool new language features are cool but..

> +			.inbound_high = MLX5_GET(pcie_cong_event_obj, obj,
> +						inbound_cong_high_threshold),
> +			.outbound_low = MLX5_GET(pcie_cong_event_obj, obj,
> +						 outbound_cong_low_threshold),
> +			.outbound_high = MLX5_GET(pcie_cong_event_obj, obj,
> +						  outbound_cong_high_threshold),
> +		};
> +	}