Re: [PATCH 02/13] wifi: mwifiex: Use default @max_active for workqueues

From: Brian Norris
Date: Wed May 10 2023 - 14:10:05 EST


On Mon, May 08, 2023 at 03:50:21PM -1000, Tejun Heo wrote:
> These workqueues only host a single work item and thus doen't need explicit
> concurrency limit. Let's use the default @max_active. This doesn't cost
> anything and clearly expresses that @max_active doesn't matter.
>
> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
> Cc: Amitkumar Karwar <amitkarwar@xxxxxxxxx>
> Cc: Ganapathi Bhat <ganapathi017@xxxxxxxxx>
> Cc: Sharvari Harisangam <sharvari.harisangam@xxxxxxx>
> Cc: Xinming Hu <huxinming820@xxxxxxxxx>
> Cc: Kalle Valo <kvalo@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
> Cc: linux-wireless@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx

Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>

I'll admit, the workqueue documentation sounds a bit like "max_active ==
1 + WQ_UNBOUND" is what we want ("one work item [...] active at any
given time"), but that's more of my misunderstanding than anything --
each work item can only be active in a single context at any given time,
so that note is talking about distinct (i.e., more than 1) work items.

While I'm here: we're still debugging what's affecting WiFi performance
on some of our WiFi systems, but it's possible I'll be turning some of
these into struct kthread_worker instead. We can cross that bridge
(including potential conflicts) if/when we come to it though.

Thanks,
Brian