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Date:   Wed, 10 May 2023 11:09:55 -0700
From:   Brian Norris <briannorris@chromium.org>
To:     Tejun Heo <tj@kernel.org>
Cc:     jiangshanlai@gmail.com, linux-kernel@vger.kernel.org,
        kernel-team@meta.com, Amitkumar Karwar <amitkarwar@gmail.com>,
        Ganapathi Bhat <ganapathi017@gmail.com>,
        Sharvari Harisangam <sharvari.harisangam@nxp.com>,
        Xinming Hu <huxinming820@gmail.com>,
        Kalle Valo <kvalo@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 02/13] wifi: mwifiex: Use default @max_active for
 workqueues
Message-ID: <ZFvd8zcPq4ijSszM@google.com>
References: <20230509015032.3768622-1-tj@kernel.org>
 <20230509015032.3768622-3-tj@kernel.org>
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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@kernel.org>
> Cc: Amitkumar Karwar <amitkarwar@gmail.com>
> Cc: Ganapathi Bhat <ganapathi017@gmail.com>
> Cc: Sharvari Harisangam <sharvari.harisangam@nxp.com>
> Cc: Xinming Hu <huxinming820@gmail.com>
> Cc: Kalle Valo <kvalo@kernel.org>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: linux-wireless@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org

Reviewed-by: Brian Norris <briannorris@chromium.org>

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