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Date:   Thu, 30 Mar 2023 13:08:28 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Eric Dumazet <edumazet@google.com>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        eric.dumazet@gmail.com
Subject: Re: [PATCH net-next] tcp: tsq: avoid using a tasklet if possible
Message-ID: <20230330130828.4aa7f911@kernel.org>
In-Reply-To: <20230330192534.2307410-1-edumazet@google.com>
References: <20230330192534.2307410-1-edumazet@google.com>
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On Thu, 30 Mar 2023 19:25:34 +0000 Eric Dumazet wrote:
> Instead of always defer TCP Small Queue handling to a tasklet
> we can try to lock the socket and immediately call tcp_tsq_handler()
> 
> In my experiments on a 100Gbit NIC with FQ qdisc, number of times
> tcp_tasklet_func() is fired per second goes from ~70,000 to ~1,000.
> 
> This reduces number of ksoftirqd wakeups and thus extra cpu
> costs and latencies.

Oh, you posted already. LMK what you think about other locks,
I reckon we should apply this patch... just maybe around -rc1
to give ourselves plenty of time to find the broken drivers?