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Date: Thu, 07 Mar 2024 12:57:55 -0500
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: Marcelo Tosatti <mtosatti@redhat.com>, 
 netdev@vger.kernel.org, 
 linux-kernel@vger.kernel.org
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>, 
 Jakub Kicinski <kuba@kernel.org>, 
 Eric Dumazet <edumazet@google.com>, 
 Frederic Weisbecker <frederic@kernel.org>, 
 Valentin Schneider <vschneid@redhat.com>, 
 Paolo Abeni <pabeni@redhat.com>
Message-ID: <65ea00236e921_106619294ea@willemb.c.googlers.com.notmuch>
In-Reply-To: <Zen126EYArNCxIYz@tpad>
References: <Zen126EYArNCxIYz@tpad>
Subject: Re: [PATCH net-next -v5] net/core/dev.c: enable timestamp static key
 if CPU isolation is configured
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Marcelo Tosatti wrote:
> 
> For systems that use CPU isolation (via nohz_full), creating or destroying
> a socket with SO_TIMESTAMP, SO_TIMESTAMPNS or SO_TIMESTAMPING with flag
> SOF_TIMESTAMPING_RX_SOFTWARE will cause a static key to be enabled/disabled.
> This in turn causes undesired IPIs to isolated CPUs.
> 
> So enable the static key unconditionally, if CPU isolation is enabled,
> thus avoiding the IPIs.
> 
> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Reviewed-by: Willem de Bruijn <willemb@google.com>