netdev - Re: [PATCH v20 net-next 1/6] sched: Struct definition and parsing of dualpi2 qdisc

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Message-ID: <20250630092316.031b29d8@kernel.org>
Date: Mon, 30 Jun 2025 09:23:16 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: "Chia-Yu Chang (Nokia)" <chia-yu.chang@...ia-bell-labs.com>
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Subject: Re: [PATCH v20 net-next 1/6] sched: Struct definition and parsing
 of dualpi2 qdisc

On Mon, 30 Jun 2025 15:51:11 +0000 Chia-Yu Chang (Nokia) wrote:
> > > Thanks again for other comments again, and I will take actions in the next version.
> > >
> > > As there is only one step marking in L-queue, so we still need two 
> > > WRITE_ONCE even two attributes (one for threshold in packets and one 
> > > in time) are used.
> > >
> > > When applying the step marking, we need to know either the computation 
> > > is based on the sojourn time or queue length.  
> > 
> > Let me ask again - why do you use WRITE_ONCE() at all if the
> > modification takes the qdisc lock? Which reader are you afraid of
> > racing with?  
> 
> This still needs 2 WRITE_ONCE even "step_thresh" (NLA_U32) and
> "step_in_packtes" (NLA_FLAG) are replaced with "step_pkt_thresh"
> (NLA_U32) and "step_time_thresh" (NLA_U32) - which was proposed in my
> another email.

If you don't understand the question - ask for clarifications :/