From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: Jason Xing <kerneljasonxing@gmail.com>,
Paul Menzel <pmenzel@molgen.mpg.de>
Cc: anthony.l.nguyen@intel.com, przemyslaw.kitszel@intel.com,
andrew+netdev@lunn.ch, davem@davemloft.net,
edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
bjorn@kernel.org, magnus.karlsson@intel.com,
maciej.fijalkowski@intel.com, jonathan.lemon@gmail.com,
sdf@fomichev.me, ast@kernel.org, daniel@iogearbox.net,
hawk@kernel.org, john.fastabend@gmail.com,
mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com,
linux-stm32@st-md-mailman.stormreply.com, bpf@vger.kernel.org,
intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
Jason Xing <kernelxing@tencent.com>
Subject: Re: [Intel-wired-lan] [PATCH net-next 1/2] stmmac: xsk: fix underflow of budget in zerocopy mode
Date: Tue, 22 Jul 2025 10:16:44 -0400 [thread overview]
Message-ID: <687f9d4cf0b14_2aa7cc29443@willemb.c.googlers.com.notmuch> (raw)
In-Reply-To: <CAL+tcoAP7Zk7A4pzK-za+_NMoX11SGR3ubtY6R+aaywoEq_H+g@mail.gmail.com>
Jason Xing wrote:
> Hi Paul,
>
> On Mon, Jul 21, 2025 at 4:56 PM Paul Menzel <pmenzel@molgen.mpg.de> wrote:
> >
> > Dear Jason,
> >
> >
> > Thank you for your patch.
>
> Thanks for your quick response and review :)
>
> >
> > Am 21.07.25 um 10:33 schrieb Jason Xing:
> > > From: Jason Xing <kernelxing@tencent.com>
> > >
> > > The issue can happen when the budget number of descs are consumed. As
> >
> > Instead of “The issue”, I’d use “An underflow …”.
>
> Will change it.
>
> >
> > > long as the budget is decreased to zero, it will again go into
> > > while (budget-- > 0) statement and get decreased by one, so the
> > > underflow issue can happen. It will lead to returning true whereas the
> > > expected value should be false.
> >
> > What is “it”?
>
> It means 'underflow of budget' behavior.
A technicality, but this is (negative) overflow.
Underflow is a computation that results in a value that is too small
to be represented by the given type.
next prev parent reply other threads:[~2025-07-22 14:16 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-21 8:33 [PATCH net-next 0/2] xsk: fix underflow issues in zerocopy xmit Jason Xing
2025-07-21 8:33 ` [PATCH net-next 1/2] stmmac: xsk: fix underflow of budget in zerocopy mode Jason Xing
2025-07-21 8:56 ` [Intel-wired-lan] " Paul Menzel
2025-07-21 9:15 ` Jason Xing
2025-07-22 14:16 ` Willem de Bruijn [this message]
2025-07-22 15:53 ` Jason Xing
2025-07-22 17:29 ` Willem de Bruijn
2025-07-22 23:04 ` Jason Xing
2025-07-21 15:37 ` Stanislav Fomichev
2025-07-21 23:05 ` Jason Xing
2025-07-22 0:12 ` Jason Xing
2025-07-21 8:33 ` [PATCH net-next 2/2] igb: xsk: solve underflow of nb_pkts " Jason Xing
2025-07-21 10:12 ` Simon Horman
2025-07-21 10:22 ` Jason Xing
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