From: Jakub Kicinski <kuba@kernel•org>
To: Heng Qi <hengqi@linux•alibaba.com>
Cc: netdev@vger•kernel.org, virtualization@lists•linux.dev,
"David S . Miller" <davem@davemloft•net>,
Paolo Abeni <pabeni@redhat•com>,
Eric Dumazet <edumazet@google•com>,
Jason Wang <jasowang@redhat•com>,
"Michael S . Tsirkin" <mst@redhat•com>,
Brett Creeley <bcreeley@amd•com>,
Ratheesh Kannoth <rkannoth@marvell•com>,
Alexander Lobakin <aleksander.lobakin@intel•com>,
Xuan Zhuo <xuanzhuo@linux•alibaba.com>,
Tal Gilboa <talgi@nvidia•com>, Jonathan Corbet <corbet@lwn•net>,
linux-doc@vger•kernel.org,
Maxime Chevallier <maxime.chevallier@bootlin•com>,
Jiri Pirko <jiri@resnulli•us>,
Paul Greenwalt <paul.greenwalt@intel•com>,
Ahmed Zaki <ahmed.zaki@intel•com>,
Vladimir Oltean <vladimir.oltean@nxp•com>,
Kory Maincent <kory.maincent@bootlin•com>,
Andrew Lunn <andrew@lunn•ch>,
"justinstitt @ google . com" <justinstitt@google•com>
Subject: Re: [PATCH net-next v10 2/4] ethtool: provide customized dim profile management
Date: Mon, 29 Apr 2024 10:47:41 -0700 [thread overview]
Message-ID: <20240429104741.3a628fe6@kernel.org> (raw)
In-Reply-To: <98ea9d4d-1a90-45b9-a4e0-6941969295be@linux.alibaba.com>
On Sun, 28 Apr 2024 22:49:09 +0800 Heng Qi wrote:
> >> +#if IS_ENABLED(CONFIG_DIMLIB)
> >> + if (dev->irq_moder) {
> > This may be NULL
>
>
> Do you mean dev may be null or dev->irq_moder may be null?
> The former has been excluded (see const struct ethtool_ops *ops
>
> = req_info->dev->ethtool_ops;).
>
> And we are ruling out the latter using 'if (dev->irq_moder)'.
>
> Or something else?
Hm, I must have misread something here.
> >> + nla_for_each_nested_type(nest, ETHTOOL_A_PROFILE_IRQ_MODERATION, nests, rem) {
> >> + ret = nla_parse_nested(moder,
> >> + ARRAY_SIZE(coalesce_irq_moderation_policy) - 1,
> >> + nest, coalesce_irq_moderation_policy,
> >> + extack);
> >> + if (ret)
> >> + return ret;
> >> +
> >> + if (!NL_REQ_ATTR_CHECK(extack, nest, moder, ETHTOOL_A_IRQ_MODERATION_USEC)) {
> >> + if (irq_moder->coal_flags & DIM_COALESCE_USEC)
> > There are 3 options here, not 2:
> >
> > if (irq_moder->coal_flags & flag) {
> > if (NL_REQ_ATTR_CHECK())
> > val = nla_get_u32(...);
> > else
> > return -EINVAL;
> > } else {
> > if (moder[attr_type)) {
> > BAD_ATTR()
> > return -EOPNOTSUPP;
> > }
> > }
>
> Maybe we missed something.
>
> As shown in the commit log, the user is allowed to modify only
> a certain fields in irq-moderation. It is assumed that the driver
> supports modification of usec and pkts, but the user may only
> modify usec and only fill in the usec attr.
>
> Therefore, the kernel only gets usec attr here. Of course, the user
> may have passed in 5 groups of "n, n, n", which means that nothing
> is modified, and rx_profile and irq_moderation attrs are all empty.
What you describe sounds good, but it's not what the code seems to be
doing. NL_REQ_ATTR_CHECK() will set an error attribute if the attr is
not present.
next prev parent reply other threads:[~2024-04-29 17:47 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-25 16:59 [PATCH net-next v10 0/4] ethtool: provide the dim profile fine-tuning channel Heng Qi
2024-04-25 16:59 ` [PATCH net-next v10 1/4] linux/dim: move useful macros to .h file Heng Qi
2024-04-25 16:59 ` [PATCH net-next v10 2/4] ethtool: provide customized dim profile management Heng Qi
2024-04-27 1:33 ` Jakub Kicinski
2024-04-28 14:49 ` Heng Qi
2024-04-29 17:47 ` Jakub Kicinski [this message]
2024-04-30 1:59 ` Heng Qi
2024-04-30 3:13 ` Jakub Kicinski
2024-04-30 4:43 ` Heng Qi
2024-04-25 16:59 ` [PATCH net-next v10 3/4] dim: add new interfaces for initialization and getting results Heng Qi
2024-04-25 16:59 ` [PATCH net-next v10 4/4] virtio-net: support dim profile fine-tuning Heng Qi
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