On Mon, 29 Apr 2024 10:47:41 -0700, Jakub Kicinski <kuba@xxxxxxxxxx> wrote: > On Sun, 28 Apr 2024 22:49:09 +0800 Heng Qi wrote: > > >> + 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. So here we can use: + if (moder[ETHTOOL_A_IRQ_MODERATION_USEC]) { + if (irq_moder->coal_flags & DIM_COALESCE_USEC) + new_profile[i].usec = + nla_get_u32(moder[ETHTOOL_A_IRQ_MODERATION_USEC]); + else + return -EOPNOTSUPP; + } instead of: + if (!NL_REQ_ATTR_CHECK(extack, nest, moder, ETHTOOL_A_IRQ_MODERATION_USEC)) { + if (irq_moder->coal_flags & DIM_COALESCE_USEC) + new_profile[i].usec = + nla_get_u32(moder[ETHTOOL_A_IRQ_MODERATION_USEC]); + else + return -EOPNOTSUPP; + } to avoid missing information set in extack? Thanks.