Re: [PATCH net-next 2/5] netdev-genl: Dump napi_defer_hard_irqs
From: Jakub Kicinski <kuba@kernel.org>
Date: 2024-08-29 22:08:30
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On Thu, 29 Aug 2024 13:11:58 +0000 Joe Damato wrote:
quoted hunk ↗ jump to hunk
diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml index 959755be4d7f..ee4f99fd4574 100644 --- a/Documentation/netlink/specs/netdev.yaml +++ b/Documentation/netlink/specs/netdev.yaml@@ -244,6 +244,11 @@ attribute-sets: threaded mode. If NAPI is not in threaded mode (i.e. uses normal softirq context), the attribute will be absent. type: u32 + - + name: defer-hard-irqs + doc: The number of consecutive empty polls before IRQ deferral ends + and hardware IRQs are re-enabled. + type: s32
Why is this a signed value? 🤔️ You can use: check: max: s32-max to have netlink validate the overflow if you switch to u32.
-
name: queue
attributes:quoted hunk ↗ jump to hunk
@@ -188,6 +189,10 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi, goto nla_put_failure; } + napi_defer_hard_irqs = napi_get_defer_hard_irqs(napi);
Here, for example the READ_ONCE() wouldn't have been necessary, right? Cause we are holding rtnl_lock(), just a random thought, not really actionable.
+ if (nla_put_s32(rsp, NETDEV_A_NAPI_DEFER_HARD_IRQS, napi_defer_hard_irqs)) + goto nla_put_failure;