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SubjectRe: [PATCH 3/3] Convert the UDP hash lock to RCU
Eric Dumazet wrote:

> 1) Hum, do you know why "struct file" objects dont use
> since we noticed a performance regression for several workloads at
> RCUification
> of file structures ?

Because my patches were not accepted that fix the issue.

> 2) What prevents an object to be *freed* (and deleted from a hash
> chain), then
> re-allocated and inserted to another chain (different keys) ? (final
> refcount=1)


> If the lookup detects a key mismatch, how will it continue to the next
> item,
> since 'next' pointer will have been reused for the new chain insertion...
> Me confused...

If there is a mismatch then you have to do another hash lookup. Do an rcu
unlock and start over.

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