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SubjectRe: [PATCH] Re: Move of input drivers, some word needed from you
Hi,

> Now, currently, most of the recieve handling is postponed to the
> bottom half. I question the usefulness of this optimization. It
> certainly adds latency. What is it that needs to be done on reception
> of a few chars? Copy the data to userspace, and hit the waitq of the
> process that's waiting for data. If you want to prevent the races, use
> a kernel-space circular buffer, and do the processing (copy to
> userspace) in the context of the wokenup process.

The input line handling in n_tty.c should IMO not be done on interrupt
level. AFAIK it's the only reason put_char can't sleep and you can get the
input line handling with a simple (but admittingly not very realistic)
example to overflow, because it has to echo chars back and at some point
it simply has to drop characters.

bye, Roman

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