Re: Collapsing RT signals ...

From: Davide Libenzi (
Date: Mon Jun 25 2001 - 10:43:30 EST

On 25-Jun-2001 Dan Kegel wrote:
> Davide Libenzi <> wrote:
>> I'm making some test with RT signals and looking at how they're implemented
>> inside the kernel.
>> After having experienced frequent queue overflow signals I looked at how
>> signals are queued inside the task_struct.
>> There's no signals optimization inside and this make the queue length
>> depending
>> on the request rate instead of the number of connections.
>> It can happen that two ( or more ) POLL_IN signals are queued with a single
>> read() that sweep the buffer leaving other signals to issue reads ( read
>> this
>> as user-mode / kernel-mode switch ) that will fail due lack of data.
>> So for every "superfluous" signal we'll have two user-mode / kernel-mode
>> switches, one for signal delivery and one for a failing read().
>> I'm just thinking at a way to optimize the signal delivery that is ( draft )
>> :
>> ...
> I agree, the queue overflow case is a pain in the butt.
> Before you get too far coding up your idea, have you read

Double thank You Dan, they did exactly what I want to do :)

- Davide

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This archive was generated by hypermail 2b29 : Sat Jun 30 2001 - 21:00:12 EST