Re: [take13 0/3] kevent: Generic event handling mechanism.

From: Evgeniy Polyakov
Date: Wed Aug 23 2006 - 15:41:18 EST


On Wed, Aug 23, 2006 at 10:56:24PM +0400, Evgeniy Polyakov (johnpol@xxxxxxxxxxx) wrote:
> > It can be done by selecting special event type, which in turn will reuse
> > special fields as length.
> > But variable-sized members can not be put into cache and without
> > knowledge of it's size it is impossible to put htem into mapped buffer.
>
> And thinking more about this issue, I can say that I'm again
> variable-sized structures - they can not be placed into ring buffer (at
> least into simple one), they do not allow allocation from cache, it is
> impossible to get them correctly from userspace if there is now exact
> knowledge about nature of that events and a lot of other problems.
> If one strongly feels that it is required, it is possible to provide
> userspace pointer in the ukevent structure, which then can be read in
> ->enqueue callback by kernelside (there is similar trick in network
> AIO).

I've reread my text - sorry for tons of errors, I use extremely slow
GPRS link, so it is almost impossible to return and correct errors using
it, I think it is simple to understand what I meant :)

--
Evgeniy Polyakov
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