Re: [Qemu-devel] [RFC] [PATCHv8 00/30] aio / timers: Add AioContext timers and use ppoll

[Paolo Bonzini]

Il 08/08/2013 23:41, Alex Bligh ha scritto:
> This patch series adds support for timers attached to an AioContext clock
> which get called within aio_poll.
> 
> In doing so it removes alarm timers and moves to use ppoll where possible.
> 
> This patch set 'sort of' passes make check (see below for caveat)
> including a new test harness for the aio timers, but has not been
> tested much beyond that. In particular, the win32 changes have not
> even been compile tested. Equally, alterations to use_icount
> are untested.
> 
> Caveat: I have had to alter tests/test-aio.c so the following error
> no longer occurs.
> 
> ERROR:tests/test-aio.c:346:test_wait_event_notifier_noflush: assertion 
> failed: (aio_poll(ctx, false))
> 
> As gar as I can tell, this check was incorrect, in that it checking
> aio_poll makes progress when in fact it should not make progress. I
> fixed an issue where aio_poll was (as far as I can tell) wrongly
> returning true on a timeout, and that generated this error.
> 
> Note also the comment on patch 18 in relation to a possible bug
> in cpus.c.
> 
> The penultimate patch is patch which is created in an automated manner
> using scripts/switch-timer-api, added in this patch set. It violates some
> coding standards (e.g. line length >= 80 characters), but this is preferable
> in terms of giving a provably correct conversion.
> 
> This patch set has been compile tested & make check tested on a
> 'christmas-tree' configuration, meaning a configuration with every
> --enable- value tested that can be easily configured on Ubuntu Precise,
> after application of each patch.

Awesome work, really.  I think we can still simplify it a bit, but many
of the changes I asked should be doable with a global search-and-replace
on the patch files.

Thanks!

Paolo