Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue

[Peter Maydell]

On 10 November 2015 at 14:25, Juan Quintela <address@hidden> wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
>
> When transmitting RAM pages, consume pages that have been queued by
> MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.
>
> Note:
>   a) After a queued page the linear walk carries on from after the
> unqueued page; there is a reasonable chance that the destination
> was about to ask for other closeby pages anyway.
>
>   b) We have to be careful of any assumptions that the page walking
> code makes, in particular it does some short cuts on its first linear
> walk that break as soon as we do a queued page.
>
>   c) We have to be careful to not break up host-page size chunks, since
> this makes it harder to place the pages on the destination.
>
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> Reviewed-by: Juan Quintela <address@hidden>
> Signed-off-by: Juan Quintela <address@hidden>

I've just discovered that this is causing 'make check' failures on
my OSX host (unfortunately something in my setup is causing
'make check' failures to not always cause a build failure, so I
didn't notice earlier):

manooth$ (make -C build/x86 -j8 && cd build/x86 &&
QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64
QTEST_QEMU_IMG=qemu-img MALLOC_PERTURB_=${MALLOC_PERTURB_:-$((RANDOM %
255 + 1))}  tests/ahci-test)
[...]

/x86_64/ahci/flush/simple: OK
/x86_64/ahci/flush/retry: OK
/x86_64/ahci/flush/migrate: qemu: qemu_mutex_lock: Invalid argument
qemu-system-x86_64:Broken pipe
 Not a migration stream
qemu-system-x86_64: load of migration failed: Invalid argument

thanks
-- PMM