Re: [Qemu-devel] [PATCH 3/3] Add helper functions for virtio-9p to use threadlets

[Anthony Liguori <anthony@codemonkey.ws>]

On 10/20/2010 06:19 AM, Stefan Hajnoczi wrote:
> On Tue, Oct 19, 2010 at 6:43 PM, Arun R Bharadwaj
> <arun@linux.vnet.ibm.com>  wrote:
>    
>> From: Gautham R Shenoy<ego@in.ibm.com>
>>
>> Add helper functions to enable virtio-9p make use of the threadlets
>> infrastructure for offloading blocking tasks such as making posix calls on
>> to the helper threads and handle the post_posix_operations() from the
>> context of the iothread. This frees the vcpu thread to process any other guest
>> operations while the processing of v9fs_io is in progress.
>>
>> Signed-off-by: Gautham R Shenoy<ego@in.ibm.com>
>> Signed-off-by: Sripathi Kodi<sripathik@in.ibm.com>
>> Signed-off-by: Arun R Bharadwaj<arun@linux.vnet.ibm.com>
>> ---
>>   hw/virtio-9p.c     |  165 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   posix-aio-compat.c |   33 +++-------
>>   qemu-threadlets.c  |   21 +++++++
>>   qemu-threadlets.h  |    1
>>   vl.c               |    3 +
>>   5 files changed, 200 insertions(+), 23 deletions(-)
>>      
> I wish --enable-io-thread was the default and only model.  The signals
> and pipes are ugly and should be hidden behind a QEMU eventfd
> abstraction, which would also reduce the code duplication between
> posix-aio-compat.c and virtio-9p.  I'm not asking you to do this but I
> hope we'll get there eventually.
>
> Does anyone know why non-io-thread still exists and is used by default?
>    

There are still issues with --enable-io-thread and TCG.

Regards,

Anthony Liguori