Messages in this thread | | | Subject | Re: linux-next: manual merge of the staging tree with the target-merge tree | From | "Nicholas A. Bellinger" <> | Date | Sun, 22 Jul 2012 14:44:23 -0700 |
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On Sat, 2012-07-21 at 19:07 -0700, Greg KH wrote: > On Fri, Jul 20, 2012 at 09:42:28PM +0300, Michael S. Tsirkin wrote:
<SNIP>
> > It's very similar to how it was with nouveau: we are not sure > > we can commit to the userspace ABI yet. > > Then you are in trouble :) >
I agree with MST here that tcm_vhost needs a clear way to indicate that ABI changes are likely to occur in transmit from staging -> post-staging status.
> > Most importantly, it still seems not 100% clear whether this driver will > > have major userspace using it. And if not, it would be very hard to > > support a driver when recent userspace does not use it in the end. > > > > At the moment arguments on upstream mailing list seem to be > > a bit circular: there's no module in upstream kernel so > > userspace does not want to accept the patches. > > > > If we put enabling this driver in staging, then it works out in one of > > two ways > > - userspace starts using it then this effectively freezes the ABI and > > we move it out of staging next release > > - no userspace uses it and we drop it completely or rework ABI > > > > On the other hand, it is marginally better to not want code in staging > > for two reasons: > > - there are dependencies between this code and other code in > > drivers/vhost which are easier for me to handle if it's all > > in one place > > If there are going to be lots of dependancies, then I don't want it in > drivers/staging/ as it doesn't belong there, it belongs cleaned up and > in the "real" place. > > > - a bit easier to track history if we do not move code > > git preserves this, don't worry about that at all. > > So, if this code really does depend on core vhost changes that are going > to be happening over time, I would not recommend it being in > drivers/staging/ as you are right, you are going to have a hard time > syncing with me. >
So Linus has merged target-pending/for-next this afternoon, so now we are just waiting on net-next to hit mainline with the vhost patches already ACK'ed by MST. Hopefully that makes things easier for you to considering taking tcm_vhost upstream via staging. ;)
Also, MST asked for an RFC-v5 for the initial merge commit with some minor debug wrapper changes that will be going out next week. This will include a move into drivers/staging/tcm_vhost/ against a rebased staging.git patch with the necessary -rc0 mainline dependencies.
Please let me know if your OK with this, otherwise I'll just plan to keep -v5 against target-pending/for-next-merge for now, and send a GIT PULL after MST gets back from holiday on the 29th -> 30th.
> But don't think that by somehow marking the driver with CONFIG_STAGING > that you get a free pass on the "we are going to break the userspace > api", that's not ok. Be careful about this. Yes, it's tough, and it's > a "chicken and egg" problem like you mention above, I know. >
After sleeping on this, I'm wondering if there is not something else we could do at the QEMU level to require an explicit 'development=1' flag in order to use vhost-scsi while tcm_vhost is still marked as staging code..?
QEMU folks, would you be open to something like this..?
Thank you,
--nab
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