On Wed, May 26, 2010 at 10:23:08PM +0000, Haiyang Zhang wrote: > > From: Greg KH [mailto:gregkh@xxxxxxx] > > > As discussed previously, I used atomic_t to handle more general case > > > if vmbus interrupts happen on every cpu. > > > > Ok, but then you should use a lock to protect the variable, not an > > atomic_t. > > If you care about this, because some other thread is looking at it, > > then > > you really need to protect it with a lock. Don't rely on a mb() to get > > it all correct for you (hint, I doubt it will...) > > Actually, since the interrupts only happen on cpu0, this is not a > concern. How about use a simple int variable here? Also, remove the > mb(). How about a lock! What's so scary about a pretty little semaphore? They are all cute and cuddley and don't bite anyone. You should not be afraid to use them, they are here to do your bidding. > > > The ic_channel_ready variable is called by VmbusChannelProcessOffer / > > > osd_WaitEventSet(ic_channel_ready) to wake up vmbus_init(). So it's > > > not a local variable. > > > > But again, this logic should be within the init call, as it's part of > > the proper init sequence. So just put it in that call please. > > The VmbusChannelProcessOffer() is called from interrupt context, and > initialize the channels, wake up vmbus_init when all channels are > ready. If using local variable only, how to pass the channel ready > info to vmbus_init() which is in a different context? No, I mean move the logic you added here, into the vmbus_init() call. thanks, greg k-h _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
