> From: Stephen Hemminger [mailto:stephen@xxxxxxxxxxxxxxxxxx] > Sent: Wednesday, January 25, 2017 00:08 > To: Dexuan Cui <decui@xxxxxxxxxxxxx> > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx; KY > Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; > Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>; olaf@xxxxxxxxx; Rolf > Neugebauer <rolf.neugebauer@xxxxxxxxxx>; jasowang@xxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; apw@xxxxxxxxxxxxx > Subject: Re: [PATCH] Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read() > > On Tue, 24 Jan 2017 06:54:46 +0000 > Dexuan Cui <decui@xxxxxxxxxxxxx> wrote: > > > +static inline void > > +init_cached_read_index(struct vmbus_channel *channel) > > +{ > > + struct hv_ring_buffer_info *rbi = &channel->inbound; > > + > > + rbi->cached_read_index = rbi->ring_buffer->read_index; > > +} > > Looks good thanks. This should go in right away. Which versions are impacted? > Should it also go to stable? Yes, it needs to go to stable. I have Cc-ed <stable@xxxxxxxxxxxxxxx> in the patch's changelog, so it should be included in the stable tree automatically. As I checked against the kernels listed on the homapage of www.kernel.org, the below versions are impacted: v3.16.39 v3.18.47 v4.1.38 v4.8.17 v4.9.5 v4.10-rc5 It's interesting v4.4.44 is not impacted, but actually it needs both the 2 patches: i.e. this patch, and the previous one: Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") > In a future patch, the API function names for interacting with the ring buffer > should be changed to all have common prefix (hv_) and maybe do a little > rethinking about what needs to be in ring buffer and what could be local variables. > > For example, the cached_read_index is only useful over the span of the loop > reading from the ring buffer. For me, it would be cleaner with a ring_buffer > iterator object which could abstract the API better. > > struct vmbus_ringbuffer_iter iter; > > vmbus_begin_read(&iter, channel); > while ((desc = vmbus_next_read(&iter), channel) { > ... > } > vmbus_end_read(&iter, channel); I agree. Please help to clean all these up. :-) Thanks, -- Dexuan _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
