On Mon, Sep 28, 2020 at 02:29:34PM +0800, Shuo A Liu wrote: > On Mon 28.Sep'20 at 7:25:16 +0200, Greg Kroah-Hartman wrote: > > On Mon, Sep 28, 2020 at 11:50:30AM +0800, Shuo A Liu wrote: > > > > > + write_lock_bh(&acrn_vm_list_lock); > > > > > + list_add(&vm->list, &acrn_vm_list); > > > > > + write_unlock_bh(&acrn_vm_list_lock); > > > > > > > > Why are the _bh() variants being used here? > > > > > > > > You are only accessing this list from userspace context in this patch. > > > > > > > > Heck, you aren't even reading from the list, only writing to it... > > > > > > acrn_vm_list is read in a tasklet which dispatch I/O requests and is wrote > > > in VM creation ioctl. Use the rwlock mechanism to protect it. > > > The reading operation is introduced in the following patches of this > > > series. So i keep the lock type at the moment of introduction. > > > > Ok, but think about someone trying to review this code. Does this lock > > actually make sense here? No, it does not. How am I supposed to know > > to look at future patches to determine that it changes location and > > usage to require this? > > OK. May i know how to handle such kind of code submission? Or which way > following do you prefer? > 1) Use a mutex lock here, then change it to rwlock in a later patch > of this series.
Wouldn't this make more sense if you had to read these one after another? > 2) Add more comments in changelog about the lock. (Now, there is > comment around the acrn_vm_list_lock) It's hard to verify a comment's statement without digging through other patches in the series, right? You want the reviewer to just trust you? :) Again, what would _YOU_ want to see if you had to review this? > > That's just not fair, would you want to review something like this? > > > > And a HUGE meta-comment, again, why am I the only one reviewing this > > stuff? Why do you have a ton of Intel people on the Cc: yet it is, once > > again, my job to do this? > > The patchset has been reviewed in Intel's internal mailist several > rounds and got Reviewed-by: before send out. That's why i Cced many > Intel people as well. Then why didn't any of those intel people on the cc: actually review it after you have sent it out? Why is it only me? Do I need to wait longer for them to get to this? I'll gladly do so next time... > This patchset is all about a common driver for the ACRN hypervisor > support. I put the code in drivers/virt/ and found you are one of the > maintainer of vboxguest driver which is in the same subdirectory. I > thought you should be the right person to be Cced when i submitted this > series. I am, I'm not complaining about that. I'm complaining that it seems to be _only_ me reviewing this here, and not any of the people you are cc:ing from intel. Most of those people should be giving you this same type of review comments and not forcing an external person to do so, right? > Certainly, any comments are welcome. And really appreciate your review > and help. I have little experience to submit a new driver to the > community, my apologies if thing goes wrong. You didn't do anything wrong, I'm arguing about the larger meta-issue I have right now with Intel and the lack of reviews that seems to happen from other Intel people on their co-workers patches. Anyway, you are doing fine, it's an iterative process, hopefully you can also review other people's patches in this area that are being posted as well. thanks, greg k-h
