From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Shuo A Liu <shuo.a.liu@intel.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
"H . Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Yu Wang <yu1.wang@intel.com>,
Reinette Chatre <reinette.chatre@intel.com>,
Zhi Wang <zhi.a.wang@intel.com>,
Zhenyu Wang <zhenyuw@linux.intel.com>
Subject: Re: [PATCH v4 06/17] virt: acrn: Introduce VM management interfaces
Date: Mon, 28 Sep 2020 14:26:02 +0200 [thread overview]
Message-ID: <20200928122602.GB682772@kroah.com> (raw)
In-Reply-To: <20200928062934.GF1057@shuo-intel.sh.intel.com>
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
next prev parent reply other threads:[~2020-09-28 12:25 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 11:42 [PATCH v4 00/17] HSM driver for ACRN hypervisor shuo.a.liu
2020-09-22 11:42 ` [PATCH v4 01/17] docs: acrn: Introduce ACRN shuo.a.liu
2020-10-09 1:48 ` Randy Dunlap
2020-10-12 8:50 ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 02/17] x86/acrn: Introduce acrn_{setup, remove}_intr_handler() shuo.a.liu
2020-09-27 10:49 ` Greg Kroah-Hartman
2020-09-28 3:28 ` Shuo A Liu
2020-09-29 18:01 ` Borislav Petkov
2020-09-29 20:07 ` Thomas Gleixner
2020-09-29 20:26 ` Borislav Petkov
2020-09-30 3:02 ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 03/17] x86/acrn: Introduce an API to check if a VM is privileged shuo.a.liu
2020-09-30 8:09 ` Borislav Petkov
2020-10-12 8:40 ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 04/17] x86/acrn: Introduce hypercall interfaces shuo.a.liu
2020-09-27 10:51 ` Greg Kroah-Hartman
2020-09-27 10:53 ` Greg Kroah-Hartman
2020-09-28 3:38 ` Shuo A Liu
2020-09-27 15:38 ` Dave Hansen
2020-09-30 11:16 ` Peter Zijlstra
2020-09-30 16:10 ` Segher Boessenkool
2020-09-30 17:13 ` Peter Zijlstra
2020-09-30 19:14 ` Nick Desaulniers
2020-09-30 19:42 ` Peter Zijlstra
2020-09-30 23:58 ` Segher Boessenkool
2020-09-30 19:59 ` Arvind Sankar
2020-09-30 20:01 ` Arvind Sankar
2020-10-01 0:08 ` Segher Boessenkool
2020-09-30 23:25 ` Segher Boessenkool
2020-09-30 23:38 ` Arvind Sankar
2020-10-01 0:11 ` Segher Boessenkool
2020-10-12 8:44 ` Shuo A Liu
2020-10-12 16:49 ` Arvind Sankar
2020-10-13 2:44 ` Shuo A Liu
2020-09-30 10:54 ` Borislav Petkov
2020-10-12 8:49 ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 05/17] virt: acrn: Introduce ACRN HSM basic driver shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 08/17] virt: acrn: Introduce EPT mapping management shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 10/17] virt: acrn: Introduce PCI configuration space PIO accesses combiner shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 11/17] virt: acrn: Introduce interfaces for PCI device passthrough shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 12/17] virt: acrn: Introduce interrupt injection interfaces shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 14/17] virt: acrn: Introduce I/O ranges operation interfaces shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 16/17] virt: acrn: Introduce irqfd shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 17/17] virt: acrn: Introduce an interface for Service VM to control vCPU shuo.a.liu
2020-09-27 10:44 ` Greg Kroah-Hartman
2020-09-28 4:10 ` Shuo A Liu
2020-09-28 5:23 ` Greg Kroah-Hartman
2020-09-28 6:33 ` Shuo A Liu
2020-09-27 0:24 ` [PATCH v4 00/17] HSM driver for ACRN hypervisor Liu, Shuo A
2020-09-27 5:42 ` Greg Kroah-Hartman
[not found] ` <20200922114311.38804-7-shuo.a.liu@intel.com>
2020-09-27 10:45 ` [PATCH v4 06/17] virt: acrn: Introduce VM management interfaces Greg Kroah-Hartman
2020-09-28 3:43 ` Shuo A Liu
2020-09-27 10:47 ` Greg Kroah-Hartman
2020-09-28 3:50 ` Shuo A Liu
2020-09-28 5:25 ` Greg Kroah-Hartman
2020-09-28 6:29 ` Shuo A Liu
2020-09-28 12:26 ` Greg Kroah-Hartman [this message]
2020-09-30 2:49 ` Shuo A Liu
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