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Date:   Mon, 22 Mar 2021 11:16:21 +0000
From:   Wei Liu <wei.liu@kernel.org>
To:     Michael Kelley <mikelley@microsoft.com>
Cc:     Sunil Muthuswamy <sunilmut@microsoft.com>,
        Matheus Castello <matheus@castello.eng.br>,
        "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Wei Liu <liuwe@microsoft.com>,
        Tianyu Lan <Tianyu.Lan@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, vkuznets <vkuznets@redhat.com>,
        KY Srinivasan <kys@microsoft.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4] x86/Hyper-V: Support for free page reporting
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On Fri, Mar 19, 2021 at 09:30:50PM +0000, Michael Kelley wrote:
> From: Sunil Muthuswamy <sunilmut@microsoft.com>  Sent: Friday, March 19, 2021 2:21 PM
> > 
> > > What's the strategy for this flag in the unlikely event that the hypercall fails?
> > > It doesn't seem right to have hv_query_ext_cap() fail, but leave the
> > > static flag set to true.  Just move that line down to after the status check
> > > has succeeded?
> > 
> > That call should not fail in any normal circumstances. The current idea was to
> > avoid repeating the same call on persistent failure. 
> 
> OK, I can see that as a valid strategy.  And the assumption is that a failed
> hypercall would leave hv_extended_cap unmodified and hence all zeros.
> 
> I'm OK with this approach if you want to keep it.  But perhaps add a short
> comment about the intent so it doesn't look like a bug. :-)
> 

Sunil, if you can send an updated version of your patch by either
providing a comment or moving the code around, I can queue it up for
hyperv-next.

I think adding a comment is perhaps the easier thing to do.

Wei.