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From:   Mingwei Zhang <mizhang@google.com>
Date:   Thu, 30 Jun 2022 14:00:27 -0700
Message-ID: <CAL715W+9U=5rp3+j3wG46t0Uvq-UAOFduC-AXz-Z9ZJVQXDzDg@mail.gmail.com>
Subject: Re: [PATCH v3 02/11] KVM: selftests: Dump VM stats in binary stats test
To:     Sean Christopherson <seanjc@google.com>
Cc:     Ben Gardon <bgardon@google.com>,
        LKML <linux-kernel@vger.kernel.org>, kvm <kvm@vger.kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Peter Xu <peterx@redhat.com>,
        David Matlack <dmatlack@google.com>,
        Jim Mattson <jmattson@google.com>,
        David Dunn <daviddunn@google.com>,
        Jing Zhang <jingzhangos@google.com>,
        Junaid Shahid <junaids@google.com>
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On Fri, Apr 8, 2022 at 12:52 PM Sean Christopherson <seanjc@google.com> wrote:
>
> On Wed, Mar 30, 2022, Ben Gardon wrote:
> > Add kvm_util library functions to read KVM stats through the binary
> > stats interface and then dump them to stdout when running the binary
> > stats test. Subsequent commits will extend the kvm_util code and use it
> > to make assertions in a test for NX hugepages.
>
> Why?  Spamming my console with info that has zero meaning to me and is useless
> when the test passes is not helpful.  Even on failure, I don't see what the user
> is going to do with this information, all of the asserts are completly unrelated
> to the stats themselves.

Debugging could be another reason, I suspect? I remember when I tried
to use the interface, there is really no API that tells me "did I add
this stat successfully and/or correctly?" I think having a general
print so that developer/debugging folk could just 'grep mystat' to
verify that would be helpful in the future.

Otherwise, they have to write code themselves to do the dirty print...