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Date:   Tue, 12 Dec 2023 09:22:36 -0800
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Subject: Re: [PATCH v3 13/35] KVM: x86: hyper-v: optimize and cleanup kvm_hv_process_stimers()
From:   Sean Christopherson <seanjc@google.com>
To:     Yury Norov <yury.norov@gmail.com>
Cc:     linux-kernel@vger.kernel.org,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>, kvm@vger.kernel.org,
        Jan Kara <jack@suse.cz>,
        Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>,
        Matthew Wilcox <willy@infradead.org>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Maxim Kuvyrkov <maxim.kuvyrkov@linaro.org>,
        Alexey Klimov <klimov.linux@gmail.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Sergey Shtylyov <s.shtylyov@omp.ru>
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On Mon, Dec 11, 2023, Yury Norov wrote:
> The function traverses stimer_pending_bitmap in a for-loop bit by bit.
> Simplify it by using atomic find_and_set_bit().

for_each_test_and_clear_bit(), not find_and_set_bit().

It might also be nice to call out that there are only 4 bits, i.e. that using
for_each_test_and_clear_bit() will still generate inline code.  Definitely not
mandatory though, just nice to have (I highly doubt this code would be sensitive
to using less optimal code).

> While here, refactor the logic by decreasing indentation level.
> 
> CC: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Yury Norov <yury.norov@gmail.com>
> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  arch/x86/kvm/hyperv.c | 40 ++++++++++++++++++++--------------------

This doesn't conflict with any of the in-flight Hyper-V changes, so with a fixed
changelog, feel free to take this through the bitmap tree.

Acked-by: Sean Christopherson <seanjc@google.com>