Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8;
Date:   Tue, 12 Dec 2023 09:35:59 -0800
From:   Yury Norov <yury.norov@gmail.com>
To:     Sean Christopherson <seanjc@google.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>
Subject: Re: [PATCH v3 13/35] KVM: x86: hyper-v: optimize and cleanup
 kvm_hv_process_stimers()
Message-ID: <ZXiZ9XviH84mXPG5@yury-ThinkPad>
References: <20231212022749.625238-1-yury.norov@gmail.com>
 <20231212022749.625238-14-yury.norov@gmail.com>
 <ZXiW3AgIENf7whei@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ZXiW3AgIENf7whei@google.com>
Precedence: bulk

On Tue, Dec 12, 2023 at 09:22:36AM -0800, Sean Christopherson wrote:
> 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).

Sure, will do.
 
> > 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>

Thank you!