Re: [PATCH v2 4/4] x86/kvm/hyper-v: avoid open-coding stimer_mark_pending() in kvm_hv_notify_acked_sint()

From: Roman Kagan <rkagan@virtuozzo.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	"Haiyang Zhang" <haiyangz@microsoft.com>,
	"Stephen Hemminger" <sthemmin@microsoft.com>,
	"x86@kernel.org" <x86@kernel.org>,
	"Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>
Subject: Re: [PATCH v2 4/4] x86/kvm/hyper-v: avoid open-coding stimer_mark_pending() in kvm_hv_notify_acked_sint()
Date: Tue, 27 Nov 2018 08:49:33 +0000	[thread overview]
Message-ID: <20181127084929.GC16047@rkaganb.sw.ru> (raw)
In-Reply-To: <20181126154732.23025-5-vkuznets@redhat.com>

On Mon, Nov 26, 2018 at 04:47:32PM +0100, Vitaly Kuznetsov wrote:
> stimers_pending optimization only helps us to avoid multiple
> kvm_make_request() calls. This doesn't happen very often and these
> calls are very cheap in the first place, remove open-coded version of
> stimer_mark_pending() from kvm_hv_notify_acked_sint().

Frankly speaking, I've yet to see a guest that configures more than one
SynIC timer.  So it was indeed a bit of overengineering in the first
place.

> Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  arch/x86/kvm/hyperv.c | 12 +++---------
>  1 file changed, 3 insertions(+), 9 deletions(-)

Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>