From: Joel Fernandes <joelaf@google.com>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Marc Zyngier <maz@kernel.org>, yezengruan <yezengruan@huawei.com>,
Will Deacon <will@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Suleiman Souhlal <suleiman@google.com>,
kvmarm@lists.cs.columbia.edu,
"moderated list:ARM64 PORT (AARCH64 ARCHITECTURE)"
<linux-arm-kernel@lists.infradead.org>,
"Wanghaibin (D)" <wanghaibin.wang@huawei.com>,
Quentin Perret <qperret@google.com>
Subject: Re: [RFC][PATCH 0/4] arm64:kvm: teach guest sched that VCPUs can be preempted
Date: Tue, 8 Dec 2020 15:02:47 -0500 [thread overview]
Message-ID: <CAJWu+oq26OK1-7Ze2pb5xpRJ-tS9wtXOdGFrYpHq+fhkyGhjkA@mail.gmail.com> (raw)
In-Reply-To: <20200911085841.GB562@jagdpanzerIV.localdomain>
On Fri, Sep 11, 2020 at 4:58 AM Sergey Senozhatsky
<sergey.senozhatsky@gmail.com> wrote:
>
> My apologies for the slow reply.
>
> On (20/08/17 13:25), Marc Zyngier wrote:
> >
> > It really isn't the same thing at all. You are exposing PV spinlocks,
> > while Sergey exposes preemption to vcpus.
> >
>
> Correct, we see vcpu preemption as a "fundamental" feature, with
> consequences that affect scheduling, which is a core feature :)
>
> Marc, is there anything in particular that you dislike about this RFC
> patch set? Joel has some ideas, which we may discuss offline if that
> works for you.
Hi Marc, Sergey, Just checking what is the latest on this series?
About the idea me and Sergey discussed, at a high level we discussed
being able to share information similar to "Is the vCPU preempted?"
using a more arch-independent infrastructure. I do not believe this
needs to be arch-specific. Maybe the speciifc mechanism about how to
share a page of information needs to be arch-specific, but the actual
information shared need not be. This could open the door to sharing
more such information in an arch-independent way (for example, if the
scheduler needs to know other information such as the capacity of the
CPU that the vCPU is on).
Other thoughts?
thanks,
- Joel
next prev parent reply other threads:[~2020-12-08 20:32 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 4:17 [RFC][PATCH 0/4] arm64:kvm: teach guest sched that VCPUs can be preempted Sergey Senozhatsky
2020-07-21 4:17 ` [RFC][PATCH 1/4] arm64:kvm: define pv_state SMCCC HV calls Sergey Senozhatsky
2020-07-21 4:17 ` [RFC][PATCH 2/4] arm64: add guest pvstate support Sergey Senozhatsky
2020-07-21 4:17 ` [RFC][PATCH 3/4] arm64: add host " Sergey Senozhatsky
2020-07-21 4:17 ` [RFC][PATCH 4/4] arm64: do not use dummy vcpu_is_preempted() anymore Sergey Senozhatsky
2020-08-17 2:03 ` [RFC][PATCH 0/4] arm64:kvm: teach guest sched that VCPUs can be preempted Sergey Senozhatsky
2020-08-17 12:03 ` yezengruan
2020-08-17 12:25 ` Marc Zyngier
2020-08-17 14:15 ` yezengruan
2020-09-11 8:58 ` Sergey Senozhatsky
2020-12-08 20:02 ` Joel Fernandes [this message]
2020-12-09 9:43 ` Marc Zyngier
2020-12-10 1:39 ` Joel Fernandes
2020-12-10 8:45 ` Marc Zyngier
2020-12-11 9:34 ` Quentin Perret
2020-12-16 1:45 ` Joel Fernandes
2020-09-11 8:46 ` Sergey Senozhatsky
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