From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Alexander Graf <agraf@suse.de>
Cc: "Scott Wood" <scottwood@freescale.com>,
kvm-ppc@vger.kernel.org, "Jörg Sommer" <joerg@alea.gnuu.de>,
"KVM list" <kvm@vger.kernel.org>
Subject: Re: [PATCH 4/4] KVM: PPC: align vcpu_kick with x86
Date: Sat, 24 Dec 2011 08:50:11 +1100 [thread overview]
Message-ID: <1324677011.6632.15.camel@pasglop> (raw)
In-Reply-To: <E9B7009D-24F8-497A-AE56-EB0472C167DA@suse.de>
On Fri, 2011-12-23 at 13:56 +0100, Alexander Graf wrote:
> > Hmm, unless smp_send_reschedule must be called with preemption disabled
> > (doesn't seem like an obvious requirement, even if callers commonly have
> > a reason to do so, and the only documentation of it I see is on the ia64
> > implementation), that seems like a bug in the MPIC IPI implementation.
> >
> > It wouldn't be an issue (and would make the MPIC driver slightly faster,
> > too) if the MPIC driver were to use the magic CPU region instead of
> > manually indexing the non-magic array of per-CPU regions. Maybe it
> > doesn't work on all hardware the driver supports?
Right, the magic per-cpu region doesn't work on all HW.
> I'd say that's a question I'll redirect to Ben :).
>
> > Not that it matters much here -- we want this patch anyway, because we
> > want to check that it's not the current CPU.
>
> Yeah. Well - eventually we want the exact same vcpu_kick function across architectures.
> But this is a good step in the right direction.
Cheers,
Ben.
prev parent reply other threads:[~2011-12-23 21:50 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-09 15:26 [PATCH 0/4] Fix book3s-pr KVM with preemption Alexander Graf
2011-12-09 15:26 ` [PATCH 1/4] KVM: PPC: Book3s: PR: Disable preemption in vcpu_run Alexander Graf
2011-12-09 18:19 ` Scott Wood
2011-12-09 23:18 ` Alexander Graf
2011-12-13 21:15 ` Scott Wood
2011-12-09 15:26 ` [PATCH 2/4] KVM: PPC: Book3s: PR: No irq_disable " Alexander Graf
2011-12-09 15:26 ` [PATCH 3/4] KVM: PPC: Use get/set for to_svcpu to help preemption Alexander Graf
2011-12-09 15:26 ` [PATCH 4/4] KVM: PPC: align vcpu_kick with x86 Alexander Graf
2011-12-09 18:19 ` Scott Wood
2011-12-09 19:10 ` Alexander Graf
2011-12-09 19:15 ` Scott Wood
2011-12-09 23:15 ` Alexander Graf
2011-12-12 17:32 ` Scott Wood
2011-12-23 12:56 ` Alexander Graf
2011-12-23 21:50 ` Benjamin Herrenschmidt [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1324677011.6632.15.camel@pasglop \
--to=benh@kernel.crashing.org \
--cc=agraf@suse.de \
--cc=joerg@alea.gnuu.de \
--cc=kvm-ppc@vger.kernel.org \
--cc=kvm@vger.kernel.org \
--cc=scottwood@freescale.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).