From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org,
kvm-ppc@vger.kernel.org
Subject: Re: [PATCH 24/30] KVM: PPC: booke: call resched after every exit
Date: Mon, 20 Feb 2012 11:18:41 -0600 [thread overview]
Message-ID: <4F428071.6000304@freescale.com> (raw)
In-Reply-To: <4B831F36-4BEB-4BDF-869D-117617B4EE44@suse.de>
On 02/20/2012 07:17 AM, Alexander Graf wrote:
>
> On 18.02.2012, at 00:00, Scott Wood wrote:
>
>> It would be simpler (both here and in the idle hcall) if we could just
>> drop support for CONFIG_PREEMPT=n. :-P
>
> When running with CONFIG_PREEMPT=n we don't have to worry about interrupts being enabled though,
That's exactly when we *do* need to worry. Interrupts can cause the
"need resched" condition to become true.
> since we only preempt on known good checkpoints, right?
Yes, and "entering the guest" is supposed to be one of those known good
checkpoints, similar to returning to userspace. If we miss a reschedule
here, we're may not have another chance until the next timer interrupt.
The code for returning to userspace is similarly structured.
-Scott
next prev parent reply other threads:[~2012-02-20 17:19 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-17 17:13 [PATCH 00/30] KVM: PPC: e500mc support Alexander Graf
2012-02-17 17:13 ` [PATCH 01/30] powerpc/booke: Set CPU_FTR_DEBUG_LVL_EXC on 32-bit Alexander Graf
2012-02-17 17:13 ` [PATCH 02/30] powerpc/e500: split CPU_FTRS_ALWAYS/CPU_FTRS_POSSIBLE Alexander Graf
2012-02-17 17:13 ` [PATCH 03/30] KVM: PPC: factor out lpid allocator from book3s_64_mmu_hv Alexander Graf
2012-02-17 17:13 ` [PATCH 04/30] KVM: PPC: booke: add booke-level vcpu load/put Alexander Graf
2012-02-17 17:13 ` [PATCH 05/30] KVM: PPC: booke: Move vm core init/destroy out of booke.c Alexander Graf
2012-02-17 17:13 ` [PATCH 06/30] KVM: PPC: e500: rename e500_tlb.h to e500.h Alexander Graf
2012-02-17 17:13 ` [PATCH 07/30] KVM: PPC: e500: merge <asm/kvm_e500.h> into arch/powerpc/kvm/e500.h Alexander Graf
2012-02-17 17:13 ` [PATCH 08/30] KVM: PPC: e500: clean up arch/powerpc/kvm/e500.h Alexander Graf
2012-02-17 17:13 ` [PATCH 09/30] KVM: PPC: e500: refactor core-specific TLB code Alexander Graf
2012-02-17 17:13 ` [PATCH 10/30] KVM: PPC: e500: Track TLB1 entries with a bitmap Alexander Graf
2012-02-17 17:13 ` [PATCH 11/30] KVM: PPC: e500: emulate tlbilx Alexander Graf
2012-02-17 17:13 ` [PATCH 12/30] powerpc/booke: Provide exception macros with interrupt name Alexander Graf
2012-02-17 17:13 ` [PATCH 13/30] KVM: PPC: booke: category E.HV (GS-mode) support Alexander Graf
2012-02-17 21:12 ` Scott Wood
2012-02-20 11:40 ` Alexander Graf
2012-02-17 17:13 ` [PATCH 14/30] KVM: PPC: booke: standard PPC floating point support Alexander Graf
2012-02-17 17:13 ` [PATCH 15/30] KVM: PPC: e500mc support Alexander Graf
2012-02-17 17:13 ` [PATCH 16/30] KVM: PPC: e500mc: Add doorbell emulation support Alexander Graf
2012-02-17 21:55 ` Scott Wood
2012-02-17 21:57 ` Scott Wood
2012-02-20 11:49 ` Alexander Graf
2012-02-20 15:39 ` Scott Wood
2012-02-20 15:42 ` Alexander Graf
2012-02-17 17:13 ` [PATCH 17/30] KVM: PPC: e500mc: implicitly set MSR_GS Alexander Graf
2012-02-17 17:13 ` [PATCH 18/30] KVM: PPC: e500mc: Move r1/r2 restoration very early Alexander Graf
2012-02-17 17:13 ` [PATCH 19/30] KVM: PPC: e500mc: add load inst fixup Alexander Graf
2012-02-17 23:17 ` Scott Wood
2012-02-17 17:13 ` [PATCH 20/30] KVM: PPC: rename CONFIG_KVM_E500 -> CONFIG_KVM_E500V2 Alexander Graf
2012-02-17 17:13 ` [PATCH 21/30] KVM: PPC: make e500v2 and e500mc mutually exclusive Alexander Graf
2012-02-17 22:13 ` Scott Wood
2012-02-17 17:13 ` [PATCH 22/30] KVM: PPC: booke: remove leftover debugging Alexander Graf
2012-02-17 17:13 ` [PATCH 23/30] KVM: PPC: booke: deliver program int on emulation failure Alexander Graf
2012-02-17 17:13 ` [PATCH 24/30] KVM: PPC: booke: call resched after every exit Alexander Graf
2012-02-17 23:00 ` Scott Wood
2012-02-20 13:17 ` Alexander Graf
2012-02-20 17:18 ` Scott Wood [this message]
2012-02-17 17:13 ` [PATCH 25/30] KVM: PPC: booke: BOOKE_IRQPRIO_MAX is n+1 Alexander Graf
2012-02-17 17:13 ` [PATCH 26/30] KVM: PPC: bookehv: fix exit timing Alexander Graf
2012-02-17 17:13 ` [PATCH 27/30] KVM: PPC: bookehv: remove negation for CONFIG_64BIT Alexander Graf
2012-02-17 17:13 ` [PATCH 28/30] KVM: PPC: bookehv: remove SET_VCPU Alexander Graf
2012-02-17 17:13 ` [PATCH 29/30] KVM: PPC: bookehv: disable MAS register updates early Alexander Graf
2012-02-17 17:13 ` [PATCH 30/30] KVM: PPC: bookehv: add comment about shadow_msr Alexander Graf
-- strict thread matches above, loose matches on Subject: below --
2012-02-17 16:56 [PATCH 00/30] KVM: PPC: e500mc support Alexander Graf
2012-02-17 16:56 ` [PATCH 24/30] KVM: PPC: booke: call resched after every exit Alexander Graf
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