From: Gleb Natapov <gleb@redhat.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: kvm@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 02/11] Add "handle page fault" PV helper.
Date: Mon, 2 Nov 2009 18:04:10 +0200 [thread overview]
Message-ID: <20091102160410.GF27911@redhat.com> (raw)
In-Reply-To: <20091102092214.GB8933@elte.hu>
On Mon, Nov 02, 2009 at 10:22:14AM +0100, Ingo Molnar wrote:
>
> * Gleb Natapov <gleb@redhat.com> wrote:
>
> > diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
> > index f4cee90..14707dc 100644
> > --- a/arch/x86/mm/fault.c
> > +++ b/arch/x86/mm/fault.c
> > @@ -952,6 +952,9 @@ do_page_fault(struct pt_regs *regs, unsigned long error_code)
> > int write;
> > int fault;
> >
> > + if (arch_handle_page_fault(regs, error_code))
> > + return;
> > +
>
> This patch is not acceptable unless it's done cleaner. Currently we
> already have 3 callbacks in do_page_fault() (kmemcheck, mmiotrace,
> notifier), and this adds a fourth one. Please consolidate them into a
> single callback site, this is a hotpath on x86.
>
This call is patched out by paravirt patching mechanism so overhead should be
zero for non paravirt cases. What do you want to achieve by consolidate
them into single callback? I mean the code will still exist and will have to be
executed on every #PF. Is the goal to move them out of line?
> And please always Cc: the x86 maintainers to patches that touch x86
> code.
>
Will do.
--
Gleb.
next prev parent reply other threads:[~2009-11-02 16:04 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-01 11:56 [PATCH 00/11] KVM: Add asynchronous page fault for PV guest Gleb Natapov
2009-11-01 11:56 ` [PATCH 01/11] Add shared memory hypercall to PV Linux guest Gleb Natapov
2009-11-02 4:27 ` Rik van Riel
2009-11-02 7:07 ` Gleb Natapov
2009-11-02 12:18 ` Avi Kivity
2009-11-02 16:18 ` Gleb Natapov
2009-11-03 5:15 ` Avi Kivity
2009-11-03 7:16 ` Gleb Natapov
2009-11-03 7:40 ` Avi Kivity
2009-11-01 11:56 ` [PATCH 02/11] Add "handle page fault" PV helper Gleb Natapov
2009-11-02 9:22 ` Ingo Molnar
2009-11-02 16:04 ` Gleb Natapov [this message]
2009-11-02 16:12 ` Ingo Molnar
2009-11-02 16:22 ` Gleb Natapov
2009-11-02 16:29 ` Ingo Molnar
2009-11-02 16:31 ` Gleb Natapov
2009-11-02 17:42 ` Gleb Natapov
2009-11-08 11:36 ` Ingo Molnar
2009-11-08 12:43 ` Avi Kivity
2009-11-08 12:51 ` Ingo Molnar
2009-11-08 13:01 ` Avi Kivity
2009-11-08 13:05 ` Ingo Molnar
2009-11-08 13:08 ` Avi Kivity
2009-11-08 16:44 ` H. Peter Anvin
2009-11-08 16:47 ` Ingo Molnar
2009-11-02 19:03 ` Rik van Riel
2009-11-02 19:33 ` Avi Kivity
2009-11-02 23:35 ` Rik van Riel
2009-11-03 4:57 ` Avi Kivity
2009-11-05 6:44 ` Tian, Kevin
2009-11-05 8:22 ` Avi Kivity
2009-11-01 11:56 ` [PATCH 03/11] Handle asynchronous page fault in a PV guest Gleb Natapov
2009-11-02 12:38 ` Avi Kivity
2009-11-02 15:54 ` Gleb Natapov
2009-11-03 14:14 ` Marcelo Tosatti
2009-11-03 14:25 ` Gleb Natapov
2009-11-03 14:32 ` Marcelo Tosatti
2009-11-03 14:38 ` Avi Kivity
2009-11-01 11:56 ` [PATCH 04/11] Export __get_user_pages_fast Gleb Natapov
2009-11-02 9:23 ` Ingo Molnar
2009-11-01 11:56 ` [PATCH 05/11] Add get_user_pages() variant that fails if major fault is required Gleb Natapov
2009-11-02 19:05 ` Rik van Riel
2009-11-01 11:56 ` [PATCH 06/11] Inject asynchronous page fault into a guest if page is swapped out Gleb Natapov
2009-11-02 12:56 ` Avi Kivity
2009-11-02 15:41 ` Gleb Natapov
2009-11-01 11:56 ` [PATCH 07/11] Retry fault before vmentry Gleb Natapov
2009-11-02 13:03 ` Avi Kivity
2009-11-01 11:56 ` [PATCH 08/11] Add "wait for page" hypercall Gleb Natapov
2009-11-02 13:05 ` Avi Kivity
2009-11-02 15:13 ` Gleb Natapov
2009-11-02 15:19 ` Avi Kivity
2009-11-01 11:56 ` [PATCH 09/11] Maintain preemptability count even for !CONFIG_PREEMPT kernels Gleb Natapov
2009-11-02 9:24 ` Ingo Molnar
2009-11-01 11:56 ` [PATCH 10/11] Handle async PF in non preemptable context Gleb Natapov
2009-11-01 11:56 ` [PATCH 11/11] Send async PF when guest is not in userspace too Gleb Natapov
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