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From: "Jan Beulich" <JBeulich@suse.com>
To: David Vrabel <david.vrabel@citrix.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	xen-devel@lists.xen.org,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Subject: Re: [PATCH 3/3] xen/events: schedule if the interrupted task is in a preemptible hypercall
Date: Wed, 12 Feb 2014 11:59:46 +0000	[thread overview]
Message-ID: <52FB7042020000780011BAD0@nat28.tlf.novell.com> (raw)
In-Reply-To: <1392146352-16381-4-git-send-email-david.vrabel@citrix.com>

>>> On 11.02.14 at 20:19, David Vrabel <david.vrabel@citrix.com> wrote:
> --- a/drivers/xen/events/events_base.c
> +++ b/drivers/xen/events/events_base.c
> @@ -1254,6 +1254,12 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
>  
>  	irq_exit();
>  	set_irq_regs(old_regs);
> +
> +#ifndef CONFIG_PREEMPT
> +	if ( __this_cpu_read(xed_nesting_count) == 0
> +	     && is_preemptible_hypercall(regs) )
> +		_cond_resched();
> +#endif

I don't think this can be done here - a 64-bit x86 kernel would
generally be on the IRQ stack, and I don't think scheduling
should be done in this state.

Jan

  reply	other threads:[~2014-02-12 11:59 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-11 19:19 [PATCHv1 0/3]: xen: voluntary preemption for privcmd hypercalls David Vrabel
2014-02-11 19:19 ` [PATCH 1/3] x86/xen: allow for privcmd hypercalls to be preempted David Vrabel
2014-02-12  9:38   ` Ian Campbell
2014-02-12 10:10     ` Andrew Cooper
2014-02-12 10:18       ` Ian Campbell
2014-02-11 19:19 ` [PATCH 2/3] arm/xen: add stub is_preemptible_hypercall() David Vrabel
2014-02-11 19:19 ` [PATCH 3/3] xen/events: schedule if the interrupted task is in a preemptible hypercall David Vrabel
2014-02-12 11:59   ` Jan Beulich [this message]
2014-02-12 12:54     ` David Vrabel
2014-02-12 13:56       ` Jan Beulich
2014-02-12 16:35         ` David Vrabel
2014-02-12 16:47           ` Jan Beulich

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