Re: [RFC v3 1/2] x86/xen: add xen_is_preemptible_hypercall()

2015-01-22 Thread Luis R. Rodriguez
On Thu, Jan 22, 2015 at 09:44:12PM +, Andrew Cooper wrote: > On 22/01/2015 21:09, Luis R. Rodriguez wrote: > > On Thu, Jan 22, 2015 at 12:01:50PM -0800, Andy Lutomirski wrote: > >> On Thu, Jan 22, 2015 at 11:30 AM, Luis R. Rodriguez > >> wrote: > >>> On Wed, Jan 21, 2015 at 07:07:36PM -0800,

Re: [RFC v3 1/2] x86/xen: add xen_is_preemptible_hypercall()

2015-01-22 Thread Andrew Cooper
On 22/01/2015 21:09, Luis R. Rodriguez wrote: > On Thu, Jan 22, 2015 at 12:01:50PM -0800, Andy Lutomirski wrote: >> On Thu, Jan 22, 2015 at 11:30 AM, Luis R. Rodriguez wrote: >>> On Wed, Jan 21, 2015 at 07:07:36PM -0800, Andy Lutomirski wrote: On Wed, Jan 21, 2015 at 6:17 PM, Luis R. Rodrigue

Re: [RFC v3 1/2] x86/xen: add xen_is_preemptible_hypercall()

2015-01-22 Thread Luis R. Rodriguez
On Thu, Jan 22, 2015 at 12:01:50PM -0800, Andy Lutomirski wrote: > On Thu, Jan 22, 2015 at 11:30 AM, Luis R. Rodriguez wrote: > > On Wed, Jan 21, 2015 at 07:07:36PM -0800, Andy Lutomirski wrote: > >> On Wed, Jan 21, 2015 at 6:17 PM, Luis R. Rodriguez > >> wrote: > >> > From: "Luis R. Rodriguez"

Re: [RFC v3 1/2] x86/xen: add xen_is_preemptible_hypercall()

2015-01-22 Thread Andy Lutomirski
On Thu, Jan 22, 2015 at 11:30 AM, Luis R. Rodriguez wrote: > On Wed, Jan 21, 2015 at 07:07:36PM -0800, Andy Lutomirski wrote: >> On Wed, Jan 21, 2015 at 6:17 PM, Luis R. Rodriguez >> wrote: >> > From: "Luis R. Rodriguez" >> > >> > On kernels with voluntary or no preemption we can run >> > into s

Re: [RFC v3 1/2] x86/xen: add xen_is_preemptible_hypercall()

2015-01-22 Thread Luis R. Rodriguez
On Wed, Jan 21, 2015 at 07:07:36PM -0800, Andy Lutomirski wrote: > On Wed, Jan 21, 2015 at 6:17 PM, Luis R. Rodriguez > wrote: > > From: "Luis R. Rodriguez" > > > > On kernels with voluntary or no preemption we can run > > into situations where a hypercall issued through userspace > > will linger

Re: [RFC v3 1/2] x86/xen: add xen_is_preemptible_hypercall()

2015-01-21 Thread Andy Lutomirski
On Wed, Jan 21, 2015 at 6:17 PM, Luis R. Rodriguez wrote: > From: "Luis R. Rodriguez" > > On kernels with voluntary or no preemption we can run > into situations where a hypercall issued through userspace > will linger around as it addresses sub-operatiosn in kernel > context (multicalls). Such o

[RFC v3 1/2] x86/xen: add xen_is_preemptible_hypercall()

2015-01-21 Thread Luis R. Rodriguez
From: "Luis R. Rodriguez" On kernels with voluntary or no preemption we can run into situations where a hypercall issued through userspace will linger around as it addresses sub-operatiosn in kernel context (multicalls). Such operations can trigger soft lockup detection. We want to address a way