Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-31 Thread Andy Lutomirski
On Fri, Jan 30, 2015 at 7:12 PM, Andy Lutomirski wrote: > On Fri, Jan 30, 2015 at 5:28 PM, Sasha Levin wrote: >> On 01/30/2015 02:57 PM, Sasha Levin wrote: >>> On 01/28/2015 04:02 PM, Andy Lutomirski wrote: On Wed, Jan 28, 2015 at 9:48 AM, Paul E. McKenney wrote: > On Wed, Jan 28,

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-30 Thread Andy Lutomirski
On Fri, Jan 30, 2015 at 5:28 PM, Sasha Levin wrote: > On 01/30/2015 02:57 PM, Sasha Levin wrote: >> On 01/28/2015 04:02 PM, Andy Lutomirski wrote: >>> On Wed, Jan 28, 2015 at 9:48 AM, Paul E. McKenney >>> wrote: On Wed, Jan 28, 2015 at 08:33:06AM -0800, Andy Lutomirski wrote: > On Fri, J

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-30 Thread Sasha Levin
On 01/30/2015 02:57 PM, Sasha Levin wrote: > On 01/28/2015 04:02 PM, Andy Lutomirski wrote: >> On Wed, Jan 28, 2015 at 9:48 AM, Paul E. McKenney >> wrote: >>> On Wed, Jan 28, 2015 at 08:33:06AM -0800, Andy Lutomirski wrote: On Fri, Jan 23, 2015 at 5:25 PM, Andy Lutomirski wrote: >

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-30 Thread Sasha Levin
On 01/28/2015 04:02 PM, Andy Lutomirski wrote: > On Wed, Jan 28, 2015 at 9:48 AM, Paul E. McKenney > wrote: >> On Wed, Jan 28, 2015 at 08:33:06AM -0800, Andy Lutomirski wrote: >>> On Fri, Jan 23, 2015 at 5:25 PM, Andy Lutomirski >>> wrote: On Fri, Jan 23, 2015 at 12:48 PM, Sasha Levin >>>

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-28 Thread Andy Lutomirski
On Wed, Jan 28, 2015 at 9:48 AM, Paul E. McKenney wrote: > On Wed, Jan 28, 2015 at 08:33:06AM -0800, Andy Lutomirski wrote: >> On Fri, Jan 23, 2015 at 5:25 PM, Andy Lutomirski wrote: >> > On Fri, Jan 23, 2015 at 12:48 PM, Sasha Levin >> > wrote: >> >> On 01/23/2015 01:34 PM, Andy Lutomirski wro

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-28 Thread Andy Lutomirski
On Fri, Jan 23, 2015 at 5:25 PM, Andy Lutomirski wrote: > On Fri, Jan 23, 2015 at 12:48 PM, Sasha Levin wrote: >> On 01/23/2015 01:34 PM, Andy Lutomirski wrote: >>> On Fri, Jan 23, 2015 at 10:04 AM, Borislav Petkov wrote: On Fri, Jan 23, 2015 at 09:58:01AM -0800, Andy Lutomirski wrote:

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-28 Thread Paul E. McKenney
On Wed, Jan 28, 2015 at 08:33:06AM -0800, Andy Lutomirski wrote: > On Fri, Jan 23, 2015 at 5:25 PM, Andy Lutomirski wrote: > > On Fri, Jan 23, 2015 at 12:48 PM, Sasha Levin > > wrote: > >> On 01/23/2015 01:34 PM, Andy Lutomirski wrote: > >>> On Fri, Jan 23, 2015 at 10:04 AM, Borislav Petkov wro

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-23 Thread Andy Lutomirski
On Fri, Jan 23, 2015 at 12:48 PM, Sasha Levin wrote: > On 01/23/2015 01:34 PM, Andy Lutomirski wrote: >> On Fri, Jan 23, 2015 at 10:04 AM, Borislav Petkov wrote: >>> On Fri, Jan 23, 2015 at 09:58:01AM -0800, Andy Lutomirski wrote: > [ 543.999079] Call Trace: > [ 543.999079] dump_stack (

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-23 Thread Sasha Levin
On 01/23/2015 01:34 PM, Andy Lutomirski wrote: > On Fri, Jan 23, 2015 at 10:04 AM, Borislav Petkov wrote: >> On Fri, Jan 23, 2015 at 09:58:01AM -0800, Andy Lutomirski wrote: [ 543.999079] Call Trace: [ 543.999079] dump_stack (lib/dump_stack.c:52) [ 543.999079] lockdep_rcu_suspici

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-23 Thread Andy Lutomirski
On Fri, Jan 23, 2015 at 10:04 AM, Borislav Petkov wrote: > On Fri, Jan 23, 2015 at 09:58:01AM -0800, Andy Lutomirski wrote: >> > [ 543.999079] Call Trace: >> > [ 543.999079] dump_stack (lib/dump_stack.c:52) >> > [ 543.999079] lockdep_rcu_suspicious (kernel/locking/lockdep.c:4259) >> > [ 543.99

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-23 Thread Borislav Petkov
On Fri, Jan 23, 2015 at 09:58:01AM -0800, Andy Lutomirski wrote: > > [ 543.999079] Call Trace: > > [ 543.999079] dump_stack (lib/dump_stack.c:52) > > [ 543.999079] lockdep_rcu_suspicious (kernel/locking/lockdep.c:4259) > > [ 543.999079] atomic_notifier_call_chain (include/linux/rcupdate.h:892

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-23 Thread Andy Lutomirski
On Thu, Jan 22, 2015 at 1:52 PM, Sasha Levin wrote: > On 11/21/2014 04:26 PM, Andy Lutomirski wrote: >> We currently pretend that IST context is like standard exception >> context, but this is incorrect. IST entries from userspace are like >> standard exceptions except that they use per-cpu stack

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-22 Thread Sasha Levin
On 11/21/2014 04:26 PM, Andy Lutomirski wrote: > We currently pretend that IST context is like standard exception > context, but this is incorrect. IST entries from userspace are like > standard exceptions except that they use per-cpu stacks, so they are > atomic. IST entries from kernel space ar

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-05 Thread Andy Lutomirski
On Mon, Jan 5, 2015 at 1:46 PM, Tony Luck wrote: > On Wed, Dec 10, 2014 at 4:24 PM, Andy Lutomirski wrote: >> I think you need ist_begin_non_atomic() before local_irq_enable() and >> ist_end_non_atomic() after local_irq_disable(). Otherwise it should >> be good. > > In your x86/paranoid branch y

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2015-01-05 Thread Tony Luck
On Wed, Dec 10, 2014 at 4:24 PM, Andy Lutomirski wrote: > I think you need ist_begin_non_atomic() before local_irq_enable() and > ist_end_non_atomic() after local_irq_disable(). Otherwise it should > be good. In your x86/paranoid branch you added: prev_state = ist_enter(regs); ..

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-12-10 Thread Andy Lutomirski
On Wed, Dec 10, 2014 at 4:22 PM, Tony Luck wrote: > On Tue, Nov 25, 2014 at 10:58 AM, Borislav Petkov wrote: >> On Mon, Nov 24, 2014 at 03:52:10PM -0800, Andy Lutomirski wrote: >>> Dunno. Tony and Borislav -- when do you want the IST stack switching >>> stuff? >> >> I'd leave that up to Tony and

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-12-10 Thread Tony Luck
On Tue, Nov 25, 2014 at 10:58 AM, Borislav Petkov wrote: > On Mon, Nov 24, 2014 at 03:52:10PM -0800, Andy Lutomirski wrote: >> Dunno. Tony and Borislav -- when do you want the IST stack switching >> stuff? > > I'd leave that up to Tony and his testbench. I mean, we can hammer on > it as much as we

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-12-01 Thread Paul E. McKenney
On Thu, Nov 27, 2014 at 03:03:22PM +0800, Lai Jiangshan wrote: > > > > > Signed-off-by: Paul E. McKenney > > Reviewed-by: Lai Jiangshan Thank you, recorded! > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > index 8749f43f3f05..fc0236992655 100644 > > --- a/kernel/rcu/tree.c > > +++

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-26 Thread Lai Jiangshan
> > Signed-off-by: Paul E. McKenney > Reviewed-by: Lai Jiangshan > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 8749f43f3f05..fc0236992655 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -759,39 +759,71 @@ void rcu_irq_enter(void) > /** > * rcu_nmi_enter -

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-25 Thread Paul E. McKenney
On Tue, Nov 25, 2014 at 07:58:03PM +0100, Borislav Petkov wrote: > On Mon, Nov 24, 2014 at 03:52:10PM -0800, Andy Lutomirski wrote: > > Dunno. Tony and Borislav -- when do you want the IST stack switching > > stuff? > > I'd leave that up to Tony and his testbench. I mean, we can hammer on > it as

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-25 Thread Borislav Petkov
On Mon, Nov 24, 2014 at 03:52:10PM -0800, Andy Lutomirski wrote: > Dunno. Tony and Borislav -- when do you want the IST stack switching > stuff? I'd leave that up to Tony and his testbench. I mean, we can hammer on it as much as we can and it can pass all testing locally but the real fun starts on

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-25 Thread Paul E. McKenney
On Mon, Nov 24, 2014 at 03:50:58PM -0800, Paul E. McKenney wrote: > On Mon, Nov 24, 2014 at 03:35:55PM -0800, Andy Lutomirski wrote: > > On Mon, Nov 24, 2014 at 3:31 PM, Paul E. McKenney > > wrote: > > > On Mon, Nov 24, 2014 at 02:57:54PM -0800, Paul E. McKenney wrote: > > >> On Mon, Nov 24, 2014

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Andy Lutomirski
On Mon, Nov 24, 2014 at 3:50 PM, Paul E. McKenney wrote: > On Mon, Nov 24, 2014 at 03:35:55PM -0800, Andy Lutomirski wrote: >> On Mon, Nov 24, 2014 at 3:31 PM, Paul E. McKenney >> wrote: >> > On Mon, Nov 24, 2014 at 02:57:54PM -0800, Paul E. McKenney wrote: >> >> On Mon, Nov 24, 2014 at 02:36:18P

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Paul E. McKenney
On Mon, Nov 24, 2014 at 03:35:55PM -0800, Andy Lutomirski wrote: > On Mon, Nov 24, 2014 at 3:31 PM, Paul E. McKenney > wrote: > > On Mon, Nov 24, 2014 at 02:57:54PM -0800, Paul E. McKenney wrote: > >> On Mon, Nov 24, 2014 at 02:36:18PM -0800, Andy Lutomirski wrote: > >> > On Mon, Nov 24, 2014 at 2

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Andy Lutomirski
On Mon, Nov 24, 2014 at 3:31 PM, Paul E. McKenney wrote: > On Mon, Nov 24, 2014 at 02:57:54PM -0800, Paul E. McKenney wrote: >> On Mon, Nov 24, 2014 at 02:36:18PM -0800, Andy Lutomirski wrote: >> > On Mon, Nov 24, 2014 at 2:34 PM, Paul E. McKenney >> > wrote: >> > > On Mon, Nov 24, 2014 at 01:35:

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Paul E. McKenney
On Mon, Nov 24, 2014 at 02:57:54PM -0800, Paul E. McKenney wrote: > On Mon, Nov 24, 2014 at 02:36:18PM -0800, Andy Lutomirski wrote: > > On Mon, Nov 24, 2014 at 2:34 PM, Paul E. McKenney > > wrote: > > > On Mon, Nov 24, 2014 at 01:35:01PM -0800, Paul E. McKenney wrote: > > [ . . . ] > > > > And

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Paul E. McKenney
On Mon, Nov 24, 2014 at 02:36:18PM -0800, Andy Lutomirski wrote: > On Mon, Nov 24, 2014 at 2:34 PM, Paul E. McKenney > wrote: > > On Mon, Nov 24, 2014 at 01:35:01PM -0800, Paul E. McKenney wrote: [ . . . ] > > And the following Promela model claims that your approach works. > > Should I trust it

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Andy Lutomirski
On Mon, Nov 24, 2014 at 2:34 PM, Paul E. McKenney wrote: > On Mon, Nov 24, 2014 at 01:35:01PM -0800, Paul E. McKenney wrote: >> On Mon, Nov 24, 2014 at 01:02:51PM -0800, Andy Lutomirski wrote: >> > On Mon, Nov 24, 2014 at 12:54 PM, Paul E. McKenney >> > wrote: >> > > On Mon, Nov 24, 2014 at 12:22

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Paul E. McKenney
On Mon, Nov 24, 2014 at 01:35:01PM -0800, Paul E. McKenney wrote: > On Mon, Nov 24, 2014 at 01:02:51PM -0800, Andy Lutomirski wrote: > > On Mon, Nov 24, 2014 at 12:54 PM, Paul E. McKenney > > wrote: > > > On Mon, Nov 24, 2014 at 12:22:13PM -0800, Andy Lutomirski wrote: > > >> On Sat, Nov 22, 2014

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Paul E. McKenney
On Mon, Nov 24, 2014 at 01:02:51PM -0800, Andy Lutomirski wrote: > On Mon, Nov 24, 2014 at 12:54 PM, Paul E. McKenney > wrote: > > On Mon, Nov 24, 2014 at 12:22:13PM -0800, Andy Lutomirski wrote: > >> On Sat, Nov 22, 2014 at 3:41 PM, Paul E. McKenney > >> wrote: > >> > On Fri, Nov 21, 2014 at 09:

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Paul E. McKenney
On Mon, Nov 24, 2014 at 12:54:41PM -0800, Paul E. McKenney wrote: > On Mon, Nov 24, 2014 at 12:22:13PM -0800, Andy Lutomirski wrote: > > On Sat, Nov 22, 2014 at 3:41 PM, Paul E. McKenney > > wrote: > > > On Fri, Nov 21, 2014 at 09:53:29PM -0800, Andy Lutomirski wrote: > > >> On Fri, Nov 21, 2014 a

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Andy Lutomirski
On Mon, Nov 24, 2014 at 12:54 PM, Paul E. McKenney wrote: > On Mon, Nov 24, 2014 at 12:22:13PM -0800, Andy Lutomirski wrote: >> On Sat, Nov 22, 2014 at 3:41 PM, Paul E. McKenney >> wrote: >> > On Fri, Nov 21, 2014 at 09:53:29PM -0800, Andy Lutomirski wrote: >> >> On Fri, Nov 21, 2014 at 8:20 PM,

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Paul E. McKenney
On Mon, Nov 24, 2014 at 12:22:13PM -0800, Andy Lutomirski wrote: > On Sat, Nov 22, 2014 at 3:41 PM, Paul E. McKenney > wrote: > > On Fri, Nov 21, 2014 at 09:53:29PM -0800, Andy Lutomirski wrote: > >> On Fri, Nov 21, 2014 at 8:20 PM, Paul E. McKenney > >> wrote: > >> > On Fri, Nov 21, 2014 at 06:0

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Andy Lutomirski
On Sat, Nov 22, 2014 at 3:41 PM, Paul E. McKenney wrote: > On Fri, Nov 21, 2014 at 09:53:29PM -0800, Andy Lutomirski wrote: >> On Fri, Nov 21, 2014 at 8:20 PM, Paul E. McKenney >> wrote: >> > On Fri, Nov 21, 2014 at 06:00:14PM -0800, Andy Lutomirski wrote: >> >> On Fri, Nov 21, 2014 at 3:38 PM, P

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-24 Thread Andy Lutomirski
On Sat, Nov 22, 2014 at 9:20 AM, Borislav Petkov wrote: > On Fri, Nov 21, 2014 at 01:26:08PM -0800, Andy Lutomirski wrote: >> We currently pretend that IST context is like standard exception >> context, but this is incorrect. IST entries from userspace are like >> standard exceptions except that

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-22 Thread Paul E. McKenney
On Fri, Nov 21, 2014 at 09:53:29PM -0800, Andy Lutomirski wrote: > On Fri, Nov 21, 2014 at 8:20 PM, Paul E. McKenney > wrote: > > On Fri, Nov 21, 2014 at 06:00:14PM -0800, Andy Lutomirski wrote: > >> On Fri, Nov 21, 2014 at 3:38 PM, Paul E. McKenney > >> wrote: > >> > On Fri, Nov 21, 2014 at 03:0

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-22 Thread Borislav Petkov
On Fri, Nov 21, 2014 at 01:26:08PM -0800, Andy Lutomirski wrote: > We currently pretend that IST context is like standard exception > context, but this is incorrect. IST entries from userspace are like > standard exceptions except that they use per-cpu stacks, so they are > atomic. IST entries fr

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Andy Lutomirski
On Fri, Nov 21, 2014 at 8:20 PM, Paul E. McKenney wrote: > On Fri, Nov 21, 2014 at 06:00:14PM -0800, Andy Lutomirski wrote: >> On Fri, Nov 21, 2014 at 3:38 PM, Paul E. McKenney >> wrote: >> > On Fri, Nov 21, 2014 at 03:06:48PM -0800, Andy Lutomirski wrote: >> >> On Fri, Nov 21, 2014 at 2:55 PM, P

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Paul E. McKenney
On Fri, Nov 21, 2014 at 06:00:14PM -0800, Andy Lutomirski wrote: > On Fri, Nov 21, 2014 at 3:38 PM, Paul E. McKenney > wrote: > > On Fri, Nov 21, 2014 at 03:06:48PM -0800, Andy Lutomirski wrote: > >> On Fri, Nov 21, 2014 at 2:55 PM, Paul E. McKenney > >> wrote: > >> > On Fri, Nov 21, 2014 at 02:1

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Andy Lutomirski
On Fri, Nov 21, 2014 at 3:38 PM, Paul E. McKenney wrote: > On Fri, Nov 21, 2014 at 03:06:48PM -0800, Andy Lutomirski wrote: >> On Fri, Nov 21, 2014 at 2:55 PM, Paul E. McKenney >> wrote: >> > On Fri, Nov 21, 2014 at 02:19:17PM -0800, Andy Lutomirski wrote: >> >> On Fri, Nov 21, 2014 at 2:07 PM, P

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Paul E. McKenney
On Fri, Nov 21, 2014 at 03:06:48PM -0800, Andy Lutomirski wrote: > On Fri, Nov 21, 2014 at 2:55 PM, Paul E. McKenney > wrote: > > On Fri, Nov 21, 2014 at 02:19:17PM -0800, Andy Lutomirski wrote: > >> On Fri, Nov 21, 2014 at 2:07 PM, Paul E. McKenney > >> wrote: > >> > On Fri, Nov 21, 2014 at 01:3

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Andy Lutomirski
On Fri, Nov 21, 2014 at 2:55 PM, Paul E. McKenney wrote: > On Fri, Nov 21, 2014 at 02:19:17PM -0800, Andy Lutomirski wrote: >> On Fri, Nov 21, 2014 at 2:07 PM, Paul E. McKenney >> wrote: >> > On Fri, Nov 21, 2014 at 01:32:50PM -0800, Andy Lutomirski wrote: >> >> On Fri, Nov 21, 2014 at 1:26 PM, A

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Paul E. McKenney
On Fri, Nov 21, 2014 at 02:19:17PM -0800, Andy Lutomirski wrote: > On Fri, Nov 21, 2014 at 2:07 PM, Paul E. McKenney > wrote: > > On Fri, Nov 21, 2014 at 01:32:50PM -0800, Andy Lutomirski wrote: > >> On Fri, Nov 21, 2014 at 1:26 PM, Andy Lutomirski > >> wrote: > >> > We currently pretend that IS

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Andy Lutomirski
On Fri, Nov 21, 2014 at 2:07 PM, Paul E. McKenney wrote: > On Fri, Nov 21, 2014 at 01:32:50PM -0800, Andy Lutomirski wrote: >> On Fri, Nov 21, 2014 at 1:26 PM, Andy Lutomirski wrote: >> > We currently pretend that IST context is like standard exception >> > context, but this is incorrect. IST en

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Frederic Weisbecker
On Fri, Nov 21, 2014 at 02:07:04PM -0800, Paul E. McKenney wrote: > On Fri, Nov 21, 2014 at 01:32:50PM -0800, Andy Lutomirski wrote: > > On Fri, Nov 21, 2014 at 1:26 PM, Andy Lutomirski > > wrote: > > > We currently pretend that IST context is like standard exception > > > context, but this is in

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Paul E. McKenney
On Fri, Nov 21, 2014 at 01:32:50PM -0800, Andy Lutomirski wrote: > On Fri, Nov 21, 2014 at 1:26 PM, Andy Lutomirski wrote: > > We currently pretend that IST context is like standard exception > > context, but this is incorrect. IST entries from userspace are like > > standard exceptions except th

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Paul E. McKenney
On Fri, Nov 21, 2014 at 01:26:08PM -0800, Andy Lutomirski wrote: > We currently pretend that IST context is like standard exception > context, but this is incorrect. IST entries from userspace are like > standard exceptions except that they use per-cpu stacks, so they are > atomic. IST entries fr

Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

2014-11-21 Thread Andy Lutomirski
On Fri, Nov 21, 2014 at 1:26 PM, Andy Lutomirski wrote: > We currently pretend that IST context is like standard exception > context, but this is incorrect. IST entries from userspace are like > standard exceptions except that they use per-cpu stacks, so they are > atomic. IST entries from kerne