Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-10 Thread Will Deacon
On Tue, Oct 04, 2016 at 09:06:18AM +0200, Peter Zijlstra wrote: > On Tue, Oct 04, 2016 at 03:29:33PM +1100, Michael Ellerman wrote: > > Peter Zijlstra writes: > > > So it would be good to also explain why PPC needs this in the first > > > place. > > > > Unfortunately I don't really know the code,

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-06 Thread Peter Zijlstra
On Wed, Oct 05, 2016 at 09:53:38PM +0200, Jiri Olsa wrote: > On Wed, Oct 05, 2016 at 10:09:21AM +0200, Jiri Olsa wrote: > > On Tue, Oct 04, 2016 at 03:29:33PM +1100, Michael Ellerman wrote: > > > > SNIP > > > > > Which is where we cope with the possibility that we couldn't emulate the > > > instr

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-05 Thread Jiri Olsa
On Wed, Oct 05, 2016 at 10:09:21AM +0200, Jiri Olsa wrote: > On Tue, Oct 04, 2016 at 03:29:33PM +1100, Michael Ellerman wrote: > > SNIP > > > Which is where we cope with the possibility that we couldn't emulate the > > instruction that hit the breakpoint. Seems that is not an issue on x86, > > or

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-05 Thread Jan Stancek
, "Jan Stancek" > > Sent: Tuesday, 4 October, 2016 6:08:27 AM > Subject: Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic > context > > Jiri Olsa writes: > > > The trinity syscall fuzzer triggered following WARN on powerpc: > >

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-05 Thread Jiri Olsa
On Tue, Oct 04, 2016 at 03:29:33PM +1100, Michael Ellerman wrote: SNIP > Which is where we cope with the possibility that we couldn't emulate the > instruction that hit the breakpoint. Seems that is not an issue on x86, > or it's handled elsewhere? > > We should fix emulate_step() if it failed t

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-05 Thread Jiri Olsa
On Tue, Oct 04, 2016 at 03:08:27PM +1100, Michael Ellerman wrote: > Jiri Olsa writes: > > > The trinity syscall fuzzer triggered following WARN on powerpc: > > WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278 > > ... > > NIP [c093aedc] .hw_breakpoint_handler+0x28

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-04 Thread Peter Zijlstra
On Tue, Oct 04, 2016 at 03:29:33PM +1100, Michael Ellerman wrote: > Peter Zijlstra writes: > > So it would be good to also explain why PPC needs this in the first > > place. > > Unfortunately I don't really know the code, and the original author is AWOL. > > But AFAICS perf_event_disable() is on

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-03 Thread Michael Ellerman
Peter Zijlstra writes: > On Mon, Oct 03, 2016 at 03:29:32PM +0200, Jiri Olsa wrote: >> On Fri, Sep 23, 2016 at 06:37:47PM +0200, Peter Zijlstra wrote: >> > On Wed, Sep 21, 2016 at 03:55:34PM +0200, Jiri Olsa wrote: >> > > stack backtrace: >> > > CPU: 9 PID: 2998 Comm: ls Tainted: GW

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-03 Thread Michael Ellerman
Jiri Olsa writes: > The trinity syscall fuzzer triggered following WARN on powerpc: > WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278 > ... > NIP [c093aedc] .hw_breakpoint_handler+0x28c/0x2b0 > LR [c093aed8] .hw_breakpoint_handler+0x288/0x2b0 > Call

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-03 Thread Peter Zijlstra
On Mon, Oct 03, 2016 at 03:29:32PM +0200, Jiri Olsa wrote: > On Fri, Sep 23, 2016 at 06:37:47PM +0200, Peter Zijlstra wrote: > > On Wed, Sep 21, 2016 at 03:55:34PM +0200, Jiri Olsa wrote: > > > The trinity syscall fuzzer triggered following WARN on powerpc: > > > WARNING: CPU: 9 PID: 2998 at arch

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-10-03 Thread Jiri Olsa
On Fri, Sep 23, 2016 at 06:37:47PM +0200, Peter Zijlstra wrote: > On Wed, Sep 21, 2016 at 03:55:34PM +0200, Jiri Olsa wrote: > > The trinity syscall fuzzer triggered following WARN on powerpc: > > WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278 > > ... > > NIP [c0

Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-09-23 Thread Peter Zijlstra
On Wed, Sep 21, 2016 at 03:55:34PM +0200, Jiri Olsa wrote: > The trinity syscall fuzzer triggered following WARN on powerpc: > WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278 > ... > NIP [c093aedc] .hw_breakpoint_handler+0x28c/0x2b0 > LR [c093aed8] .hw_b

[PATCH] perf powerpc: Don't call perf_event_disable from atomic context

2016-09-21 Thread Jiri Olsa
The trinity syscall fuzzer triggered following WARN on powerpc: WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278 ... NIP [c093aedc] .hw_breakpoint_handler+0x28c/0x2b0 LR [c093aed8] .hw_breakpoint_handler+0x288/0x2b0 Call Trace: [c002f7933580] [c00