Re: #PF from NMI

2020-11-16 Thread Steven Rostedt
On Sat, 14 Nov 2020 00:13:58 +0100 Thomas Gleixner wrote: > nmi: > ... > trace_hardirqs_off_finish() { > if (!this_cpu_read(tracing_irq_cpu)) { >this_cpu_write(tracing_irq_cpu, 1); >... > } > ... > perf() > > #PF > save_cr2() > > irqentry_enter() >

Re: #PF from NMI

2020-11-13 Thread Paul E. McKenney
x40 > > [ 139.226753] exc_page_fault+0x38/0x4c0 > > [ 139.226753] asm_exc_page_fault+0x1e/0x30 > > ... > > > [ 139.226757] perf_callchain_user+0xf4/0x280 > > > > Which is a #PF from NMI context, which is perfectly fine. However > > __rcu_irq_enter_che

Re: #PF from NMI

2020-11-13 Thread Thomas Gleixner
fault+0x1e/0x30 ... > [ 139.226757] perf_callchain_user+0xf4/0x280 > > Which is a #PF from NMI context, which is perfectly fine. However > __rcu_irq_enter_check_tick() is triggering WARN. > > AFAICT the right thing is to simply remove the warn like so. > > --- > diff --g

Re: #PF from NMI

2020-11-13 Thread Andy Lutomirski
24 38 23 93 f8 08 > [ 139.226766] RSP: 002b:7ffcf13cde60 EFLAGS: 00010246 > [ 139.226766] RAX: 7fb0c309c2b0 RBX: 7fb0c5a73500 RCX: > 0006 > [ 139.226766] RDX: RSI: 000a RDI: > fc2c9fd0 > [ 139.226767] RBP: 0

Re: #PF from NMI

2020-11-13 Thread Paul E. McKenney
38 23 93 f8 08 > [ 139.226766] RSP: 002b:7ffcf13cde60 EFLAGS: 00010246 > [ 139.226766] RAX: 7fb0c309c2b0 RBX: 7fb0c5a73500 RCX: > 0006 > [ 139.226766] RDX: RSI: 000a RDI: > fc2c9fd0 > [ 139.226767] RBP: 00

#PF from NMI

2020-11-13 Thread Peter Zijlstra
is a #PF from NMI context, which is perfectly fine. However __rcu_irq_enter_check_tick() is triggering WARN. AFAICT the right thing is to simply remove the warn like so. --- diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 430ba58d8bfe..9bda92d8b914 100644 --- a/kernel/rcu/tree.c +++ b/ke