2015-12-14 20:16:47

by Denis Kirjanov

[permalink] [raw]
Subject: [PATCH v2 1/2] tracing: introduce TRACE_EVENT_FN_COND macro

TRACE_EVENT_FN can't be used in some circumstances
like invoking trace functions from offlined CPU due
to RCU usage.

This patch adds the TRACE_EVENT_FN_COND macro
to make such trace points conditional.

Signed-off-by: Denis Kirjanov <[email protected]>
---
include/linux/tracepoint.h | 4 ++++
include/trace/define_trace.h | 6 ++++++
include/trace/trace_events.h | 6 ++++++
3 files changed, 16 insertions(+)

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 696a339c..45b3fcf 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -493,6 +493,10 @@ extern void syscall_unregfunc(void);
#define TRACE_EVENT_FN(name, proto, args, struct, \
assign, print, reg, unreg) \
DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define TRACE_EVENT_FN_COND(name, proto, args, cond, struct, \
+ assign, print, reg, unreg) \
+ DECLARE_TRACE_CONDITION(name, PARAMS(proto), \
+ PARAMS(args), PARAMS(cond))
#define TRACE_EVENT_CONDITION(name, proto, args, cond, \
struct, assign, print) \
DECLARE_TRACE_CONDITION(name, PARAMS(proto), \
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index 2d8639e..6e3945f 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -40,6 +40,11 @@
assign, print, reg, unreg) \
DEFINE_TRACE_FN(name, reg, unreg)

+#undef TRACE_EVENT_FN_COND
+#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct, \
+ assign, print, reg, unreg) \
+ DEFINE_TRACE_FN(name, reg, unreg)
+
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args) \
DEFINE_TRACE(name)
@@ -93,6 +98,7 @@

#undef TRACE_EVENT
#undef TRACE_EVENT_FN
+#undef TRACE_EVENT_FN_COND
#undef TRACE_EVENT_CONDITION
#undef DECLARE_EVENT_CLASS
#undef DEFINE_EVENT
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index de996cf..170c93b 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -123,6 +123,12 @@ TRACE_MAKE_SYSTEM_STR();
TRACE_EVENT(name, PARAMS(proto), PARAMS(args), \
PARAMS(tstruct), PARAMS(assign), PARAMS(print)) \

+#undef TRACE_EVENT_FN_COND
+#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct, \
+ assign, print, reg, unreg) \
+ TRACE_EVENT_CONDITION(name, PARAMS(proto), PARAMS(args), PARAMS(cond), \
+ PARAMS(tstruct), PARAMS(assign), PARAMS(print)) \
+
#undef TRACE_EVENT_FLAGS
#define TRACE_EVENT_FLAGS(name, value) \
__TRACE_EVENT_FLAGS(name, value)
--
2.4.0


2015-12-14 20:16:55

by Denis Kirjanov

[permalink] [raw]
Subject: [PATCH v2 2/2] ./drmgr -c cpu -a -r gives the following warning:

[ 2327.035563]
RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 1
[ 2327.035564] no locks held by swapper/12/0.
[ 2327.035565]
stack backtrace:
[ 2327.035567] CPU: 12 PID: 0 Comm: swapper/12 Tainted: G S
4.3.0-rc3-00060-g353169a #5
[ 2327.035568] Call Trace:
[ 2327.035573] [c0000001d62578e0] [c0000000008977fc] .dump_stack+0x98/0xd4 (unreliable)
[ 2327.035577] [c0000001d6257960] [c000000000109bd8] .lockdep_rcu_suspicious+0x108/0x170
[ 2327.035580] [c0000001d62579f0] [c00000000006a1d0] .__trace_hcall_exit+0x2b0/0x2c0
[ 2327.035584] [c0000001d6257ab0] [c00000000006a2e8] plpar_hcall_norets_trace+0x70/0x8c
[ 2327.035588] [c0000001d6257b20] [c000000000067a14] .icp_hv_set_cpu_priority+0x54/0xc0
[ 2327.035592] [c0000001d6257ba0] [c000000000066c5c] .xics_teardown_cpu+0x5c/0xa0
[ 2327.035595] [c0000001d6257c20] [c0000000000747ac] .pseries_mach_cpu_die+0x6c/0x320
[ 2327.035598] [c0000001d6257cd0] [c0000000000439cc] .cpu_die+0x3c/0x60
[ 2327.035602] [c0000001d6257d40] [c0000000000183d8] .arch_cpu_idle_dead+0x28/0x40
[ 2327.035606] [c0000001d6257db0] [c0000000000ff1dc] .cpu_startup_entry+0x4fc/0x560
[ 2327.035610] [c0000001d6257ed0] [c000000000043728] .start_secondary+0x328/0x360
[ 2327.035614] [c0000001d6257f90] [c000000000008a6c] start_secondary_prolog+0x10/0x14
[ 2327.035620] cpu 12 (hwid 12) Ready to die...
[ 2327.144463] cpu 13 (hwid 13) Ready to die...
[ 2327.294180] cpu 14 (hwid 14) Ready to die...
[ 2327.403599] cpu 15 (hwid 15) Ready to die...

Make the hypervisor tracepoints conditional
by using TRACE_EVENT_FN_COND

Signed-off-by: Denis Kirjanov <[email protected]>

v2 changes:
- Use raw_smp_processor_id as suggested by BenH
since since hcalls can be called from preemptable sections
---
arch/powerpc/include/asm/trace.h | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/trace.h b/arch/powerpc/include/asm/trace.h
index 8e86b48..32e36b1 100644
--- a/arch/powerpc/include/asm/trace.h
+++ b/arch/powerpc/include/asm/trace.h
@@ -57,12 +57,14 @@ DEFINE_EVENT(ppc64_interrupt_class, timer_interrupt_exit,
extern void hcall_tracepoint_regfunc(void);
extern void hcall_tracepoint_unregfunc(void);

-TRACE_EVENT_FN(hcall_entry,
+TRACE_EVENT_FN_COND(hcall_entry,

TP_PROTO(unsigned long opcode, unsigned long *args),

TP_ARGS(opcode, args),

+ TP_CONDITION(cpu_online(raw_smp_processor_id())),
+
TP_STRUCT__entry(
__field(unsigned long, opcode)
),
@@ -76,13 +78,15 @@ TRACE_EVENT_FN(hcall_entry,
hcall_tracepoint_regfunc, hcall_tracepoint_unregfunc
);

-TRACE_EVENT_FN(hcall_exit,
+TRACE_EVENT_FN_COND(hcall_exit,

TP_PROTO(unsigned long opcode, unsigned long retval,
unsigned long *retbuf),

TP_ARGS(opcode, retval, retbuf),

+ TP_CONDITION(cpu_online(raw_smp_processor_id())),
+
TP_STRUCT__entry(
__field(unsigned long, opcode)
__field(unsigned long, retval)
--
2.4.0

2015-12-14 20:18:23

by Denis Kirjanov

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] ./drmgr -c cpu -a -r gives the following warning:

On 12/14/15, Denis Kirjanov <[email protected]> wrote:
> [ 2327.035563]
> RCU used illegally from offline CPU!
> rcu_scheduler_active = 1, debug_locks = 1
> [ 2327.035564] no locks held by swapper/12/0.
> [ 2327.035565]
> stack backtrace:
> [ 2327.035567] CPU: 12 PID: 0 Comm: swapper/12 Tainted: G S
> 4.3.0-rc3-00060-g353169a #5
> [ 2327.035568] Call Trace:
> [ 2327.035573] [c0000001d62578e0] [c0000000008977fc] .dump_stack+0x98/0xd4
> (unreliable)
> [ 2327.035577] [c0000001d6257960] [c000000000109bd8]
> .lockdep_rcu_suspicious+0x108/0x170
> [ 2327.035580] [c0000001d62579f0] [c00000000006a1d0]
> .__trace_hcall_exit+0x2b0/0x2c0
> [ 2327.035584] [c0000001d6257ab0] [c00000000006a2e8]
> plpar_hcall_norets_trace+0x70/0x8c
> [ 2327.035588] [c0000001d6257b20] [c000000000067a14]
> .icp_hv_set_cpu_priority+0x54/0xc0
> [ 2327.035592] [c0000001d6257ba0] [c000000000066c5c]
> .xics_teardown_cpu+0x5c/0xa0
> [ 2327.035595] [c0000001d6257c20] [c0000000000747ac]
> .pseries_mach_cpu_die+0x6c/0x320
> [ 2327.035598] [c0000001d6257cd0] [c0000000000439cc] .cpu_die+0x3c/0x60
> [ 2327.035602] [c0000001d6257d40] [c0000000000183d8]
> .arch_cpu_idle_dead+0x28/0x40
> [ 2327.035606] [c0000001d6257db0] [c0000000000ff1dc]
> .cpu_startup_entry+0x4fc/0x560
> [ 2327.035610] [c0000001d6257ed0] [c000000000043728]
> .start_secondary+0x328/0x360
> [ 2327.035614] [c0000001d6257f90] [c000000000008a6c]
> start_secondary_prolog+0x10/0x14
> [ 2327.035620] cpu 12 (hwid 12) Ready to die...
> [ 2327.144463] cpu 13 (hwid 13) Ready to die...
> [ 2327.294180] cpu 14 (hwid 14) Ready to die...
> [ 2327.403599] cpu 15 (hwid 15) Ready to die...
>
> Make the hypervisor tracepoints conditional
> by using TRACE_EVENT_FN_COND
>
> Signed-off-by: Denis Kirjanov <[email protected]>
Please ignore this patch with the broken subject
>
> v2 changes:
> - Use raw_smp_processor_id as suggested by BenH
> since since hcalls can be called from preemptable sections
> ---
> arch/powerpc/include/asm/trace.h | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/trace.h
> b/arch/powerpc/include/asm/trace.h
> index 8e86b48..32e36b1 100644
> --- a/arch/powerpc/include/asm/trace.h
> +++ b/arch/powerpc/include/asm/trace.h
> @@ -57,12 +57,14 @@ DEFINE_EVENT(ppc64_interrupt_class,
> timer_interrupt_exit,
> extern void hcall_tracepoint_regfunc(void);
> extern void hcall_tracepoint_unregfunc(void);
>
> -TRACE_EVENT_FN(hcall_entry,
> +TRACE_EVENT_FN_COND(hcall_entry,
>
> TP_PROTO(unsigned long opcode, unsigned long *args),
>
> TP_ARGS(opcode, args),
>
> + TP_CONDITION(cpu_online(raw_smp_processor_id())),
> +
> TP_STRUCT__entry(
> __field(unsigned long, opcode)
> ),
> @@ -76,13 +78,15 @@ TRACE_EVENT_FN(hcall_entry,
> hcall_tracepoint_regfunc, hcall_tracepoint_unregfunc
> );
>
> -TRACE_EVENT_FN(hcall_exit,
> +TRACE_EVENT_FN_COND(hcall_exit,
>
> TP_PROTO(unsigned long opcode, unsigned long retval,
> unsigned long *retbuf),
>
> TP_ARGS(opcode, retval, retbuf),
>
> + TP_CONDITION(cpu_online(raw_smp_processor_id())),
> +
> TP_STRUCT__entry(
> __field(unsigned long, opcode)
> __field(unsigned long, retval)
> --
> 2.4.0
>
>