Messages in this thread Patch in this message | | | From | Valentin Schneider <> | Subject | Re: [PATCH] tracing: Add __cpumask to denote a trace event field that is a cpumask_t | Date | Fri, 14 Oct 2022 18:21:41 +0100 |
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+Cc Douglas
On 14/10/22 08:04, Steven Rostedt wrote: > From: Steven Rostedt (Google) <rostedt@goodmis.org> > > The trace events have a __bitmask field that can be used for anything > that requires bitmasks. Although currently it is only used for CPU > masks, it could be used in the future for any type of bitmasks. > > There is some user space tooling that wants to know if a field is a CPU > mask and not just some random unsigned long bitmask. Introduce > "__cpumask()" helper functions that work the same as the current > __bitmask() helpers but displays in the format file: > > field:__data_loc cpumask_t *[] mask; offset:36; size:4; signed:0; > > Instead of: > > field:__data_loc unsigned long[] mask; offset:32; size:4; signed:0; > > The main difference is the type. Instead of "unsigned long" it is > "cpumask_t *". Note, this type field needs to be a real type in the > __dynamic_array() logic that both __cpumask and__bitmask use, but the > comparison field requires it to be a scalar type whereas cpumask_t is a > structure (non-scalar). But everything works when making it a pointer. > > Requested-by: Valentin Schneider <vschneid@redhat.com> > Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Thanks for spinning this out so quickly! I gave it a test against my IPI tracepoints, it's working OK with one (expected) change:
[ipi:ipi_send_cpumask] function __get_cpumask not defined CPU 0 is empty CPU 1 is empty CPU 3 is empty cpus=4 echo-173 [002] 11.859745: ipi_send_cpumask: [FAILED TO PARSE] cpumask=ARRAY[02, 00, 00, 00, 00, 00, 00, 00] callsite=0xffffffff81121013
so libtraceevent is going to need updating - I'm happy to do that (if you haven't done it already!)
Lastly, given all cpumasks have a (usable) size of nr_cpumask_bits, we can factor out the size argument, see below. Regardless:
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
--- diff --git a/include/trace/stages/stage1_struct_define.h b/include/trace/stages/stage1_struct_define.h index e1a9b8462b418..b6a9e60755fe0 100644 --- a/include/trace/stages/stage1_struct_define.h +++ b/include/trace/stages/stage1_struct_define.h @@ -33,7 +33,7 @@ #define __bitmask(item, nr_bits) __dynamic_array(char, item, -1) #undef __cpumask -#define __cpumask(item, nr_bits) __dynamic_array(char, item, -1) +#define __cpumask(item) __dynamic_array(char, item, -1) #undef __sockaddr #define __sockaddr(field, len) __dynamic_array(u8, field, len) diff --git a/include/trace/stages/stage2_data_offsets.h b/include/trace/stages/stage2_data_offsets.h index 4f096c30303b9..2c3838f5ee892 100644 --- a/include/trace/stages/stage2_data_offsets.h +++ b/include/trace/stages/stage2_data_offsets.h @@ -39,7 +39,7 @@ #define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1) #undef __cpumask -#define __cpumask(item, nr_bits) __dynamic_array(unsigned long, item, -1) +#define __cpumask(item) __dynamic_array(unsigned long, item, -1) #undef __sockaddr #define __sockaddr(field, len) __dynamic_array(u8, field, len) diff --git a/include/trace/stages/stage4_event_fields.h b/include/trace/stages/stage4_event_fields.h index 11cf5550494d2..52ccf0b9b1765 100644 --- a/include/trace/stages/stage4_event_fields.h +++ b/include/trace/stages/stage4_event_fields.h @@ -47,7 +47,7 @@ #define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1) #undef __cpumask -#define __cpumask(item, nr_bits) __dynamic_array(cpumask_t *, item, -1) +#define __cpumask(item) __dynamic_array(cpumask_t *, item, -1) #undef __sockaddr #define __sockaddr(field, len) __dynamic_array(u8, field, len) diff --git a/include/trace/stages/stage5_get_offsets.h b/include/trace/stages/stage5_get_offsets.h index 0d9386b0d320c..b3934b74c72d0 100644 --- a/include/trace/stages/stage5_get_offsets.h +++ b/include/trace/stages/stage5_get_offsets.h @@ -83,7 +83,7 @@ __bitmask_size_in_longs(nr_bits)) #undef __cpumask -#define __cpumask(item, nr_bits) __bitmask(item, nr_bits) +#define __cpumask(item) __bitmask(item, nr_cpumask_bits) #undef __rel_bitmask #define __rel_bitmask(item, nr_bits) __rel_dynamic_array(unsigned long, item, \ diff --git a/include/trace/stages/stage6_event_callback.h b/include/trace/stages/stage6_event_callback.h index 76774cb9acc89..e12e541fef42b 100644 --- a/include/trace/stages/stage6_event_callback.h +++ b/include/trace/stages/stage6_event_callback.h @@ -58,14 +58,14 @@ memcpy(__get_bitmask(dst), (src), __bitmask_size_in_bytes(nr_bits)) #undef __cpumask -#define __cpumask(item, nr_bits) __dynamic_array(unsigned long, item, -1) +#define __cpumask(item) __dynamic_array(unsigned long, item, -1) #undef __get_cpumask #define __get_cpumask(field) (char *)__get_dynamic_array(field) #undef __assign_cpumask -#define __assign_cpumask(dst, src, nr_bits) \ - memcpy(__get_cpumask(dst), (src), __bitmask_size_in_bytes(nr_bits)) +#define __assign_cpumask(dst, src) \ + memcpy(__get_cpumask(dst), (src), __bitmask_size_in_bytes(nr_cpumask_bits)) #undef __sockaddr #define __sockaddr(field, len) __dynamic_array(u8, field, len)
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