[lttng-dev] [PATCH] compaction: make tracepoints condtional on CONFIG_COMPACTION
bruce.ashfield at gmail.com
bruce.ashfield at gmail.com
Wed Aug 3 15:23:27 EDT 2022
From: Bruce Ashfield <bruce.ashfield at gmail.com>
When building against a v5.19 mips kernel, the following errors
were triggered:
| lttng-modules-2.13.4/src/probes/../../include/instrumentation/events/compaction.h:105:42: note: expected 'struct compact_control *' but argument is of type 'struct compact_control *'
| 105 | TP_PROTO(struct compact_control *cc,
| | ~~~~~~~~~~~~~~~~~~~~~~~~^~
| lttng-modules-2.13.4/src/probes/../../include/lttng/tracepoint-event-impl.h:779:68: note: in definition of macro 'LTTNG_TRACEPOINT_EVENT_CLASS_CODE'
| 779 | static inline size_t __event_get_align__##_name(void *__tp_locvar, _proto) \
| | ^~~~~~
| lttng-modules-2.13.4/src/probes/../../include/lttng/tracepoint-event-impl.h:106:50: note: in expansion of macro 'PARAMS'
| 106 | LTTNG_TRACEPOINT_EVENT_CLASS_CODE(_name, PARAMS(_proto), PARAMS(_args), , , \
| | ^~~~~~
| lttng-modules-2.13.4/src/probes/../../include/lttng/tracepoint-event-impl.h:41:9: note: in expansion of macro 'LTTNG_TRACEPOINT_EVENT_CLASS'
| 41 | LTTNG_TRACEPOINT_EVENT_CLASS(map, \
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
| lttng-modules-2.13.4/src/probes/../../include/lttng/tracepoint-event-impl.h:42:30: note: in expansion of macro 'PARAMS'
| 42 | PARAMS(proto), \
| | ^~~~~~
| lttng-modules-2.13.4/src/probes/../../include/instrumentation/events/compaction.h:101:1: note: in expansion of macro 'LTTNG_TRACEPOINT_EVENT_MAP'
| 101 | LTTNG_TRACEPOINT_EVENT_MAP(mm_compaction_migratepages,
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~
| lttng-modules-2.13.4/src/probes/../../include/instrumentation/events/compaction.h:105:9: note: in expansion of macro 'TP_PROTO'
| 105 | TP_PROTO(struct compact_control *cc,
| | ^~~~~~~~
| lttng-modules-2.13.4/src/probes/../../include/instrumentation/events/compaction.h:112:57: error: invalid use of undefined type 'struct compact_control'
...
| lttng-modules-2.13.4/src/probes/../../include/instrumentation/events/compaction.h:108:25: warning: 'struct compact_control' declared inside parameter list will not be visible outside of this definition or declaration
| 108 | TP_PROTO(struct compact_control *cc,
| | ^~~~~~~~~~~~~~~
| lttng-modules-2.13.4/src/probes/../../include/lttng/tracepoint-event-impl.h:159:43: note: in definition of macro 'LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP'
| 159 | void __event_template_proto___##_template(_proto);
| | ^~~~~~
| lttng-modules-2.13.4/src/probes/../../include/lttng/tracepoint-event-impl.h:45:61: note: in expansion of macro 'PARAMS'
| 45 | LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP(map, name, map, PARAMS(proto), PARAMS(args))
| | ^~~~~~
| lttng-modules-2.13.4/src/probes/../../include/instrumentation/events/compaction.h:104:1: note: in expansion of macro 'LTTNG_TRACEPOINT_EVENT_MAP'
| 104 | LTTNG_TRACEPOINT_EVENT_MAP(mm_compaction_migratepages,
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~
| lttng-modules-2.13.4/src/probes/../../include/instrumentation/events/compaction.h:108:9: note: in expansion of macro 'TP_PROTO'
| 108 | TP_PROTO(struct compact_control *cc,
| | ^~~~~~~~
| lttng-modules-2.13.4/src/probes/../../include/lttng/tracepoint-event-impl.h:159:6: error: conflicting types for '__event_template_proto___compaction_migratepages'; have 'void(struct compact_control *, unsigned int)'
| 159 | void __event_template_proto___##_template(_proto);
| | ^~~~~~~~~~~~~~~~~~~~~~~~~
| lttng-modules-2.13.4/src/probes/../../include/lttng/tracepoint-event-impl.h:45:9: note: in expansion of macro 'LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP'
| 45 | LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP(map, name, map, PARAMS(proto), PARAMS(args))
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The root cause appears to be that this particular mips kernel does not
have CONFIG_COMPACTION avaiable, and hence we end up with the struct
declaration within this tracepoint, and then conflicting types.
While putting the conditional around only compaction_migratepages seemed
sufficient to get the build working, it doesn't look like any of the
tracepoints should be valid, so we extend it to all definitions.
Signed-off-by: Bruce Ashfield <bruce.ashfield at gmail.com>
---
Hi all,
This was found during the update of the yocto project reference
kernel to 5.19. Out of all the supported architectures, only
mips failed during the build of lttng-modules.
Specifically, it seems like the lack of CONFIG_COMPACTION being
enabled in the kernel was the significant issue. Only one of the
tracepoints blew up, but I can't see how any of them would be
valid in this scenario, or why it would be limited to mips.
While I don't think this is the right fix, this is what got me
up and passing sanity testing, so I wanted to send the change
and see what the actual, correct fix would be :)
Cheers,
Bruce
include/instrumentation/events/compaction.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/include/instrumentation/events/compaction.h b/include/instrumentation/events/compaction.h
index ecae39a..155804a 100644
--- a/include/instrumentation/events/compaction.h
+++ b/include/instrumentation/events/compaction.h
@@ -9,6 +9,8 @@
#include <linux/types.h>
#include <lttng/kernel-version.h>
+#ifdef CONFIG_COMPACTION
+
#if LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,0,0)
LTTNG_TRACEPOINT_EVENT_CLASS(compaction_isolate_template,
@@ -97,6 +99,7 @@ LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP(compaction_isolate_template,
#endif /* #else #if LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,0,0) */
+
#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,18,0))
LTTNG_TRACEPOINT_EVENT_MAP(mm_compaction_migratepages,
@@ -182,6 +185,8 @@ LTTNG_TRACEPOINT_EVENT_MAP(mm_compaction_migratepages,
)
#endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,16,0)) */
+#endif /* CONFIG_COMPACTION */
+
#endif /* LTTNG_TRACE_COMPACTION_H */
/* This part must be outside protection */
--
2.25.1
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