Currently the syscall_meta structures for the syscall tracepoints are placed in the __syscall_metadata section, and at link time, the linker makes one large array of all these syscall metadata structures. On boot up, this array is read (much like the initcall sections) and the syscall data is processed. The problem is that there is no guarantee that gcc will place complex structures nicely together in an array format. Two structures in the same file may be placed awkwardly, because gcc has no clue that they are suppose to be in an array. A hack was used previous to force the alignment to 4, to pack the structures together. But this caused alignment issues with other architectures (sparc). Instead of packing the structures into an array, the structures' addresses are now put into the __syscall_metadata section. As pointers are always the natural alignment, gcc should always pack them tightly together (otherwise initcall, extable, etc would also fail). By having the pointers to the structures in the section, we can still iterate the trace_events without causing unnecessary alignment problems with other architectures, or depending on the current behaviour of gcc that will likely change in the future just to tick us kernel developers off a little more. The __syscall_metadata section is also moved into the .init.data section as it is now only needed at boot up. Suggested-by: David Miller <davem@davemloft.net> Acked-by: David S. Miller <davem@davemloft.net> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There is no need for syscall_exit_fields as the syscall exit event class can already host the fields in its structure, like most other trace events do by default. Use that default behavior instead. Following this scheme, we don't need anymore to override the get_fields() callback of the syscall exit event class either. Hence both syscall_exit_fields and syscall_get_exit_fields() can be removed. Also changed some indentation to keep the following under 80 characters: ".fields = LIST_HEAD_INIT(event_class_syscall_exit.fields)," Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D301C0E.8090408@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
All syscall exit events have the same fields. The kernel size drops 2.5K: text data bss dec hex filename 7018612 2034376 7251132 16304120 f8c7f8 vmlinux.o.orig 7018612 2031888 7251132 16301632 f8be40 vmlinux.o Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4BFA3746.8070100@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
tracepoint_probe_unregister() does not synchronize against the probe callbacks, so do that explicitly. This properly serializes the callbacks and the free of the data used therein. Also, use this_cpu_ptr() where possible. Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1274438476.1674.1702.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts: include/linux/ftrace_event.h include/trace/ftrace.h kernel/trace/trace_event_perf.c kernel/trace/trace_kprobe.c kernel/trace/trace_syscalls.c Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Avoid the swevent hash-table by using per-tracepoint hlists. Also, avoid conditionals on the fast path by ordering with probe unregister so that we should never get on the callback path without the data being there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20100521090710.473188012@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Improves performance. Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1274259525.5605.10352.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
When we've got but a single event per tracepoint there is no reason to try and multiplex it so don't. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now that the trace_event structure is embedded in the ftrace_event_call structure, there is no need for the ftrace_event_call id field. The id field is the same as the trace_event type field. Removing the id and re-arranging the structure brings down the tracepoint footprint by another 5K. text data bss dec hex filename 4913961 1088356 861512 6863829 68bbd5 vmlinux.orig 4895024 1023812 861512 6780348 6775bc vmlinux.print 4894944 1018052 861512 6774508 675eec vmlinux.id Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently, every event has its own trace_event structure. This is fine since the structure is needed anyway. But the print function structure (trace_event_functions) is now separate. Since the output of the trace event is done by the class (with the exception of events defined by DEFINE_EVENT_PRINT), it makes sense to have the class define the print functions that all events in the class can use. This makes a bigger deal with the syscall events since all syscall events use the same class. The savings here is another 30K. text data bss dec hex filename 4913961 1088356 861512 6863829 68bbd5 vmlinux.orig 4900382 1048964 861512 6810858 67ecea vmlinux.init 4900446 1049028 861512 6810986 67ed6a vmlinux.preprint 4895024 1023812 861512 6780348 6775bc vmlinux.print To accomplish this, and to let the class know what event is being printed, the event structure is embedded in the ftrace_event_call structure. This should not be an issues since the event structure was created for each event anyway. Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>