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Commit 85b67bcb authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by David S. Miller
Browse files

perf, bpf: minimize the size of perf_trace_() tracepoint handler 



move trace_call_bpf() into helper function to minimize the size
of perf_trace_*() tracepoint handlers.
    text	   data	    bss	    dec	 	   hex	filename
10541679	5526646	2945024	19013349	1221ee5	vmlinux_before
10509422	5526646	2945024	18981092	121a0e4	vmlinux_after

It may seem that perf_fetch_caller_regs() can also be moved,
but that is incorrect, since ip/sp will be wrong.

bpf+tracepoint performance is not affected, since
perf_swevent_put_recursion_context() is now inlined.
export_symbol_gpl can also be dropped.

No measurable change in normal perf tracepoints.

Suggested-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c60c9840

include/linux/trace_events.h

+5 −0
Original line number Diff line number Diff line
@@ -609,6 +609,11 @@ extern void ftrace_profile_free_filter(struct perf_event *event); 
void perf_trace_buf_update(void *record, u16 type);

void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp);



void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,

			       struct trace_event_call *call, u64 count,

			       struct pt_regs *regs, struct hlist_head *head,

			       struct task_struct *task);



static inline void

perf_trace_buf_submit(void *raw_data, int size, int rctx, u16 type,

		       u64 count, struct pt_regs *regs, void *head,

include/trace/perf.h

+3 −10
Original line number Diff line number Diff line
@@ -64,15 +64,8 @@ perf_trace_##call(void *__data, proto) \ 
									\

	{ assign; }							\

									\

	if (prog) {							\

		*(struct pt_regs **)entry = __regs;			\

		if (!trace_call_bpf(prog, entry) || hlist_empty(head)) { \

			perf_swevent_put_recursion_context(rctx);	\

			return;						\

		}							\

	}								\

	perf_trace_buf_submit(entry, __entry_size, rctx,		\

			      event_call->event.type, __count, __regs,	\

	perf_trace_run_bpf_submit(entry, __entry_size, rctx,		\

				  event_call, __count, __regs,		\

				  head, __task);			\

}

kernel/events/core.c

+19 −1
Original line number Diff line number Diff line
@@ -6741,7 +6741,6 @@ void perf_swevent_put_recursion_context(int rctx) 


	put_recursion_context(swhash->recursion, rctx);

}

EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context);



void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)

{
@@ -6998,6 +6997,25 @@ static int perf_tp_event_match(struct perf_event *event, 
	return 1;

}



void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,

			       struct trace_event_call *call, u64 count,

			       struct pt_regs *regs, struct hlist_head *head,

			       struct task_struct *task)

{

	struct bpf_prog *prog = call->prog;



	if (prog) {

		*(struct pt_regs **)raw_data = regs;

		if (!trace_call_bpf(prog, raw_data) || hlist_empty(head)) {

			perf_swevent_put_recursion_context(rctx);

			return;

		}

	}

	perf_tp_event(call->event.type, count, raw_data, size, regs, head,

		      rctx, task);

}

EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit);



void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,

		   struct pt_regs *regs, struct hlist_head *head, int rctx,

		   struct task_struct *task)