commit 0e3853d202e8b2720bc4c674dc58849b2662c8f8
author Oleg Nesterov <oleg@redhat.com> Thu Mar 28 19:19:11 2013 +0100
committer Oleg Nesterov <oleg@redhat.com> Sat Apr 13 15:32:00 2013 +0200
tree 1985c7d62717dd07c2e3957acbb66515dc0ce65d
parent 456fdbcb8648a20f56977efbc6f13e28936fcf0b

uprobes/tracing: Kill the pointless local_save_flags/preempt_count calls

uprobe_trace_func() is never called with irqs or preemption
disabled, no need to ask preempt_count() or local_save_flags().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Anton Arapov <anton@redhat.com>

kernel/trace/trace_uprobe.c

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 8e00901..43d258d 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -492,17 +492,13 @@
 	struct ring_buffer_event *event;
 	struct ring_buffer *buffer;
 	u8 *data;
-	int size, i, pc;
-	unsigned long irq_flags;
+	int size, i;
 	struct ftrace_event_call *call = &tu->call;
 
-	local_save_flags(irq_flags);
-	pc = preempt_count();
-
 	size = sizeof(*entry) + tu->size;
 
 	event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
-						  size, irq_flags, pc);
+						  size, 0, 0);
 	if (!event)
 		return 0;
 
@@ -513,7 +509,7 @@
 		call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
 
 	if (!filter_current_check_discard(buffer, call, entry, event))
-		trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
+		trace_buffer_unlock_commit(buffer, event, 0, 0);
 
 	return 0;
 }