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authorTodd Android Poynor <toddpoynor@google.com>2010-12-23 01:52:44 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-12-24 09:37:59 +0000
commitd13e5edd7284bedcf5952e1b6490e39ad843cb91 (patch)
tree3fd22e4592bfe8ba175d231c706a9816ecaa594b
parent875728807ff001b67a1e0535de5ad2cd3c41d47c (diff)
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ARM: 6540/1: Stop irqsoff trace on return to user
If the irqsoff tracer is in use, stop tracing the interrupt disable interval when returning to userspace. Tracing userspace execution time as interrupts disabled time is not helpful for kernel performance analysis purposes. Only do so if the irqsoff tracer is enabled, to avoid overhead for lockdep, which doesn't care. Signed-off-by: Todd Poynor <toddpoynor@google.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/kernel/entry-common.S6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 8bfa98757cd2..80bf8cd88d7c 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -29,6 +29,9 @@ ret_fast_syscall:
ldr r1, [tsk, #TI_FLAGS]
tst r1, #_TIF_WORK_MASK
bne fast_work_pending
+#if defined(CONFIG_IRQSOFF_TRACER)
+ asm_trace_hardirqs_on
+#endif
/* perform architecture specific actions before user return */
arch_ret_to_user r1, lr
@@ -65,6 +68,9 @@ ret_slow_syscall:
tst r1, #_TIF_WORK_MASK
bne work_pending
no_work_pending:
+#if defined(CONFIG_IRQSOFF_TRACER)
+ asm_trace_hardirqs_on
+#endif
/* perform architecture specific actions before user return */
arch_ret_to_user r1, lr