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>
This commit is contained in:
Todd Android Poynor 2010-12-23 01:52:44 +01:00 committed by Russell King
parent 875728807f
commit d13e5edd72

View file

@ -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