From a42c362980430be74b77ec8f374964f61062379f Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 9 Sep 2012 18:39:28 +0100 Subject: [PATCH] ARM: Add irqtime accounting support Add support for irq time accounting. This commit prepares ARM by adding the call to enable_sched_clock_irqtime() in sched_clock(). We introduce a new kernel parameter - irqtime - which takes an integer. -1 for auto, 0 for disabled, and 1 for enabled. Auto mode selects IRQ accounting if we have a sched_clock() tick rate greater than 1MHz. Frederic Weisbecker is working on a patch set which moves the IRQ_TIME_ACCOUNTING into arch/, so that part is not incorporated into this patch; this facility becomes available on ARM only when both this patch and Frederic's patches are merged. Signed-off-by: Russell King --- arch/arm/kernel/sched_clock.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index 27d186abbc06..9b8451a4330f 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -25,6 +26,9 @@ struct clock_data { static void sched_clock_poll(unsigned long wrap_ticks); static DEFINE_TIMER(sched_clock_timer, sched_clock_poll, 0, 0); +static int irqtime = -1; + +core_param(irqtime, irqtime, int, 0400); static struct clock_data cd = { .mult = NSEC_PER_SEC / HZ, @@ -145,6 +149,10 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) */ cd.epoch_ns = 0; + /* Enable IRQ time accounting if we have a fast enough sched_clock */ + if (irqtime > 0 || (irqtime == -1 && rate >= 1000000)) + enable_sched_clock_irqtime(); + pr_debug("Registered %pF as sched_clock source\n", read); }