Auto-detect the presence of HPET on ICH5 or newer platforms and enable HPET for broadcast timer. This gives a bigger upperlimit for tickless time tick and improves the power consumption in comparison to PIT as broadcast timer.
This patch: Change the broadcast timer, if a timer with higher rating becomes available. Signed-off-by: Venkatesh Pallipadi <[EMAIL PROTECTED]> --- Applies over linux-2.6.22-rc4-mm2 + tglx's patch-2.6.22-rc4-mm2-hrt4 patch The patchset had been baking for a while along with patch-2.6.22-rc*-hrt* for a while without breaking anything and redusing the number of timer interrupts with tickless on various platforms. kernel/time/tick-broadcast.c | 13 ++++++------- kernel/time/tick-common.c | 4 ++-- 2 files changed, 8 insertions(+), 9 deletions(-) Index: linux-2.6.22-rc5/kernel/time/tick-common.c =================================================================== --- linux-2.6.22-rc5.orig/kernel/time/tick-common.c 2007-06-17 08:52:07.000000000 +0200 +++ linux-2.6.22-rc5/kernel/time/tick-common.c 2007-06-17 08:52:10.000000000 +0200 @@ -200,7 +200,7 @@ static int tick_check_new_device(struct cpu = smp_processor_id(); if (!cpu_isset(cpu, newdev->cpumask)) - goto out; + goto out_bc; td = &per_cpu(tick_cpu_device, cpu); curdev = td->evtdev; @@ -265,7 +265,7 @@ out_bc: */ if (tick_check_broadcast_device(newdev)) ret = NOTIFY_STOP; -out: + spin_unlock_irqrestore(&tick_device_lock, flags); return ret; Index: linux-2.6.22-rc5/kernel/time/tick-broadcast.c =================================================================== --- linux-2.6.22-rc5.orig/kernel/time/tick-broadcast.c 2007-06-17 08:52:07.000000000 +0200 +++ linux-2.6.22-rc5/kernel/time/tick-broadcast.c 2007-06-17 08:52:10.000000000 +0200 @@ -64,8 +64,9 @@ static void tick_broadcast_start_periodi */ int tick_check_broadcast_device(struct clock_event_device *dev) { - if (tick_broadcast_device.evtdev || - (dev->features & CLOCK_EVT_FEAT_C3STOP)) + if ((tick_broadcast_device.evtdev && + tick_broadcast_device.evtdev->rating >= dev->rating) || + (dev->features & CLOCK_EVT_FEAT_C3STOP)) return 0; clockevents_exchange_device(NULL, dev); @@ -519,11 +520,9 @@ static void tick_broadcast_clear_oneshot */ void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { - if (bc->mode != CLOCK_EVT_MODE_ONESHOT) { - bc->event_handler = tick_handle_oneshot_broadcast; - clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); - bc->next_event.tv64 = KTIME_MAX; - } + bc->event_handler = tick_handle_oneshot_broadcast; + clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); + bc->next_event.tv64 = KTIME_MAX; } /* - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/