Messages in this thread Patch in this message | | | Date | Mon, 28 Feb 2011 08:22:30 -0800 | From | Greg KH <> | Subject | [09/68] x86, hpet: Disable per-cpu hpet timer if ARAT is supported |
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2.6.32-longterm review patch. If anyone has any objections, please let us know.
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From: Shaohua Li <shaohua.li@intel.com>
commit 39fe05e58c5e448601ce46e6b03900d5bf31c4b0 upstream.
If CPU support always running local APIC timer, per-cpu hpet timer could be disabled, which is useless and wasteful in such case. Let's leave the timers to others.
The effect is that we reserve less timers.
Signed-off-by: Shaohua Li <shaohua.li@intel.com> Cc: venkatesh.pallipadi@intel.com LKML-Reference: <20090812031612.GA10062@sli10-desk.sh.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Renninger <trenn@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- arch/x86/kernel/hpet.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -606,6 +606,8 @@ static void hpet_msi_capability_lookup(u if (hpet_msi_disable) return; + if (boot_cpu_has(X86_FEATURE_ARAT)) + return; id = hpet_readl(HPET_ID); num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT); @@ -894,10 +896,8 @@ int __init hpet_enable(void) if (id & HPET_ID_LEGSUP) { hpet_legacy_clockevent_register(); - hpet_msi_capability_lookup(2); return 1; } - hpet_msi_capability_lookup(0); return 0; out_nohpet: @@ -930,12 +930,20 @@ static __init int hpet_late_init(void) if (!hpet_virt_address) return -ENODEV; + if (hpet_readl(HPET_ID) & HPET_ID_LEGSUP) + hpet_msi_capability_lookup(2); + else + hpet_msi_capability_lookup(0); + hpet_reserve_platform_timers(hpet_readl(HPET_ID)); hpet_print_config(); if (hpet_msi_disable) return 0; + if (boot_cpu_has(X86_FEATURE_ARAT)) + return 0; + for_each_online_cpu(cpu) { hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu); }
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