From 7467571f4480b273007517b26297c07154c73924 Mon Sep 17 00:00:00 2001 From: Tero Kristo Date: Thu, 24 Feb 2011 17:19:23 +0200 Subject: cpuidle: menu: fixed wrapping timers at 4.294 seconds Cpuidle menu governor is using u32 as a temporary datatype for storing nanosecond values which wrap around at 4.294 seconds. This causes errors in predicted sleep times resulting in higher than should be C state selection and increased power consumption. This also breaks cpuidle state residency statistics. cc: stable@kernel.org # .32.x through .39.x Signed-off-by: Tero Kristo Signed-off-by: Len Brown --- drivers/cpuidle/governors/menu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index f508690..c47f3d0 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -237,6 +237,7 @@ static int menu_select(struct cpuidle_device *dev) unsigned int power_usage = -1; int i; int multiplier; + struct timespec t; if (data->needs_update) { menu_update(dev); @@ -251,8 +252,9 @@ static int menu_select(struct cpuidle_device *dev) return 0; /* determine the expected residency time, round up */ + t = ktime_to_timespec(tick_nohz_get_sleep_length()); data->expected_us = - DIV_ROUND_UP((u32)ktime_to_ns(tick_nohz_get_sleep_length()), 1000); + t.tv_sec * USEC_PER_SEC + t.tv_nsec / NSEC_PER_USEC; data->bucket = which_bucket(data->expected_us); -- cgit v1.1 From 02c68a02018669d1817c43c42de800975cbec467 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 1 Apr 2011 16:59:53 -0400 Subject: x86 idle: clarify AMD erratum 400 workaround The workaround for AMD erratum 400 uses the term "c1e" falsely suggesting: 1. Intel C1E is somehow involved 2. All AMD processors with C1E are involved Use the string "amd_c1e" instead of simply "c1e" to clarify that this workaround is specific to AMD's version of C1E. Use the string "e400" to clarify that the workaround is specific to AMD processors with Erratum 400. This patch is text-substitution only, with no functional change. cc: x86@kernel.org Acked-by: Borislav Petkov Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index d615b7d..431ab11 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -161,7 +161,7 @@ static void lapic_timer_check_state(int state, struct acpi_processor *pr, if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) return; - if (c1e_detected) + if (amd_e400_c1e_detected) type = ACPI_STATE_C1; /* -- cgit v1.1 From 3b70b2e5fcf6315eb833a1bcc2b810bdc75484ff Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 1 Apr 2011 15:08:48 -0400 Subject: x86 idle floppy: deprecate disable_hlt() Plan to remove floppy_disable_hlt in 2012, an ancient workaround with comments that it should be removed. This allows us to remove clutter and a run-time branch from the idle code. WARN_ONCE() on invocation until it is removed. cc: x86@kernel.org cc: stable@kernel.org # .39.x Signed-off-by: Len Brown --- drivers/block/floppy.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 77fc76f..20aea9b 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -1038,6 +1038,7 @@ static void floppy_disable_hlt(void) { unsigned long flags; + WARN_ONCE(1, "floppy_disable_hlt() scheduled for removal in 2012"); spin_lock_irqsave(&floppy_hlt_lock, flags); if (!hlt_disabled) { hlt_disabled = 1; -- cgit v1.1