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* [PATCH 5/5] processor: jiffies-based bm_check, bugfixes
@ 2004-12-23 14:08 Dominik Brodowski
       [not found] ` <20041223140849.GE7973-X3ehHDuj6sIIGcDfoQAp7BvVK+yQ3ZXh@public.gmane.org>
  0 siblings, 1 reply; 5+ messages in thread
From: Dominik Brodowski @ 2004-12-23 14:08 UTC (permalink / raw)
  To: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
	len.brown-ral2JQCrhuEAvxtiuMwx3w

Make the bm_activity depend on "jiffies", instead of numbers
of the check being called. This means bus mastering activity
is assumed if bm_check isn't called; and multiple calls during
one jiffy will be |='ed.

Also, two fixups where promotion and demotion were mixed up.

Signed-off-by: Dominik Brodowski <linux-JhLEnvuH02M@public.gmane.org>
---

 drivers/acpi/processor_idle.c |   19 ++++++++++++++++---
 include/acpi/processor.h      |    1 +
 2 files changed, 17 insertions(+), 3 deletions(-)

Index: linux-2.6.10-rc3+bk-acpi/drivers/acpi/processor_idle.c
===================================================================
--- linux-2.6.10-rc3+bk-acpi.orig/drivers/acpi/processor_idle.c	2004-12-23 14:25:32.385908579 +0100
+++ linux-2.6.10-rc3+bk-acpi/drivers/acpi/processor_idle.c	2004-12-23 14:39:58.360081349 +0100
@@ -193,8 +193,18 @@
 	 */
 	if (pr->flags.bm_check) {
 		u32		bm_status = 0;
+		unsigned long	diff = jiffies - pr->power.bm_check_timestamp;
 
-		pr->power.bm_activity <<= 1;
+		if (diff > 32)
+			diff = 32;
+
+		while (diff) {
+			/* if we didn't get called, assume there was busmaster activity */
+			diff--;
+			if (diff)
+				pr->power.bm_activity |= 0x1;
+			pr->power.bm_activity <<= 1;
+		}
 
 		acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
 			&bm_status, ACPI_MTX_DO_NOT_LOCK);
@@ -213,6 +223,9 @@
 				|| (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 				pr->power.bm_activity++;
 		}
+
+		pr->power.bm_check_timestamp = jiffies;
+
 		/*
 		 * Apply bus mastering demotion policy.  Automatically demote
 		 * to avoid a faulty transition.  Note that the processor
@@ -439,13 +452,13 @@
 
 		if (higher) {
 			cx->promotion.state  = higher;
-			cx->demotion.threshold.ticks = cx->latency_ticks;
+			cx->promotion.threshold.ticks = cx->latency_ticks;
 			if (cx->type >= ACPI_STATE_C2)
 				cx->promotion.threshold.count = 4;
 			else
 				cx->promotion.threshold.count = 10;
 			if (higher->type == ACPI_STATE_C3)
-				cx->demotion.threshold.bm = 0x0F;
+				cx->promotion.threshold.bm = 0x0F;
 		}
 
 		higher = cx;
Index: linux-2.6.10-rc3+bk-acpi/include/acpi/processor.h
===================================================================
--- linux-2.6.10-rc3+bk-acpi.orig/include/acpi/processor.h	2004-12-23 13:21:12.000000000 +0100
+++ linux-2.6.10-rc3+bk-acpi/include/acpi/processor.h	2004-12-23 14:41:47.558845116 +0100
@@ -54,6 +54,7 @@
 
 struct acpi_processor_power {
 	struct acpi_processor_cx *state;
+	unsigned long		bm_check_timestamp;
 	u32			default_state;
 	u32			bm_activity;
 	int			count;


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^ permalink raw reply	[flat|nested] 5+ messages in thread
* RE: [PATCH 5/5] processor: jiffies-based bm_check
@ 2005-01-21 21:03 Pallipadi, Venkatesh
  0 siblings, 0 replies; 5+ messages in thread
From: Pallipadi, Venkatesh @ 2005-01-21 21:03 UTC (permalink / raw)
  To: Dominik Brodowski, Brown, Len; +Cc: ACPI Developers, Moore, Robert

 

>-----Original Message-----
>From: Dominik Brodowski [mailto:linux-X3ehHDuj6sIIGcDfoQAp7BvVK+yQ3ZXh@public.gmane.org] 
>Sent: Friday, January 21, 2005 8:24 AM
>To: Brown, Len
>Cc: ACPI Developers; Pallipadi, Venkatesh; Moore, Robert
>Subject: Re: [PATCH 5/5] processor: jiffies-based bm_check
>
>On Thu, Jan 20, 2005 at 11:08:06PM -0500, Len Brown wrote:
>> On Thu, 2004-12-23 at 15:11, Len Brown wrote:
>> 
>> > Didn't apply the jiffies part yet.
>> 
>> I've applied it now. (attached as jiffy.patch)
>> 
>> However, "threshold.bm = 0xF" was written when
>> HZ = 100 yielding 40ms, but this
>> becomes 4ms for HZ = 1000.
>> 
>> While I don't know what the optimal value is for
>> the bus master history threshold, it seemed like
>> a good idea for it to default to about 40ms per
>> the original code until we know better.
>> 
>> So I've also applied the attached bm_history.patch
>> to default this to 0xFFFFFFFF for HZ = 1000 (32ms)
>> and it is tunable via /sys/module/processor/parameters/bm_history
>> 
>> what do you think?
>
>This sounds sensible to do. Note that the "diff" measured in 
>idle() will
>become problematic once "tickless" systems are implemented -- 
>we'll sleep
>for multiple jiffies then, and there was _no_ bm activiy in 
>between. We need
>to sort that out somehow...
>
>	Dominik


How about using gettimeofday here and using that in place of jiffies?

-Venki


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^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2005-01-21 21:03 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2004-12-23 14:08 [PATCH 5/5] processor: jiffies-based bm_check, bugfixes Dominik Brodowski
     [not found] ` <20041223140849.GE7973-X3ehHDuj6sIIGcDfoQAp7BvVK+yQ3ZXh@public.gmane.org>
2004-12-23 20:11   ` Len Brown
2005-01-21  4:08     ` [PATCH 5/5] processor: jiffies-based bm_check Len Brown
2005-01-21 16:23       ` Dominik Brodowski
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2005-01-21 21:03 Pallipadi, Venkatesh

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