Title: Methods and apparatus for static and dynamic power management of computer systems
Abstract: According to the present invention, methods and apparatus are provided for static and dynamic power management of computer systems. A power authority manages power usage levels in computer systems by monitoring power consumption levels and providing power consumption information to the various systems. In one example, the power authority updates power tables to vary aggregate power consumption levels.
Patent Number: 6,986,069 Issued on 01/10/2006 to Oehler, et al.
| Inventors:
|
Oehler; Richard R. (Somers, NY);
Zeitler, Jr.; Carl (Austin, TX);
Simpson; Richard O. (Austin, TX)
|
| Assignee:
|
Newisys, Inc. (Austin, TX)
|
| Appl. No.:
|
188271 |
| Filed:
|
July 1, 2002 |
| Current U.S. Class: |
713/320; 713/340; 713/300 |
| Current Intern'l Class: |
G06F 1/32 (20060101); G06F 1/28 (20060101); G06F 1/26 (20060101) |
| Field of Search: |
713/300,320,322,340
|
References Cited [Referenced By]
U.S. Patent Documents
Other References
HyperTransport ™ I/O Link Specification Revision 1.03. HyperTransport
™ Consortium, Oct. 10, 2001, Copyright © 2001 HyperTransport Technology Consortium.
|
Primary Examiner: Lee; Thomas
Assistant Examiner: Bae; Ji H.
Attorney, Agent or Firm: Beyer Weaver & Thomas, LLP
Claims
What is claimed is:
1. An apparatus, comprising:
a plurality of computer systems, each computer system including a memory coupled
to a processor and each computer system having a power consumption level, wherein
an aggregate power consumption level comprises a combination of the power consumption
levels associated with the plurality of computer systems;
a power source providing power to the plurality of computer systems;
a power authority subsystem for manipulating the aggregate power consumption
levels by managing the power consumption levels of the plurality of computer systems,
wherein managing the power consumption of the plurality of computer systems comprises
providing power consumption information to a plurality of service processors, wherein
each of the plurality of computer systems includes one or more service processors.
2. The apparatus of claim 1, wherein the power source has a maximum power output
less than the aggregate power consumption levels.
3. The apparatus of claim 1, wherein the power authority subsystem manages power
consumption levels to minimize aggregate power consumption.
4. The apparatus of claim 2, wherein the power authority is configured to manage
the power consumption of the plurality of computer systems so that the aggregate
power consumption of the plurality of computer systems does not exceed the maximum
power output or the power source.
5. The apparatus of claim 1, wherein managing the power consumption levels of
the plurality of computer systems comprises providing power consumption information
to the plurality of computer systems.
6. The apparatus of claim 5, wherein managing the power consumption of the plurality
of computer systems comprises writing power consumption information into the power
tables associated with the plurality of computer systems.
7. The apparatus of claim 6, wherein the power tables are Advanced Configuration
and Power Interface tables.
8. The apparatus of claim 6, wherein the power source is a power supply.
9. The apparatus of claim 7, wherein the plurality of computer systems have distinct
address spaces.
10. The apparatus of claim 6, wherein each computer system is associated with
a service processor.
11. The apparatus of claim 9, wherein managing the power consumption of the plurality
of computer systems comprises providing power consumption information before reboot
sequences of the plurality of computer systems are completed.
12. The apparatus of claim 6, wherein managing the power consumption of the plurality
of computer systems comprises providing power consumption information after reboot
sequences of the plurality of computer systems are completed.
13. The apparatus of claim 12, wherein power tables are updated dynamically during
runtime using power consumption information.
14. A method for managing power consumption across multiple systems, the method comprising:
identifying a maximum power output associated with a power supply configured
to provide power to a first computer system and a second computer system;
receiving power requirements information associated with the first and second
computer systems;
generating power consumption information using the power requirements information;
providing power consumption information to the first and second computer systems,
wherein power consumption information directs the first and second computer systems
to run with an aggregate power consumption less than the maximum power output,
wherein providing power consumption information comprises sending power consumption
information to a first service processor associated with the first computer system
and to a second service processor associated with the second computer system.
15. The method of claim 14, wherein power requirements information is received
from a user.
16. The method of claim 14, wherein power requirements information is received
from the first and second computer systems.
17. The method of claim 14, wherein the power supply is further configured to
provide power to a third computer system.
18. The method of claim 17, further comprising receiving power requirements information
associated with the third computer system.
19. The method of claim 18, wherein the power supply is further configured to
provide power to the first, second, and third computer systems through a power
distribution network.
20. The method of claim 16, wherein the first and second computer systems each
has its own address space.
21. The method of claim 16, wherein a power authority receives power requirements information.
22. The method of claim 21, wherein power requirements information is received periodically.
23. The method of claim 22, wherein power requirements information is derived
using actual power demands and actual workloads associated with the first and second
computer systems.
24. The method of claim 16, wherein providing power consumption information is
used to adjust power tables associated with the first and second computer systems.
25. The method of claim 24, wherein the power tables are Advanced Configuration
and Power Interface tables.
26. The method of claim 16, wherein power consumption information is provided
before the boot sequence of the first and second computer systems is completed.
27. The method of claim 16, wherein power consumption information is provided
dynamically during runtime of the first and second computer systems.
28. The method of claim 24, wherein adjusting the power table associated with
the first computer system changes the power consumption state of a first component
in the first computer system.
29. A computer readable medium comprising computer code for managing power consumption
across multiple systems, the computer readable medium comprising:
computer code for identifying a maximum power output associated with a power
supply configured to provide power to a first computer system and a second computer system;
computer code for receiving power requirements information associated with the
first and second computer systems;
computer code for generating power consumption information using the power requirements information;
computer code for providing power consumption information to the first and second
computer systems, wherein power consumption information directs the first and second
computer systems to run at specified aggregate power consumption levels, wherein
providing power consumption information comprises sending power consumption information
to a first service processor associated with the first computer system and to a
second service processor associated with the second computer system.
30. The computer readable medium of claim 29, wherein power requirements information
is received from a user.
31. The computer readable medium of claim 29, wherein power requirements information
is received from the first and second computer systems.
32. The computer readable medium of claim 31, wherein the first and second computer
systems each has its own address space.
33. The computer readable medium of claim 31, wherein a power authority receives
power requirements information.
34. The computer readable medium of claim 33, wherein power requirements information
is received periodically.
35. The computer readable medium of claim 34, wherein power requirements information
is derived using actual power demands and actual workloads associated with the
first and second computer systems.
36. The computer readable medium of claim 31, wherein providing power consumption
information is used to adjust power tables associated with the first and second
computer systems.
37. The computer readable medium of claim 36, wherein the power tables are Advanced
Configuration and Power Interface tables.
38. The computer readable medium of claim 31, wherein power consumption information
is provided before the boot sequence of the first and second computer systems is completed.
39. The computer readable medium of claim 31, wherein power consumption information
is provided dynamically during runtime of the first and second computer systems.
40. The computer readable medium of claim 36, wherein adjusting the power table
associated with the first computer system changes the power consumption state of
a first component in the first computer system.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to power management. More specifically,
the present invention provides techniques for statically and dynamically allocating
power across multiple systems to manage individual power demands and meet multiple
system power objectives.
2. Description of Related Art
Limited power management mechanisms are currently available for computer
systems. Conventional mobile computing systems include power management utilities
for setting computer systems into various states of operation based on present
usage levels. In one example, a mobile computing system may be set into a standby
state when the mobile computing system falls into a relatively inactive state of
operation. The standby state can allow increased battery life. However, the different
states of operation can be crude and may not reflect usage patterns of a particular
user. In one example, the mobile system may go into a sleep mode the instant before
processing is scheduled on the unit. Power management on a mobile system is also
limited by what the operating system or BIOS of the mobile system has access to.
Other computing systems have limited power management states. A user can place
a system in a standby state when no work is intended. However, a manual standby
state relies on manual input from a user. Some other systems have components that
will automatically power down into a lower power state when the component has not
been used for a period of time. Again, however, a hard drive may power down right
before a user intends to access a data file and power management is limited to
an individual computing system.
Consequently, it is desirable to provide techniques for improving power
management across systems using both static and dynamic mechanisms for managing
power consumption levels.
SUMMARY OF THE INVENTION
According to the present invention, methods and apparatus are provided
for static and dynamic power management of computer systems. A power authority
manages power usage levels in computer systems by monitoring power consumption
levels and providing power consumption information to the various systems. In one
example, the power authority updates power tables to vary aggregate power consumption levels.
According to various embodiments, an apparatus is provided. The apparatus
includes a plurality of computer systems, a power source, and a power authority.
Each computer system includes a memory coupled to a processor. Each computer system
has a power consumption level, wherein an aggregate power consumption level comprises
a combination of the power consumption levels associated with the plurality of
computer systems. A power source provides power to the plurality of computer systems.
A power authority subsystem manipulates the aggregate power consumption levels
by managing the power consumption levels of the plurality of computer systems.
According to other embodiments, a method for managing power consumption
across multiple systems is provided. The method includes identifying a maximum
power output associated with a power supply configured to provide power to a first
computer system and a second computer system, receiving power requirements information
associated with the first and second computer systems, generating power consumption
information using the power requirements information, and providing power consumption
information to the first and second computer systems, wherein power consumption
information directs the first and second computer systems to run with an aggregate
power consumption less than the maximum power output.
Another aspect of the invention pertains to computer program products including
a machine readable medium on which is stored program instructions, tables or lists,
and/or data structures for implementing a method as described above. Any of the
methods, tables, or data structures of this invention may be represented as program
instructions that can be provided on such computer readable media.
A further understanding of the nature and advantages of the present invention
may
be realized by reference to the remaining portions of the specification and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may best be understood by reference to the following description
taken in conjunction with the accompanying drawings, which are illustrative of
specific embodiments of the present invention.
FIG. 1 is a diagrammatic representation of a system that can use the techniques
of the present invention.
FIG. 2 is a diagrammatic representation showing more detail of a specific computer system.
FIG. 3 is a diagrammatic representation depicting power related components that
can be implemented on a computer system.
FIG. 4 is a diagrammatic representation of a power table.
FIG. 5 is a graphical representation of actual power consumption levels for
various components.
FIG. 6 is a flow process diagram showing an example of static management of
power consumption across multiple systems.
FIG. 7 is a flow process diagram showing an example of dynamic management of
power consumption across multiple systems using an actual power consumption level history.
FIG. 8 is a flow process diagram showing the generation of power consumption information.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
Reference will now be made in detail to some specific embodiments of the
invention including the best modes contemplated by the inventors for carrying out
the invention. Examples of these specific embodiments are illustrated in the accompanying
drawings. While the invention is described in conjunction with these specific embodiments,
it will be understood that it is not intended to limit the invention to the described
embodiments. On the contrary, it is intended to cover alternatives, modifications,
and equivalents as may be included within the spirit and scope of the invention
as defined by the appended claims. Any single or multiple system architecture using
a power source can use the techniques of the present invention. In the following
description, numerous specific details are set forth in order to provide a thorough
understanding of the present invention. The present invention may be practiced
without some or all of these specific details. In other instances, well known process
operations have not been described in detail in order not to unnecessarily obscure
the present invention.
FIG. 1 is a diagrammatic representation of a system that can use the techniques
of the present invention. According to various embodiments, the system is configured
on a rack
101. It should be noted, however, that the techniques of the present
invention can be applied to a configuration having multiple racks. The rack
101
can contain various computer systems such as application server
111, database
server
113, and web server
115. Each computer system can include
multiple processors and multiple storage components. In one example, each computer
system has its own address space. Each computer system is connected to a backplane
149 through backplane interfaces
135,
137, and
139.
The backplane interface allows application server
111, database server
1
13, and web server
115 to communicate with each other as well as
to communicate with an external network
151 through network card
103.
Network card
103 similarly has a backplane interface
131 and a network
interface
143.
It should be noted that each of the computer systems
111,
113,
and
115 may be connected in a variety of different manners. In one example,
backplane
149 can be a SCSI or Ethernet medium. In another example, each
computer system may have direct point-to-point links with other computer systems.
Each computer system may also have its own network card or interface with external
networks. In one implementation, the techniques of the present invention can be
implemented on separate computer systems that are not configured on a rack or chassis.
It should be noted that the separate computer systems can be connected through
conventional network media such as Ethernet, token ring, or wireless interfaces,
although the separate computer systems may share a power source. Any mechanism
for providing power to a computer system is referred to herein as a power source.
A power source may include one or more power supplies. Alternatively, a power source
may be a power distribution mechanism providing power from a utility or generator
to various power supplies on a rack.
According to various embodiments, power supplies are provided in each system
on a rack. Each system
111,
113, and
115 has one or more individual
power supplies. External power such as that provided from a utility or generator
is supplied to the rack through a mechanism such as a power distribution mechanism.
In another implementation, the various computer systems configured on a rack
101
share power from a power supply
119. The power supply
119 is configured
to provide power to the various computer systems in rack
101 and is typically
selected as a power supply based on its capacity to supply power to all computer
systems
111,
113, and
115. Capacity to supply power to all
computer systems may be based on worst-case expected power requirements. In one
example, the worst-case expected power requirement is the level of power drawn
if all computer systems are operating at full power usage. In one example, the
processor may be operating at the highest possible clock speed, the hard drive
may be spinning constantly, component sound cards, video cards, network cards may
all be in active mode. The power supply may be configured to provide a maximum
power output of 2000 watts and each of the three computer systems may have a maximum
power consumption level of 650 watts for an aggregate power consumption level of
1950 watts.
In typical implementations, if an additional processor or hard-drive is added
to each of the three computer systems, maximum power consumption levels can increase
and render the existing power supply potentially inadequate. When a power supply
is even potentially inadequate or has proven inadequate of the past, additional
power supplies are typically added. However, simply adding power supplies can result
in several drawbacks. Even temporarily insufficient power can disrupt optimal system
operation and lead to processing re-initialization. Furthermore, extra power supplies
are added even when they may not be necessary. In one example, the various computer
systems may not be accessing hard disks frequently, and the average total power
consumption level of the three computer systems may be closer to 800 watts. A power
supply with a maximum power output of 2000 watts would be more than adequate for
such a system, yet in conventional implementations, more power supplies would likely
be added if an additional hard disk were added to each system.
According to various embodiments, the techniques of the present invention
provide a power authority
117 connected to a backplane
149 through
a backplane interface
141 to manage power distribution to various computer
systems
111,
113, and
115. The power authority
117
recognizes the amount of power available from power supply
119 and efficiently
allocates available power to application server
111, database server
113,
and web server
115. According to various embodiments, the power management
by the power authority
117 can be static or dynamic. More specifically,
the allocation can be done through user intervention initially or allocation can
be done automatically with intelligent analysis of past or anticipated usage patterns.
For example, the power authority can allocate more power to a business application
server during business hours and more power to an entertainment web server during
evening hours. If another computer system is added to the rack
101, power
authority
117 can reallocate power distribution to the various computer systems.
In typical implementations, application server
111, database server
113,
and web server
115 each may perform their own power management functions.
The power authority can analyze usage patterns associated with the application
server
111, database server
113, and web server
115 and form
a more complete power management scheme using power usage information not only
from the components within a single system but power usage information across different
systems. The power authority benefits from being able to see overall power consumption
levels. An individual application server
111 may recognize that its own
power consumption levels are high and decrease its power consumption accordingly.
However, an application server
111 can not typically recognize that the
power consumption levels of a database server
113 are low, and consequently
the power supply serving both the application server
111 and the database
server
113 can manage the increased power consumption levels on the application
server
111. According to various embodiments, a service processor or multiple
service processors together can be a power authority.
A power authority associated with the system can recognize overall usage patterns.
The power authority has more information enabling it to determine intelligently
what power allocation levels to set for each system. It should be noted that a
power authority can be a separate computer system, a resource on a particular computer
system, or it can be integrated in one of the power managed systems.
FIG. 2 is a diagrammatic representation of one example of a computer system.
Although one particular computer system will be described in detail, it should
be noted that a variety of different computer system configurations may be employed
to implement the techniques of the present invention. In one example, a computer
system may include a single processor and no permanent storage. In another example,
the computer system may include multiple processors, cache coherence controllers,
service processors, multiple arrays of disks, and various network interfaces. Any
number of computer systems can use the techniques of the present invention.
One example of such a computer system is the computer system
200 shown
in FIG. 2. Computer system
200 includes processors
202a-
202d,
a Basic I/O system (BIOS)
204, a memory subsystem comprising memory banks
206a-
206d, point-to-point communication links
208a-
208e
for interconnecting processors
202a-
202d and I/O
switch
210, a cache coherence controller
230, a service processor
212 which communicates with processors
202a-
202d,
a cache coherence controller
230, and an I/O switch
210 via a JTAG
interface represented in FIG. 2 by links
214a-
214f.
I/O switch
210 connects the rest of the system to I/O adapters
216
and
220.
According to various embodiments, the service processor of the present
invention has the intelligence to manipulate power tables associated with a particular
computer system. Any structure or mechanism for maintaining power management information
is referred to herein as a power table. According to one embodiment, the service
processor can also allow a power authority to manage power directly instead of
managing power through an operating system.
The service processor of the present invention can also have the intelligence
to partition system resources according to a previously specified partitioning
schema. The partitioning can be achieved through direct manipulation of routing
tables associated with the system processors by the service processor which is
made possible by the point-to-point communication infrastructure. The routing tables
are used to control and isolate various system resources, the connections between
which are defined therein. The service processor and computer system partitioning
are described in patent application Ser. No. 09/932,456 titled Computer System
Partitioning Using Data Transfer Routing Mechanism, filed on Aug. 16, 2001, the
entirety of which is incorporated by reference for all purposes.
The processors
202a-d are coupled to a cache coherence controller
230 through point-to-point links
232a-d. Any logic or apparatus
that can be used to provide communication between multiple processor clusters while
maintaining cache coherence is referred to herein as a cache coherence controller.
The cache coherence controller
230 can be coupled to cache coherence controllers
associated with other multiprocessor clusters. It should be noted that there can
be more than one cache coherence controller in one cluster. The cache coherence
controller
230 can communicate with both processors
202a-d as
well as remote clusters using a point-to-point protocol.
As noted above, the specific architecture shown in FIG. 2 is merely exemplary
and the embodiments of the present invention are contemplated having different
configurations and resource interconnections. A variety of alternatives for each
of the system resources shown are possible. According to various embodiments, the
techniques of the present invention can be used in any computer system that supports
the ability to set power levels. Although particular embodiments described herein
may include partitioning and a cache coherence controller, it should be noted that
in many implementations, neither partitioning nor a cache coherence controller
may be used.
FIG. 3 is a diagrammatic representation of one example of a power management
scheme within a computer system. A variety of different power management schemes
can be implemented using the techniques of the present invention. One type of power
management scheme such as the Advanced Power Management (APM) scheme, is implemented
primarily using BIOS instructions. BIOS instructions, typically written in read-only
memory, monitor various computer system devices and initiate shutdown and sleep
modes for the various computer system devices. The BIOS instructions also control
when a hardware component should be returned to a working state.
Another type of power management scheme transfers the power management responsibility
from the BIOS to the operating system. Operating system power management schemes,
such as the Advanced Configuration and Power Interface (ACPI), provide that the
operating system itself can control all system and component power states. An ACPI
system can include a portion
330 having system hardware
331 and external
network
333. An operating system portion
310 can include a kernel
311 and operating system power management system code
313. A variety
of different applications
301 can run on top of the operating system
310.
The operating system power management system code
313 can tell the operating
system when various components should be in particular power states. The operating
system portion
310 can also include device drivers
315 for controlling
system hardware
331 as well as an ACPI driver
317 which allows the
operating system to interact with ACPI power management mechanisms.
The ACPI driver can be an operating system program that controls transitions
between various power states, such as active, sleep, and off. The ACPI power management
portion
320 can include registers
321, tables
325, and BIOS
323. More information about ACPI can be found in the Advanced Configuration
and Power Interface Specification version 1.0b and version 2.0, the entirety of
which is incorporated by reference for all purposes. ACPI registers
321
can store and pass information between the ACPI driver
317 and the system
hardware
331. The ACPI tables are used to maintain power management information
such as power supplies, power states, clock sources, features available on various
hardware components, and techniques for managing those features. Any structure
or mechanism for providing power management information is referred to herein as
a power table. In one example, a power table is an ACPI power table.
According to various embodiments, the power authority is an application
running on an operating system. The application receives workload messages from
all operating systems over which it has authority. The application can manage mechanisms
such as the various service processors and the underlying ACPI functionality.
FIG. 4 is a diagrammatic representation of one example of a power table. Although
an ACPI table is shown with specific state and power management information, it
should be noted that a variety of different possible structures can be used to
provide power management related information. In one example, only the three states
of active, sleep, and off are stored along with information indicating when to
transition between the three states. Only power management along a system level
may be provided in one example, and all components transition between the active,
sleep, and off states at the same time. In other embodiments, all hardware devices
have different capabilities. Some devices may have various other states including
active, different levels of sleep, soft off, and true off states.
It should be noted that the power tables among the different systems may also
vary. Some systems may have components that support a number of sleep states while
other systems may support only system level power management. A power authority
can recognize differences between power tables amongst the various systems and
adjust power tables based on capabilities and hardware support.
According to various embodiments, the ACPI table
451 include codes
identifying various states. In ACPI, six system level states are defined: the on
state
41, three different sleep states
413,
415,
417,
a soft off state
419, and an off state
421. ACPI also defines and
allows for a variable number of processor performance states,
431,
433,
and
435 that control the voltage and frequency of individual processors.
The ACPI table can additionally include information about various hardware devices
and the capabilities of the hardware devices
401. In one example, a hard
disk may only have three possible states, while a system has six possible states.
The ACPI table
451 can also include information about the power source
403
and information about the clock sources
407. Hardware component features
405 can also include mechanisms for controlling various hardware components.
According to various embodiments of the present invention, the power authority
external to the particular computer system modifies power management information
by changing power table values. In one example, the power authority alters power
table values so that a particular computer system enters sleep mode more readily.
In another example, the power authority can change table values so that less power
is allocated to a particular set of CPUs during certain time periods.
FIG. 5 is a graphical representation of actual power consumption levels for
various systems. According to various embodiments, the web server
505 consumes
different amounts of power at different times
511 and
513. Here,
the web server
505 consumes more power at time
513. Using historical
information such as past power consumption information, a power authority can determine
when and how much power to allocate to various systems. Any information that can
be acquired or provided to a computer system to alter power usage is referred to
herein as power consumption information. In one example, power consumption information
can include codes for setting a device in the standby state. In another example,
power consumption information can include times at which a system processor should
decrease its processing clock speed and voltage.
According to various embodiments, if an application server
507 typically
consumes less power at time
513 than at time
511, less power can
be allocated daily to application server
507 at time
513 even if
the application server
507 is busy at that particular moment. Less power
can be allocated by the power authority because the power authority can override
the power management capabilities of the application server
507. The power
authority can preemptively allocate less power to the application server at time
513 and more power to the web server
505 at time
513.
Power consumption levels can be reported at various times to a power authority
by an operating system associated with the web server application server. According
to various embodiments, the operating system can maintain a large amount of historical
power consumption information and provide information in its entirety to the power
authority. According to other embodiments, an operating system can provide power
consumption information to a power authority during varying fixed intervals time.
The power authority can then compile the information to create a historical power
consumption representation. In still other embodiments, a service processor associated
with a particular system can report power consumption levels information to a power
authority. A service processor can monitor or simply forward power consumption
levels from an operating system to the power authority.
By using a power consumption level history, a power authority can dynamically
manage power consumption levels. More detail on dynamically managing power consumption
across multiple systems using actual power consumption level histories will be
described below. Static power management is also contemplated. According to various
embodiments, power consumption level histories are not needed to implement static
power management.
FIG. 6 is a flow process diagram showing static power management, according
to a specific embodiment of the present invention. At
601, the maximum power
output from a power supply or a group of power supplies is determined. The maximum
power supply output provides information for the power authority to determine maximum
possible load. At
603, entities such as a power authority can set maximum
power consumption levels for various systems served by the power supply. In one
example, the power authority can allocate 300 watts to an application server, 600
watts to a database server, and 600 watts to a web server. The maximum power consumption
levels may be configured by a user providing power requirements information of
the various systems. Information about how much power each of the various systems
may need is referred to herein as power requirements information. At
605,
power table values such as ACPI values are adjusted in various systems so that
the web server, application server, and database server each will use less than
the allotted amount of power. According to other embodiments, power table values
such as ACPI values are adjusted so that average power consumption levels for each
of different systems can be managed by the power supply. At
607, power can
then be managed by each of the individual operating systems using existing power
management mechanisms such as ACPI.
It should be noted that static management can occur at various times. In one
embodiment,
power requirements information can be entered before a reboot sequence to allow
the power authority to access the information and update power table values before
a computer system is restarted. However, it is also contemplated that the power
authority can receive power requirements information after reboot to allow update
of power table values after a system has been restarted.
FIG. 7 is a flow process diagram showing dynamic power management according
to a specific embodiment of the present invention. At
701, the power authority
receives a trigger for action. In one example, the trigger can be a timer or some
indication that aggregate or total power consumption levels by the various systems
is approaching a percentage of total power supply output. In another example, a
trigger can arise after periodically receiving power consumption information. At
703, the power authority characterizes historical actual power consumption
levels for the various systems served by the power supply. It should be noted that
characterizing historical actual power consumption levels may mean gathering numerical
values sent by an operating system or a service processor and identifying patterns
of usage. Characterizing historical actual power consumption levels may also mean
interpreting a graphical representation provided by service processor.
Various techniques for characterizing historical actual power consumption
levels are contemplated. At
705, it can be determined whether updated power
management mechanisms are needed. In one example, if it is determined that a web
server has been allocated 600 watts but has never used more than 300 watts, some
of the power can be reallocated to a different client/server system. In another
example, it may be determined that all systems should reduce power consumption
levels by 20 percent if the aggregate power consumption levels of all the different
systems has reached total power supply output frequently in the past. At
707,
if updated power management mechanisms are needed, power consumption information
is provided to various systems in order to change power table values or ACPI table
values. Power management can then be performed at
709 with updated power
table values. If no updated power management mechanisms are needed, power management
with existing power table values is performed at
713 and a next trigger
is awaited at
711.
It should be noted that changing power tables or ACPI tables is merely one of
a variety of mechanisms for managing power consumption levels within a system.
According to other embodiments, it is contemplated that the power authority can
shut down individual components such as a hard disk when it is determined that
new power management mechanisms are needed. In another example, rules governing
power management within an operating system can be altered in addition to altering
power table values.
FIG. 8 is a diagrammatic representation showing the generation of power consumption
information. As noted above, power consumption information can be obtained from
a variety of different sources. In one example, a power authority can monitor power
supply output to the various systems on a rack
801. In another example,
a service processor or an operating system can provide power consumption information
to the power authority at
803. At
805, the power authority can determine
optimal power management schemes based on usage patterns or historical power consumption
level information. The power authority can then determine whether they can access
power tables through an operating system
807. If the power authority can
access power tables through the operating system, power consumption information
is sent to the operating system
809. The operating system can then update
power table values at
811. If the power authority cannot access power tables
at
807, power consumption information is sent at
813 to a service
processor associated with the system. The service processor can then update power
table values at
815.
While the invention has been particularly shown and described with reference
to specific embodiments thereof, it will be understood by those skilled in the
art that changes in the form and details of the disclosed embodiments may be made
without departing from the spirit or scope of the invention. For example, embodiments
of the present invention may be employed using various mechanisms for historical
power consumption analysis. In another example, multiple service processors may
be associated with a cluster of processors and a power authority can send power
management information to a selected service processor. In still another example,
a power authority may be separate computer system distinct from the different computer
systems it is managing. However, in one example, the power authority can actually
be part of one of the systems that the power authority manages. Therefore, the
scope of the invention should be determined with reference to the appended claims.
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