Home > Articles

  • Print
  • + Share This
Like this article? We recommend


   cpustat - monitor system behavior using CPU performance

   cpustat -c eventspec [-c eventspec]... [-ntD] [ interval [count]]

   cpustat -h

   The cpustat utility allows CPU performance counters to be
   used to monitor the overall behavior of the CPUs in the system.

   If interval is specified, cpustat samples activity every
   interval seconds, repeating forever. If a count is speci-
   fied, the statistics are repeated count times. If neither
   are specified, an interval of five seconds is used, and
   there is no limit to the number of samples that will be

   The following options are supported:
   -c eventspec
      Specifies a set of events for the CPU performance
      counters to monitor. The syntax of these event specif-
      ication can be determined using the -h option to cause
      the usage message to be generated. The semantics of
      these event specifications can be determined by reading
      the CPU manufacturers documentation for the events.
      See cpc_strtoevent(3CPC) for description of the syntax.

      Multiple -c options may be specified, in which case
      the command cycles between the different event set-
      tings on each sample.

   -D  Enables debug mode.

   -h  Prints an extensive help message on how to use the
      utility and how to program the processor-dependent

   -n  Omits all header output (useful if cpustat is the
      beginning of a pipeline).

   -t  Prints an additional column of processor cycle counts,
      if available on the current architecture.

   A closely related utility, cputrack(1), can be used to moni-
   tor the behavior of individual applications with little or
   no interference from other activities on the system.

   The cpustat utility must be run by the super-user, as there
   is an intrinsic conflict between the use of the CPU perfor-
   mance counters system-wide by cpustat and the use of the CPU
   performance counters to monitor an individual process (for
   example, by cputrack.)

   Once any instance of this utility has started, no further
   per-process or per-LWP use of the counters is allowed until
   the last instance of the utility terminates.

   The times printed by the command correspond to the wallclock
   time when the hardware counters were actually sampled,
   instead of when the program told the kernel to sample them.
   The time is derived from the same timebase as gethrtime(3C).

   The processor cycle counts enabled by the -t option always
   apply to both user and system modes, regardless of the set-
   tings applied to the performance counter registers.

   On some hardware platforms, the counters are implemented
   using 32-bit registers. While the kernel attempts to catch
   all overflows to synthesize 64-bit counters, because of
   hardware implementation restrictions, overflows may be lost
   unless the sampling interval is kept short enough. The
   events most prone to wrap are those that count processor
   clock cycles. If such an event is of interest, sampling
   should occur frequently so that less than 4 billion clock
   cycles can occur between samples.

The output of cpustat is designed to be readily parseable by
   nawk(1) and perl(1), thereby allowing performance tools to
   be composed by embedding cpustat in scripts. Alternatively,
   tools may be constructed directly using the same APIs that
   cpustat is built upon using the facilities of libcpc(3LIB).
   See cpc(3CPC).

   The cpustat utility only monitors the CPUs that are accessi-
   ble to it in the current processor set. Thus, several
   instances of the utility can be running on the CPUs in dif-
   ferent processor sets. See psrset(1M) for more information
   about processor sets.

Because cpustat uses LWPs bound to CPUs, the utility may
   have to be terminated before the configuration of the
   relevant processor can be changed.
   By running the cpustat command, the super-user will forcibly
   invalidate all existing performance counter context. This
   may in turn cause all invocations of the cputrack command,
   and other users of performance counter context, to exit
   prematurely with unspecified errors.

   If cpustat is invoked on a system that has CPU performance
   counters, but on which the packages containing the kernel
   support for those counters is not installed, the following
   message appears:

   cpustat: CPU performance counters are inaccessible on this

   This error message implies that cpc_access() has failed and
   is documented in cpc_access(3CPC). Review this documentation
   for more information about the problem and possible solu-

   See attributes(5) for descriptions of the following attri-

  | Availability        | SUNWcpcu          |
  | Interface Stability     | Evolving          |

   cputrack(1), nawk(1), perl(1),  iostat(1M),  prstat(1M),
   psrset(1M),  vmstat(1M),  cpc(3CPC),  cpc_access(3CPC),
   cpc_strtoevent(3CPC), gethrtime(3C), libcpc(3LIB), attri-

   Sun Microelectronics UltraSPARC I&II User's Manual, January
   1997, STP1031, http://www.sun.com/sparc

   Intel Architecture Software Developer's Manual, Volume 3:
   System Programmers Guide, 243192, http://developer.intel.com
  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020