DEV Community

yuyabu
yuyabu

Posted on

6 1

gnu time(usr/bin/time) can check process memory usage,without vmstat or sar

There are two types of time commands.

  • bash built-in time command
  • gnu time

The gnu time command can measure cpu usage, average memory usage, maximum memory usage, etc.
Although the default output format is hard to see, users can define their own format and select only the necessary information.

Environmental information

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Ubuntu 18.04.2 LTS"
FORMATTING THE OUTPUT  

| %  | A literal `%'.                                                                                                                                                                                                                                 | 
|----|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| 
| C  | Name and command line arguments of the command being timed.                                                                                                                                                                                    | 
| D  | Average size of the process's unshared data area, in Kilobytes.                                                                                                                                                                                | 
| E  | Elapsed real (wall clock) time used by the process, in [hours:]minutes:seconds.                                                                                                                                                                | 
| F  | Number of major, or I/O-requiring, page faults that occurred while the process was running.  These are faults where the page has actually migrated out of primary memory.                                                                      | 
| I  | Number of file system inputs by the process.                                                                                                                                                                                                   | 
| K  | Average total (data+stack+text) memory use of the process, in Kilobytes.                                                                                                                                                                       | 
| M  | Maximum resident set size of the process during its lifetime, in Kilobytes.                                                                                                                                                                    | 
| O  | Number of file system outputs by the process.                                                                                                                                                                                                  | 
| P  | Percentage of the CPU that this job got.  This is just user + system times divided by the total running time.  It also prints a percentage sign.                                                                                               | 
| R  | Number of minor, or recoverable, page faults.  These are pages that are not valid (so they fault) but which have not yet been claimed by other virtual pages.  Thus the data in the page is still valid but the system tables must be updated. | 
| S  | Total number of CPU-seconds used by the system on behalf of the process (in kernel mode), in seconds.                                                                                                                                          | 
| U  | Total number of CPU-seconds that the process used directly (in user mode), in seconds.                                                                                                                                                         | 
| W  | Number of times the process was swapped out of main memory.                                                                                                                                                                                    | 
| X  | Average amount of shared text in the process, in Kilobytes.                                                                                                                                                                                    | 
| Z  | System's page size, in bytes.  This is a per-system constant, but varies between systems.                                                                                                                                                      | 
| c  | Number of times the process was context-switched involuntarily (because the time slice expired).                                                                                                                                               | 
| e  | Elapsed real (wall clock) time used by the process, in seconds.                                                                                                                                                                                | 
| k  | Number of signals delivered to the process.                                                                                                                                                                                                    | 
| p  | Average unshared stack size of the process, in Kilobytes.                                                                                                                                                                                      | 
| r  | Number of socket messages received by the process.                                                                                                                                                                                             | 
| s  | Number of socket messages sent by the process.                                                                                                                                                                                                 | 
| t  | Average resident set size of the process, in Kilobytes.                                                                                                                                                                                        | 
| w  | Number of times that the program was context-switched voluntarily, for instance while waiting for an I/O operation to complete.                                                                                                                | 
| x  | Exit status of the command.                                                                                                                                                                                                                    
(this table from manpage of  time)

You can register the format in the environment variable $ TIME or specify the format with -f option.

export TIME="time result\ncmd:%C\nreal %es\nuser %Us \nsys  %Ss \nmemory:%MKB \ncpu %P"

or

time -f "time result\ncmd:%C\nreal %es\nuser %Us \nsys  %Ss \nmemory:%MKB \ncpu %P" <command>

Execution result (running and check sleep command)

$ /usr/bin/time sleep 1
time result
cmd:sleep 1
real 1.00s
user 0.00s 
sys  0.00s 
memory:2128KB 
cpu 0%

Image of Timescale

🚀 pgai Vectorizer: SQLAlchemy and LiteLLM Make Vector Search Simple

We built pgai Vectorizer to simplify embedding management for AI applications—without needing a separate database or complex infrastructure. Since launch, developers have created over 3,000 vectorizers on Timescale Cloud, with many more self-hosted.

Read full post →

Top comments (2)

Collapse
 
jrwren profile image
Jay R. Wren •

time(2) is the syscall. time_t time(time_t *tloc)

gnu time is /usr/bin/time

Collapse
 
yuyabu profile image
yuyabu •

thank you for your advice.
I rewrite title.

Billboard image

The Next Generation Developer Platform

Coherence is the first Platform-as-a-Service you can control. Unlike "black-box" platforms that are opinionated about the infra you can deploy, Coherence is powered by CNC, the open-source IaC framework, which offers limitless customization.

Learn more

đź‘‹ Kindness is contagious

Please leave a ❤️ or a friendly comment on this post if you found it helpful!

Okay