how to find number of threads in a process on linux ?

The proc pseudo file system, which resides in /proc directory, is the easiest way to see the thread count of any active process. The /proc directory exports in the form of readable text files a wealth of information related to existing processes and system hardware such as CPU, interrupts, memory, disk, etc.

cat /proc/<pid>/status

The proc pseudo file system, which resides in /proc directory, is the easiest way to see the thread count of any active process. The /proc directory exports in the form of readable text files a wealth of information related to existing processes and system hardware such as CPU, interrupts, memory, disk, etc.

Threads: <N>

For example Find the pid of the google chrome and find the each process using how many Threads.

root@linuxforfreshers.com:~# ps -ef | grep chrome

root      28168 20969  1 15:45 ?        00:00:17 /opt/google/chrome/chrome

Where 28168 is pid of google chrmoe.

Or

root@linuxforfreshers.com:~# pidof chrome

28168

Example :

root@linuxforfreshers.com:~# cat /proc/28168/status

Name: chrome

State:   S (sleeping)

Tgid:    28168

Ngid:    0

Pid:      28168

PPid:    20969

TracerPid:       0

Uid:      1000    1000    1000    1000

Gid:      1000    1000    1000    1000

FDSize: 256

Groups:            4 24 27 30 46 108 124 128 1000

NStgid: 28168  12008  1

NSpid:  28168  12008  1

NSpgid:            3938    0          0

NSsid:  3938    0          0

VmPeak:          1087572 kB

VmSize:           1028908 kB

VmLck:                   0 kB

VmPin:        0 kB

VmHWM:          311332 kB

VmRSS:              212288 kB

VmData:            606664 kB

VmStk:      136 kB

VmExe:              109204 kB

VmLib:    45784 kB

VmPTE:                1676 kB

VmPMD:               620 kB

VmSwap:             8520 kB

HugetlbPages:        0 kB

Threads:          15

SigQ:    0/15451

SigPnd:            0000000000000000

ShdPnd:           0000000000000000

SigBlk: 0000000000000000

SigIgn: 0000000000001002

SigCgt: 00000001c0014efd

CapInh:            0000000000000000

CapPrm:          0000000000000000

CapEff:            0000000000000000

CapBnd:           0000003fffffffff

CapAmb:         0000000000000000

Seccomp:         2

Cpus_allowed: 3

Cpus_allowed_list:      0-1

Mems_allowed:          00000000,00000001

Mems_allowed_list:   0

voluntary_ctxt_switches:        32357

nonvoluntary_ctxt_switches:  18926

Or

root@linuxforfreshers.com:~# cat /proc/28168/status | grep Threads

Threads:          15

Method 2: Using ls command

syntax:

ls /proc/<pid>/task | wc -l

This is because, for every thread created within a process, there is a corresponding directory created in /proc/<pid>/task, named with its thread ID. Thus the total number of directories in /proc/<pid>/task represents the number of threads in the process.

Example:

root@linuxforfreshers.com:~# ls /proc/28168/task/ | wc -l

15

Method 3: Using ps command

Syntax:

ps huH p <PID_OF_U_PROCESS> | wc -l

Example :

root@linuxforfreshers.com:~# ps huH p 28168 | wc -l

15

Method 4:

Syntax: ps -eT | grep <PID_of_process> | wc -l

Example :

root@linuxforfreshers.com:~# ps -eT | grep 28168 | wc -l

15