如何知道Puma中的活动线程数 [英] How to know the number of active threads in Puma
问题描述
我正在尝试查看服务器上活动的puma线程的数量.
I am trying to see the number of active puma threads on my server.
我无法通过ps看到它:
$ ps aux | grep puma
healthd 2623 0.0 1.8 683168 37700 ? Ssl May02 5:38 puma 2.11.1 (tcp://127.0.0.1:22221) [healthd]
root 8029 0.0 0.1 110460 2184 pts/0 S+ 06:34 0:00 grep --color=auto puma
root 18084 0.0 0.1 56836 2664 ? Ss May05 0:00 su -s /bin/bash -c puma -C /opt/elasticbeanstalk/support/conf/pumaconf.rb webapp
webapp 18113 0.0 0.8 83280 17324 ? Ssl May05 0:04 puma 2.16.0 (unix:///var/run/puma/my_app.sock) [/]
webapp 18116 3.5 6.2 784992 128924 ? Sl May05 182:35 puma: cluster worker 0: 18113 [/]
在配置中，我有:
threads 8, 32
我期望看到至少8个彪马线吗?
I was expecting to see at least 8 puma threads?
推荐答案
要快速回答该问题， 可以使用 以下:
To quickly answer the question, the number of threads used by a process running on a given PID, can be obtained using the following :
% ps -h -o nlwp <pid>
这只会返回您使用的线程总数
过程.选项-h删除标题，而选项-o nlwp
格式化ps的输出，使其仅输出轻量进程数(NLWP)或线程.例如，当仅运行单个进程puma并且使用pgrep获取其PID时，您将得到:
This will just return you the total number of threads used by the
process. The option -h removes the headers and the option -o nlwp
formats the output of ps such that it only outputs the Number of Light Weight Processes (NLWP) or threads. Example, when only a single process puma is running and its PID is obtained with pgrep, you get:
% ps -h -o nlwp $(pgrep puma)
4
进程，线程进程和轻量级进程之间有什么区别?
这个问题已经在各个地方得到了回答 [请参见此处，
This question has been answered already in various places [See here, here and the excellent geekstuff article]. The quick, short and ugly version is :
-
进程本质上是程序的任何运行实例.
a process is essentially any running instance of a program.
线程是该过程的执行流程.一个过程
包含多个执行流的过程称为多线程
处理并在线程之间共享资源(内存，
打开文件，io，...). Linux内核不知道什么
threads是并且仅知道进程.在过去，
多线程是在用户级别而不是内核上处理的
等级.这使得内核很难进行适当的处理
管理.
a thread is a flow of execution of the process. A process
containing multiple execution-flows is known as multi-threaded
process and shares its resources amongst its threads (memory,
open files, io, ...). The Linux kernel has no knowledge of what
threads are and only knows processes. In the past,
multi-threading was handled on a user level and not kernel
level. This made it hard for the kernel to do proper process
management.
输入轻量级进程(LWP).这本质上是 回答线程问题.每个线程都被认为是 在内核级别成为LWP.之间的主要区别 流程和LWP是LWP共享资源.换句话说，轻量级进程代表了用户所说的 thread 线程.
Enter lightweight processes (LWP). This is essentially the answer to the issue with threads. Each thread is considered to be an LWP on kernel level. The main difference between a process and an LWP is that the LWP shares resources. In other words, an Light Weight Process is kernel-speak for what users call a thread.
ps可以显示有关线程或LWP的信息吗?
Can ps show information about threads or LWP's?
ps命令或进程状态命令提供信息
关于当前正在运行的进程，包括它们对应的
LWP或线程.为此，它使用/proc目录
这是一个虚拟文件系统，被视为控件和
内核信息中心. [请参见此处和
The ps command or process status command provides information
about the currently running processes including their corresponding
LWPs or threads. To do this, it makes use of the /proc directory
which is a virtual filesystem and regarded as the control and
information centre of the kernel. [See here and here].
默认情况下，ps不会为您提供有关LWP的任何信息，
但是，通常在命令中添加选项-L和-m
诀窍.
By default ps will not give you any information about the LWPs,
however, adding the option -L and -m to the command generally does
the trick.
man ps :: THREAD DISPLAY
man ps :: THREAD DISPLAY
H Show threads as if they were processes.
-L Show threads, possibly with LWP and NLWP columns.
m Show threads after processes.
-m Show threads after processes.
-T Show threads, possibly with SPID column.
对于具有pgrep puma
% ps -fL $(pgrep puma)
UID PID PPID LWP C NLWP STIME TTY STAT TIME CMD
kvantour 2160 2876 2160 0 4 15:22 pts/39 Sl+ 0:00 ./puma
kvantour 2160 2876 2161 99 4 15:22 pts/39 Rl+ 0:14 ./puma
kvantour 2160 2876 2162 99 4 15:22 pts/39 Rl+ 0:14 ./puma
kvantour 2160 2876 2163 99 4 15:22 pts/39 Rl+ 0:14 ./puma
但是，添加-m选项显然可以提供更好的概述.这
当多个进程同时运行时特别方便
名称.
however, adding the -m option clearly gives a nicer overview. This
is especially handy when multiple processes are running with the same
name.
% ps -fmL $(pgrep puma)
UID PID PPID LWP C NLWP STIME TTY STAT TIME CMD
kvantour 2160 2876 - 0 4 15:22 pts/39 - 0:44 ./puma
kvantour - - 2160 0 - 15:22 - Sl+ 0:00 -
kvantour - - 2161 99 - 15:22 - Rl+ 0:14 -
kvantour - - 2162 99 - 15:22 - Rl+ 0:14 -
kvantour - - 2163 99 - 15:22 - Rl+ 0:14 -
在此示例中，您看到带有PID 2160的进程puma运行4
ID为2160--2163的线程(NLWP).在STAT下，您看到两个不同的值Sl+和'Rl +'. l是multi-threaded的指示器. S和R代表可中断睡眠(等待事件完成)和运行中.因此，我们看到4个线程中的3个正在以99％的CPU运行，而一个线程正在休眠.
您还会看到总的累计CPU时间(44秒)，而一个线程仅运行14秒.
In this example, you see that process puma with PID 2160 runs with 4
threads (NLWP) having the ID's 2160--2163. Under STAT you see two different values Sl+ and 'Rl+'. Here the l is an indicator for multi-threaded. S and R stand for interruptible sleep (waiting for an event to complete) and respectively running. So we see that 3 of the 4 threads are running at 99% CPU and one thread is sleeping.
You also see the total accumulated CPU time (44s) while a single thread only runs for 14s.
获取信息的另一种方法是直接使用格式
-o或-O的指定符.
Another way to obtain information is by directly using the format
specifiers with -o or -O.
man ps :: STANDARD FORMAT SPECIFIERS
man ps :: STANDARD FORMAT SPECIFIERS
lwp lightweight process (thread) ID of the dispatchable
entity (alias spid, tid). See tid for additional
information. Show threads as if they were processes.
nlwp number of lwps (threads) in the process. (alias thcount).
因此您可以使用lwp，spid或tid和nlwp或thcount中的任何一个.
So you can use any of lwp,spid or tid and nlwp or thcount.
如果您只想获取称为的进程的线程数
puma，您可以使用:
If you only want to get the number of threads of a process called
puma, you can use :
% ps -o nlwp $(pgrep puma)
NLWP
4
或者如果您不喜欢标题
% ps -h -o nlwp $(pgrep puma)
4
您可以通过:
% ps -O nlwp $(pgrep puma)
PID NLWP S TTY TIME COMMAND
19304 4 T pts/39 00:00:00 ./puma
最后，您可以将标志与ps aux组合以列出线程.
Finally, you can combine the flags with ps aux to list the threads.
% ps aux -L
USER PID LWP %CPU NLWP %MEM VSZ RSS TTY STAT START TIME COMMAND
...
kvantour 1618 1618 0.0 4 0.0 33260 1436 pts/39 Sl+ 15:17 0:00 ./puma
kvantour 1618 1619 99.8 4 0.0 33260 1436 pts/39 Rl+ 15:17 0:14 ./puma
kvantour 1618 1620 99.8 4 0.0 33260 1436 pts/39 Rl+ 15:17 0:14 ./puma
kvantour 1618 1621 99.8 4 0.0 33260 1436 pts/39 Rl+ 15:17 0:14 ./puma
...
top可以显示有关线程或LWP的信息吗?
Can top show information about threads or LWP's?
top可以选择通过以下方式显示线程:通过在交互模式下单击H或通过使用top -H启动top.问题在于它将线程列为进程(类似于ps -fH).
top has the option to show threads by hitting H in the interactive mode or by launching top with top -H. The problem is that it lists the threads as processes (similar to ps -fH).
% top
top - 09:42:10 up 17 days, 3 min, 1 user, load average: 3.35, 3.33, 2.75
Tasks: 353 total, 3 running, 347 sleeping, 3 stopped, 0 zombie
%Cpu(s): 75.5 us, 0.6 sy, 0.5 ni, 22.6 id, 0.0 wa, 0.0 hi, 0.8 si, 0.0 st
KiB Mem : 16310772 total, 8082152 free, 3662436 used, 4566184 buff/cache
KiB Swap: 4194300 total, 4194300 free, 0 used. 11363832 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
868 kvantour 20 0 33268 1436 1308 S 299.7 0.0 46:16.22 puma
1163 root 20 0 920488 282524 258436 S 2.0 1.7 124:48.32 Xorg
...
在这里您看到puma在大约300％的CPU上运行，累积时间为46:16.22.但是，没有迹象表明这是一个线程进程.唯一的指标是CPU使用率，但是，如果3个线程在睡眠"状态，则可能低于100％?此外，状态标志状态S，该状态指示第一线程处于睡眠状态.击中H会给你
Here you see that puma runs at about 300% CPU for an accumulated time of 46:16.22. There is, however, no indicator that this is a threaded process. The only indicator is the CPU usage, however, this could be below 100% if 3 threads are "sleeping"? Furthermore, the status flag states S which indicates that the first thread is asleep. Hitting H give you then
% top -H
top - 09:48:30 up 17 days, 10 min, 1 user, load average: 3.18, 3.44, 3.02
Threads: 918 total, 5 running, 910 sleeping, 3 stopped, 0 zombie
%Cpu(s): 75.6 us, 0.2 sy, 0.1 ni, 23.9 id, 0.0 wa, 0.0 hi, 0.2 si, 0.0 st
KiB Mem : 16310772 total, 8062296 free, 3696164 used, 4552312 buff/cache
KiB Swap: 4194300 total, 4194300 free, 0 used. 11345440 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
870 kvantour 20 0 33268 1436 1308 R 99.9 0.0 21:45.35 puma
869 kvantour 20 0 33268 1436 1308 R 99.7 0.0 21:45.43 puma
872 kvantour 20 0 33268 1436 1308 R 99.7 0.0 21:45.31 puma
1163 root 20 0 920552 282288 258200 R 2.0 1.7 124:52.05 Xorg
...
现在我们只看到3个线程.由于其中一个线程处于睡眠状态"，因此它按top按CPU使用率排序的方式一直处于最低水平.
Now we see only 3 threads. As one of the Threads is "sleeping", it is way down the bottom as top sorts by CPU usage.
为了查看所有线程，最好让top显示特定的pid(对于单个进程):
In order to see all threads, it is best to ask top to display a specific pid (for a single process):
% top -H -p $(pgrep puma)
top - 09:52:48 up 17 days, 14 min, 1 user, load average: 3.31, 3.38, 3.10
Threads: 4 total, 3 running, 1 sleeping, 0 stopped, 0 zombie
%Cpu(s): 75.5 us, 0.1 sy, 0.2 ni, 23.6 id, 0.0 wa, 0.0 hi, 0.7 si, 0.0 st
KiB Mem : 16310772 total, 8041048 free, 3706460 used, 4563264 buff/cache
KiB Swap: 4194300 total, 4194300 free, 0 used. 11325008 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
869 kvantour 20 0 33268 1436 1308 R 99.9 0.0 26:03.37 puma
870 kvantour 20 0 33268 1436 1308 R 99.9 0.0 26:03.30 puma
872 kvantour 20 0 33268 1436 1308 R 99.9 0.0 26:03.22 puma
868 kvantour 20 0 33268 1436 1308 S 0.0 0.0 0:00.00 puma
当有多个进程正在运行时，您可能有兴趣点击f并打开PGRP.这显示了过程的组PID. (以ps为单位的PID，顶部的PID是以ps为单位的LWP).
When you have multiple processes running, you might be interested in hitting f and toggle PGRP on. This shows the Group PID of the process. (PID in ps where PID in top is LWP in ps).
如何在不使用ps或top的情况下获取线程计数?
How do I get the thread count without using ps or top?
文件/proc/$PID/status包含一行，说明有多少个线程
PID $PID的进程正在使用.
The file /proc/$PID/status contains a line stating how many threads
the process with PID $PID is using.
% grep Threads /proc/19304/status
Threads: 4
一般评论
- It is possible that you do not find the process of another user
and therefore cannot get the number of threads that process is using. This could be due to the mount options of
/proc/(hidepid=2).
使用的示例程序:
#include <omp.h>
#include <stdio.h>
#include <stdlib.h>
int main (int argc, char *argv[]) {
char c = 0;
#pragma omp parallel shared(c) {
int i = 0;
if (omp_get_thread_num() == 0) {
printf("Read character from input : ");
c = getchar();
} else {
while (c == 0) i++;
printf("Total sum is on thread %d : %d\n", omp_get_thread_num(), i);
}
}
}
用gcc -o puma --openmp
这篇关于如何知道Puma中的活动线程数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
