Gwan - 为什么gwan只确定1个核心?

时间:2013-05-22 07:03:58

标签: multicore g-wan hypervisor

我目前正在测试gwan Web服务器,我对gwan worker的默认设置和CPU Core检测有疑问。

在Xen服务器(包含4核Xeon CPU)上运行gwan,gwan.log文件报告只检测到单个核心:

'./gwan -w 4' used to override 1 x 1-Core CPU(s)
[Wed May 22 06:54:29 2013 GMT]   using   1 workers 0[01]0
[Wed May 22 06:54:29 2013 GMT]   among   2 threads 0[11]1
[Wed May 22 06:54:29 2013 GMT]   (can't use more threads than CPU Cores)

[Wed May 22 06:54:29 2013 GMT] CPU: 1x Intel(R) Xeon(R) CPU E5506 @ 2.13GHz
[Wed May 22 06:54:29 2013 GMT]  0 id: 0     0
[Wed May 22 06:54:29 2013 GMT]  1 id: 1     1
[Wed May 22 06:54:29 2013 GMT]  2 id: 2     2
[Wed May 22 06:54:29 2013 GMT]  3 id: 3     3
[Wed May 22 06:54:29 2013 GMT] CPU(s):1, Core(s)/CPU:1, Thread(s)/Core:2

有什么想法吗?

谢谢!

1 个答案:

答案 0 :(得分:1)

  

gwan.log文件报告我只有一个核心:

与许多其他虚拟机管理程序一样,

Xen正在破坏CPUID指令和/proc/cpuinfo Linux内核结构(G-WAN都使用它们来检测CPU内核)。 / p>

正如您所看到的,对于旨在扩展多核的多线程应用程序来说,这是一个真正的问题。

  

'./ gwan -w 4'用于覆盖1 x 1-Core CPU

为避免愚蠢的手动覆盖浪费内存并影响性能,G-WAN会检查用户提供的线程数是否大于实际CPU核心数。

这就是为什么你有警告:“(不能使用比CPU内核更多的线程)”

要绕过此保护和警告,您可以使用-g(“上帝”)模式:

./gwan -g -w 4

此命令行开关记录在G-WAN可执行文件帮助中:

./gwan -h

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Usage: gwan [-b -d -g -k -r -t -v -w] [argument]
(grouped options '-bd' are ignored, use '-b -d')

  -b: use the TCP_DEFER_ACCEPT TCP option
      (this is disabling the DoS shield!)

  -d: daemon mode (uses an 'angel' process)
      -d:group:user dumps 'root' privileges

  -g: do not limit worker threads to Cores
      (using more threads than physical Cores
       will lower speed and waste resources)

  -k: (gracefully) kill local gwan processes
      using the pid files of the gwan folder

  -r: run the specified C script (and exit)
      for general-purpose code, not servlets

  -t: store client requests in 'trace' file
      (may be useful to debug/trace attacks)

  -v: return version number and build date

  -w: define the number of worker threads.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Available network interfaces (2):
127.0.0.1 192.168.0.11