Posted Jun 1, 2007 14:33 UTC (Fri) by IkeTo
In reply to: Process containers
Parent article: Process containers
> Process group lists have always been a light-weight set of properties that
> processes carry around and pass on through fork().
Can you clarify a little bit? AFAIK, there are two concepts of "groups" in the current kernel. One is called the "process group", as is set by setpgid(). Each process belong to one group (rather than many). That group is used for signal deliveries, allowing users to send signals to all processes of a group, either by explicit "kill" command/system call, or by using a special terminal character. The other is the "supplementary group IDs", as is set by setgroups(). Each process has a small number of those. It is used by system administrators to control the files or other resources that each user can access. The numeric values are meaningful not only to the kernel, but to the admin as well. They assign each user a list of such group IDs in /etc/group, and the login procedure will assign the login shell (or X session) process to use that list. There is also the session ID, but that doesn't seem like being what you mean.
So by "process group" do you mean one of these existing concepts, or is there yet another group concept in the process carried by the process that either is hidden in the kernel or that I forgot?
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