linux-kernel - Re: A question about group CFS scheduling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ac8af0be0806260133u68a5692flab65e4bb6dcf2a13@mail.gmail.com>
Date:	Thu, 26 Jun 2008 16:33:11 +0800
From:	"Zhao Forrest" <forrest.zhao@...il.com>
To:	"Peter Zijlstra" <peterz@...radead.org>
Cc:	vatsa@...ux.vnet.ibm.com, mingo@...e.hu, containers@...ts.osdl.org,
	linux-kernel@...r.kernel.org
Subject: Re: A question about group CFS scheduling

>
> Let me explain the cgroup case (the sanest option IMHO):
>
> initially all your tasks will belong to the root cgroup, eg:
>
> assuming:
> mkdir -p /cgroup/cpu
> mount none /cgroup/cpu -t cgroup -o cpu
>
> Then the root cgroup (cgroup:/) is /cgroup/cpu/ and all tasks will be
> found in /cgroup/cpu/tasks.
>
> You can then create new groups as sibling from this root group, eg:
>
> cgroup:/foo
> cgroup:/bar
>
> They will get a weigth of 1024 by default, exactly as heavy as a nice 0
> task.
>
> That means that no matter how many tasks you stuff into foo, their
> combined cpu time will be as much as a single tasks in cgroup:/ would
> get.
>
> This is fully recursive, so you can also create:
>
> cgroup:/foo/bar and its tasks in turn will get as much combined cpu time
> as a single task in cgroup:/foo would get.
>
> In theory this should go on indefinitely, in practise we'll run into
> serious numerical issues quite quickly.
>
>
> The USER grouping basically creates a fake root and all uids (including
> 0) are its siblings. The only special case is that uid-0 (aka root) will
> get twice the weight of the others.
>

Thank you for your detailed explanation! I have one more question:
cgrouping and USER grouping is mutual exclusive, am I right? That is,
when enabling cgrouping, USER grouping need to be disabled, vice
versa.

Thanks,
Forrest
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/