Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH v4] sched: automated per session task groups | From | Peter Zijlstra <> | Date | Tue, 30 Nov 2010 14:48:07 +0100 |
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On Tue, 2010-11-30 at 14:18 +0100, Mike Galbraith wrote: > > From: Mike Galbraith <efault@gmx.de> > Date: Tue Nov 30 14:07:12 CET 2010 > Subject: [PATCH] sched: Improve desktop interactivity: Implement automated per session task groups > > A recurring complaint from CFS users is that parallel kbuild has a negative > impact on desktop interactivity. This patch implements an idea from Linus, > to automatically create task groups. Currently, only per session autogroups > are implemented, but the patch leaves the way open for enhancement. > > Implementation: each task's signal struct contains an inherited pointer to > a refcounted autogroup struct containing a task group pointer, the default > for all tasks pointing to the init_task_group. When a task calls setsid(), > a new task group is created, the process is moved into the new task group, > and a reference to the preveious task group is dropped. Child processes > inherit this task group thereafter, and increase it's refcount. When the > last thread of a process exits, the process's reference is dropped, such > that when the last process referencing an autogroup exits, the autogroup > is destroyed. > > At runqueue selection time, IFF a task has no cgroup assignment, its current > autogroup is used. > > Autogroup bandwidth is controllable via setting it's nice level through the > proc filesystem. cat /proc/<pid>/autogroup displays the task's group and the > group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task > group's shares to the weight of nice <level> task. Setting nice level is rate > limited for !admin users due to the abuse risk of task group locking. > > The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is > selected, but can be disabled via the boot option noautogroup, and can also > be turned on/off on the fly via.. > echo [01] > /proc/sys/kernel/sched_autogroup_enabled. > ..which will automatically move tasks to/from the root task group. > > Signed-off-by: Mike Galbraith <efault@gmx.de> > Cc: Oleg Nesterov <oleg@redhat.com> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Markus Trippelsdorf <markus@trippelsdorf.de> > Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> > Signed-off-by: Ingo Molnar <mingo@elte.hu>
Looks good to me, Thanks Mike!
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
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