[lkml]   [2011]   [Oct]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: A Plumber’s Wish List for Linux
On Fri, Oct 14, 2011 at 8:38 AM, Frederic Weisbecker <> wrote:
> Well, wouldn't it be better to pull that complexity to userspace?
> After all, moving tasks from a cgroup to another is not a performance
> critical operation so that probably doesn't need to be all handled by
> the kernel.

I'd always assumed that too, but apparently on very many (possibly the
majority of?) Linux systems, it actually is performance-critical.

Specifically, Android bounces tasks in and out of a "foreground
low-latency" cpu cgroup at a fairly high rate, and has found the
performance hit from the locking to be a problem on multi-core phones.
Hence Colin Cross' patches for avoid calls to synchronize_rcu() in the
attach path.


 \ /
  Last update: 2011-10-19 23:23    [W:0.110 / U:2.076 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site