[PATCH 1/7] cgroup: cgroup_subsys->fork() should be called after the task is added to css_set
tj at kernel.org
Wed Oct 24 19:04:58 UTC 2012
On Tue, Oct 23, 2012 at 05:51:28PM +0200, Oleg Nesterov wrote:
> Yes, yes. But in this case (I mean, for uprobes) "threadgroup" in the name
> is misleading. It should be called unconditially without any argument.
> Please see
> [PATCH 1/2] brw_mutex: big read-write mutex
Ooh... that's something completely different.
> [PATCH 2/2] uprobes: Use brw_mutex to fix register/unregister vs dup_mmap() race
> for details, but in short 2/2 needs this giant lock to block dup_mmap()
> system-wide, while cgroup (currently) only needs threadgroup lock if
> CLONE_THREAD (ignoring do_exit) and per-task.
> So please forget, I no longer think it makes sense to use the same
> thing for uprobes and cgroups.
It is quite tempting to reduce hot path overhead and penalize cgroup
migration ops more tho. Write-locking brw_mutex on migration might
not be too bad. Why did you change your mind?
More information about the Containers