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  1. 19 2月, 2013 4 次提交
  3. 25 1月, 2013 7 次提交
  5. 23 1月, 2013 1 次提交
    • L
      cgroup: fix bogus kernel warnings when cgroup_create() failed · 2739d3cc
      由 Li Zefan 提交于 
      If cgroup_create() failed and cgroup_destroy_locked() is called to
do cleanup, we'll see a bunch of warnings:

cgroup_addrm_files: failed to remove 2MB.limit_in_bytes, err=-2
cgroup_addrm_files: failed to remove 2MB.usage_in_bytes, err=-2
cgroup_addrm_files: failed to remove 2MB.max_usage_in_bytes, err=-2
cgroup_addrm_files: failed to remove 2MB.failcnt, err=-2
cgroup_addrm_files: failed to remove prioidx, err=-2
cgroup_addrm_files: failed to remove ifpriomap, err=-2
...

We failed to remove those files, because cgroup_create() has failed
before creating those cgroup files.

To fix this, we simply don't warn if cgroup_rm_file() can't find the
cft entry.
Signed-off-by: NLi Zefan <lizefan@huawei.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
      2739d3cc
  7. 15 1月, 2013 2 次提交
    • L
      cgroup: remove synchronize_rcu() from rebind_subsystems() · 130e3695
      由 Li Zefan 提交于 
      Nothing's protected by RCU in rebind_subsystems(), and I can't think
of a reason why it is needed.
Signed-off-by: NLi Zefan <lizefan@huawei.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
      130e3695
    • L
      cgroup: remove synchronize_rcu() from cgroup_attach_{task|proc}() · 5d65bc0c
      由 Li Zefan 提交于 
      These 2 syncronize_rcu()s make attaching a task to a cgroup
quite slow, and it can't be ignored in some situations.

A real case from Colin Cross: Android uses cgroups heavily to
manage thread priorities, putting threads in a background group
with reduced cpu.shares when they are not visible to the user,
and in a foreground group when they are. Some RPCs from foreground
threads to background threads will temporarily move the background
thread into the foreground group for the duration of the RPC.
This results in many calls to cgroup_attach_task.

In cgroup_attach_task() it's task->cgroups that is protected by RCU,
and put_css_set() calls kfree_rcu() to free it.

If we remove this synchronize_rcu(), there can be threads in RCU-read
sections accessing their old cgroup via current->cgroups with
concurrent rmdir operation, but this is safe.

 # time for ((i=0; i<50; i++)) { echo $$ > /mnt/sub/tasks; echo $$ > /mnt/tasks; }

real    0m2.524s
user    0m0.008s
sys     0m0.004s

With this patch:

real    0m0.004s
user    0m0.004s
sys     0m0.000s

tj: These synchronize_rcu()s are utterly confused.  synchornize_rcu()
    necessarily has to come between two operations to guarantee that
    the changes made by the former operation are visible to all rcu
    readers before proceeding to the latter operation.  Here,
    synchornize_rcu() are at the end of attach operations with nothing
    beyond it.  Its only effect would be delaying completion of
    write(2) to sysfs tasks/procs files until all rcu readers see the
    change, which doesn't mean anything.
Signed-off-by: NLi Zefan <lizefan@huawei.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NColin Cross <ccross@google.com>
      5d65bc0c
  9. 11 1月, 2013 1 次提交
  11. 08 1月, 2013 1 次提交
  13. 26 12月, 2012 1 次提交
    • E
      pidns: Stop pid allocation when init dies · c876ad76
      由 Eric W. Biederman 提交于 
      Oleg pointed out that in a pid namespace the sequence.
- pid 1 becomes a zombie
- setns(thepidns), fork,...
- reaping pid 1.
- The injected processes exiting.

Can lead to processes attempting access their child reaper and
instead following a stale pointer.

That waitpid for init can return before all of the processes in
the pid namespace have exited is also unfortunate.

Avoid these problems by disabling the allocation of new pids in a pid
namespace when init dies, instead of when the last process in a pid
namespace is reaped.
Pointed-out-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      c876ad76
  15. 25 12月, 2012 1 次提交
  17. 21 12月, 2012 2 次提交
  19. 20 12月, 2012 7 次提交
  21. 19 12月, 2012 3 次提交
  23. 18 12月, 2012 9 次提交
  25. 17 12月, 2012 1 次提交