Re: [patch 3/4] io controller: Core IO controller implementation logic

On Thu, 06 Nov 2008 10:30:25 -0500
vgoyal@redhat.com wrote:

o Core IO controller implementation

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>

2 comments after a quick look.

 - I don't recommend generic work queue. More stacked dependency between "work"
   is not good. (I think disk-driver uses "work" for their jobs.)

 - It seems this bio-cgroup can queue the bio to infinite. Then, a process can submit
   io unitl cause OOM.
   (IIUC, Dirty bit of the page is cleared at submitting I/O. 
    Then dirty_ratio can't help us.)
   please add "wait for congestion by sleeping" code in bio-cgroup.


Thanks,
-Kame