Re: [PATCH 4/5] blk-throttle: track buffered and anonymous pages

[Andrea Righi <arighi@develer.com>]

On Tue, Feb 22, 2011 at 03:49:28PM -0500, Vivek Goyal wrote:
> On Tue, Feb 22, 2011 at 10:42:41AM -0800, Chad Talbott wrote:
> > On Tue, Feb 22, 2011 at 9:12 AM, Andrea Righi <arighi@develer.com> wrote:
> > > Add the tracking of buffered (writeback) and anonymous pages.
> > ...
> > > ---
> > >  block/blk-throttle.c   |   87 +++++++++++++++++++++++++++++++++++++++++++++++-
> > >  include/linux/blkdev.h |   26 ++++++++++++++-
> > >  2 files changed, 111 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/block/blk-throttle.c b/block/blk-throttle.c
> > > index 9ad3d1e..a50ee04 100644
> > > --- a/block/blk-throttle.c
> > > +++ b/block/blk-throttle.c
> > ...
> > > +int blk_throtl_set_anonpage_owner(struct page *page, struct mm_struct *mm)
> > > +int blk_throtl_set_filepage_owner(struct page *page, struct mm_struct *mm)
> > > +int blk_throtl_copy_page_owner(struct page *npage, struct page *opage)
> > 
> > It would be nice if these were named blk_cgroup_*.  This is arguably
> > more correct as the id comes from the blkio subsystem, and isn't
> > specific to blk-throttle.  This will be more important very shortly,
> > as CFQ will be using this same cgroup id for async IO tracking soon.
> 
> Should this really be all part of blk-cgroup.c and not blk-throttle.c
> so that it can be used by CFQ code also down the line? Anyway all this
> is not throttle specific as such but blkio controller specific.

Agreed.

> 
> Though function naming convetion is not great in blk-cgroup.c But
> functions either have blkio_ prefix or blkiocg_ prefix.

ok.

> 
> Functions which are not directly dealing with cgroups or in general
> are called by blk-throttle.c and/or cfq-iosched.c I have marked as
> prefixed with "blkio_". Functions which directly deal with cgroup stuff
> and register with cgroup subsystem for this controller are generally
> having "blkiocg_" prefix.
> 
> In this case probably we can use probably blkio_ prefix.

ok.

Thanks,
-Andrea