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

Chad Talbott
2011-02-22T18:42:47Z

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.

is_kernel_io() is a good idea, it avoids a bug that we've run into
with CFQ async IO tracking. Why isn't PF_KTHREAD sufficient to cover
all kernel threads, including kswapd and those marked PF_MEMALLOC?

Thanks,
Chad