On Thu, Apr 25, 2024 at 11:40:48AM +0200, David Hildenbrand wrote:
> On 25.04.24 00:57, Luis Chamberlain wrote:
> > We should check as early as possible if we should bail due to writeback
> > or truncation. This will allow us to add further sanity checks earlier
> > as well.
> >
> > This introduces no functional changes.
> >
> > Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> > ---
> > mm/huge_memory.c | 23 +++++++++++------------
> > 1 file changed, 11 insertions(+), 12 deletions(-)
> >
> > While working on min order support for LBS this came up as an improvement
> > as we can check for the min order early earlier, so this sets the stage
> > up for that.
> >
> > diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> > index 86a8c7b3b8dc..32c701821e0d 100644
> > --- a/mm/huge_memory.c
> > +++ b/mm/huge_memory.c
> > @@ -3055,8 +3055,17 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
> > if (new_order >= folio_order(folio))
> > return -EINVAL;
> > - /* Cannot split anonymous THP to order-1 */
> > - if (new_order == 1 && folio_test_anon(folio)) {
> > + if (folio_test_writeback(folio))
> > + return -EBUSY;
> > +
>
> Why earlier than basic input parameter checks (new_order?
>
> Sorry, but I don't see the reason for that change. It's all happening
> extremely early, what are we concerned about?
>
> It's likely better to send that patch with the actual patch "to add further
> sanity checks earlier as well", and why they have to be that early.
It's a clear eye-sore when we add min order, I'll leave the eyesores for
others. It can wait.
Luis
