Re: [PATCH v7 4/8] mm/huge_memory: add buddy allocator like (non-uniform) folio_split()

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 17 Feb 2025 10:22:44 -0500 Zi Yan <ziy@nvidia.com> wrote:

> >
> > Thanks. The patch below should fix it.
> >
> > I am going to send V8, since
> > 1. there have been 4 fixes so far for V7, a new series would help people
> > review;
> >
> > 2.  based on the discussion with you in THP cabal meeting, to
> > convert split_huge_page*() to use __folio_split(), the current
> > __folio_split() interface becomes awkward. Two changes are needed:
> >    a) use in folio offset instead of struct page, since even in
> >      truncate_inode_partial_folio() I needed to convert in folio offset
> >      struct page to use my current interface;
> >    b) split_huge_page*()'s caller might hold the page lock at a non-head
> >      page, so an additional keep_lock_at_in_folio_offset is needed
> >      to indicate which after-split folio should be kept locked after
> >      split is done.
> >
> 
> Hi Andrew,
> 
> I am planing to send V8 to collect all fixup patches I have so far plus
> the one below and change folio_split() interface and some of the code.
> What is your preferred method?
> 
> 1. you can pick up the fixup below and I send a new set of patches to
> change folio_split();
> 
> 2. I collect a new V8 with all fixup patches and folio_split() change.
> 
> For 1, the commit history might be messy due to my new folio_split()
> change. For 2, Minimize xa_node allocation during xarry split [1]
> patchset depends on patch 1 of this series, which adds some extra work
> for you to collect V8 (alternatively, I can send V8 without patch 1).

We're only at -rc3, so I'll remove both series from mm.git.  Please
fully resend both series against mm-unstable?