linux.git/lib/maple_tree.c, branch v7.1-rc2

MAINTAINERS: update Liam's email address

2026-04-27T12:54:25+00:00

Switching to private email address.  Update all contact information

Add an entry to mailmap at the same time.

Link: https://lore.kernel.org/20260422184310.2682901-1-liam@infradead.org
Signed-off-by: Liam R. Howlett 
Signed-off-by: Andrew Morton

maple_tree: clean up mas_wr_node_store()

2026-04-05T20:52:57+00:00

The new_end does not need to be passed in as the data is already being
checked.  This allows for other areas to skip getting the node new_end in
the calling function.

The type was incorrectly void * instead of void __rcu *, which isn't an
issue but is technically incorrect.

Move the variable assignment to after the declarations to clean up the
initial setup.

Ensure there is something to copy before calling memcpy().

Link: https://lkml.kernel.org/r/20260130205935.2559335-31-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: Alice Ryhl 
Cc: Andrew Ballance 
Cc: Arnd Bergmann 
Cc: Christian Kujau 
Cc: Geert Uytterhoeven 
Cc: Kuninori Morimoto 
Cc: Matthew Wilcox (Oracle) 
Cc: SeongJae Park 
Cc: Sidhartha Kumar 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

maple_tree: don't pass end to mas_wr_append()

2026-04-05T20:52:57+00:00

Figure out the end internally.  This is necessary for future cleanups.

Link: https://lkml.kernel.org/r/20260130205935.2559335-30-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: Alice Ryhl 
Cc: Andrew Ballance 
Cc: Arnd Bergmann 
Cc: Christian Kujau 
Cc: Geert Uytterhoeven 
Cc: Kuninori Morimoto 
Cc: Matthew Wilcox (Oracle) 
Cc: SeongJae Park 
Cc: Sidhartha Kumar 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

maple_tree: pass maple copy node to mas_wmb_replace()

2026-04-05T20:52:57+00:00

mas_wmb_replace() is called in three places with the same setup, move the
setup into the function itself.  The function needs to be relocated as it
calls mtree_range_walk().

Link: https://lkml.kernel.org/r/20260130205935.2559335-29-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: Alice Ryhl 
Cc: Andrew Ballance 
Cc: Arnd Bergmann 
Cc: Christian Kujau 
Cc: Geert Uytterhoeven 
Cc: Kuninori Morimoto 
Cc: Matthew Wilcox (Oracle) 
Cc: SeongJae Park 
Cc: Sidhartha Kumar 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

maple_tree: remove maple big node and subtree structs

2026-04-05T20:52:57+00:00

Now that no one uses the structures and functions, drop the dead code.

Link: https://lkml.kernel.org/r/20260130205935.2559335-28-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: Alice Ryhl 
Cc: Andrew Ballance 
Cc: Arnd Bergmann 
Cc: Christian Kujau 
Cc: Geert Uytterhoeven 
Cc: Kuninori Morimoto 
Cc: Matthew Wilcox (Oracle) 
Cc: SeongJae Park 
Cc: Sidhartha Kumar 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

maple_tree: use maple copy node for mas_wr_split()

2026-04-05T20:52:56+00:00

Instead of using the maple big node, use the maple copy node for reduced
stack usage and aligning with mas_wr_rebalance() and
mas_wr_spanning_store().

Splitting a node is similar to rebalancing, but a new evaluation of when
to ascend is needed.  The only other difference is that the data is pushed
and never rebalanced at each level.

The testing must also align with the changes to this commit to ensure the
test suite continues to pass.

Link: https://lkml.kernel.org/r/20260130205935.2559335-27-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: Alice Ryhl 
Cc: Andrew Ballance 
Cc: Arnd Bergmann 
Cc: Christian Kujau 
Cc: Geert Uytterhoeven 
Cc: Kuninori Morimoto 
Cc: Matthew Wilcox (Oracle) 
Cc: SeongJae Park 
Cc: Sidhartha Kumar 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

maple_tree: add cp_converged() helper

2026-04-05T20:52:56+00:00

When the maple copy node converges into a single entry, then certain
operations can stop ascending the tree.

This is used more later.

Link: https://lkml.kernel.org/r/20260130205935.2559335-26-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: Alice Ryhl 
Cc: Andrew Ballance 
Cc: Arnd Bergmann 
Cc: Christian Kujau 
Cc: Geert Uytterhoeven 
Cc: Kuninori Morimoto 
Cc: Matthew Wilcox (Oracle) 
Cc: SeongJae Park 
Cc: Sidhartha Kumar 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

maple_tree: add copy_tree_location() helper

2026-04-05T20:52:56+00:00

Extract the copying of the tree location from one maple state to another
into its own function.  This is used more later.

Link: https://lkml.kernel.org/r/20260130205935.2559335-25-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: Alice Ryhl 
Cc: Andrew Ballance 
Cc: Arnd Bergmann 
Cc: Christian Kujau 
Cc: Geert Uytterhoeven 
Cc: Kuninori Morimoto 
Cc: Matthew Wilcox (Oracle) 
Cc: SeongJae Park 
Cc: Sidhartha Kumar 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

maple_tree: use maple copy node for mas_wr_rebalance() operation

2026-04-05T20:52:56+00:00

Stop using the maple big node for rebalance operations by changing to more
align with spanning store.  The rebalance operation needs its own data
calculation in rebalance_data().

In the event of too much data, the rebalance tries to push the data using
push_data_sib().  If there is insufficient data, the rebalance operation
will rebalance against a sibling (found with rebalance_sib()).

The rebalance starts at the leaf and works its way upward in the tree
using rebalance_ascend().  Most of the code is shared with spanning store
such as the copy node having a new root, but is fundamentally different in
that the data must come from a sibling.

A parent maple state is used to track the parent location to avoid
multiple mas_ascend() calls.  The maple state tree location is copied from
the parent to the mas (child) in the ascend step.  Ascending itself is
done in the main loop.

Link: https://lkml.kernel.org/r/20260130205935.2559335-23-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: Alice Ryhl 
Cc: Andrew Ballance 
Cc: Arnd Bergmann 
Cc: Christian Kujau 
Cc: Geert Uytterhoeven 
Cc: Kuninori Morimoto 
Cc: Matthew Wilcox (Oracle) 
Cc: SeongJae Park 
Cc: Sidhartha Kumar 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

maple_tree: add cp_is_new_root() helper

2026-04-05T20:52:56+00:00

Add a helper to do what is needed when the maple copy node contains a new
root node.  This is useful for future commits and is self-documenting
code.

[Liam.Howlett@oracle.com: remove warnings on older compilers]
  Link: https://lkml.kernel.org/r/malwmirqnpuxqkqrobcmzfkmmxipoyzwfs2nwc5fbpxlt2r2ej@wchmjtaljvw3
[akpm@linux-foundation.org: s/cp->slot[0]/&cp->slot[0]/, per Liam]
Link: https://lkml.kernel.org/r/20260130205935.2559335-22-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: Alice Ryhl 
Cc: Andrew Ballance 
Cc: Arnd Bergmann 
Cc: Christian Kujau 
Cc: Geert Uytterhoeven 
Cc: Kuninori Morimoto 
Cc: Matthew Wilcox (Oracle) 
Cc: SeongJae Park 
Cc: Sidhartha Kumar 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton