The patch titled
Subject: maple_tree: reduce resets during store setup
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-reduce-resets-during-store-setup.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-reduce-resets-during-store-setup.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Subject: maple_tree: reduce resets during store setup
Date: Mon, 24 Jul 2023 14:31:56 -0400
mas_prealloc() may walk partially down the tree before finding that a
split or spanning store is needed. When the write occurs, relax the
logic on resetting the walk so that partial walks will not restart, but
walks that have gone too far (a store that affects beyond the current
node) should be restarted.
Link: https://lkml.kernel.org/r/20230724183157.3939892-15-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 37 ++++++++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 11 deletions(-)
--- a/lib/maple_tree.c~maple_tree-reduce-resets-during-store-setup
+++ a/lib/maple_tree.c
@@ -5424,19 +5424,34 @@ static inline void mte_destroy_walk(stru
static void mas_wr_store_setup(struct ma_wr_state *wr_mas)
{
+ if (mas_is_start(wr_mas->mas))
+ return;
+
if (unlikely(mas_is_paused(wr_mas->mas)))
- mas_reset(wr_mas->mas);
+ goto reset;
+
+ if (unlikely(mas_is_none(wr_mas->mas)))
+ goto reset;
+
+ /*
+ * A less strict version of mas_is_span_wr() where we allow spanning
+ * writes within this node. This is to stop partial walks in
+ * mas_prealloc() from being reset.
+ */
+ if (wr_mas->mas->last > wr_mas->mas->max)
+ goto reset;
+
+ if (wr_mas->entry)
+ return;
+
+ if (mte_is_leaf(wr_mas->mas->node) &&
+ wr_mas->mas->last == wr_mas->mas->max)
+ goto reset;
+
+ return;
- if (!mas_is_start(wr_mas->mas)) {
- if (mas_is_none(wr_mas->mas)) {
- mas_reset(wr_mas->mas);
- } else {
- wr_mas->r_max = wr_mas->mas->max;
- wr_mas->type = mte_node_type(wr_mas->mas->node);
- if (mas_is_span_wr(wr_mas))
- mas_reset(wr_mas->mas);
- }
- }
+reset:
+ mas_reset(wr_mas->mas);
}
/* Interface */
_
Patches currently in -mm which might be from Liam.Howlett@xxxxxxxxxx are
mm-mmap-clean-up-validate_mm-calls.patch
maple_tree-relax-lockdep-checks-for-on-stack-trees.patch
mm-mmap-change-detached-vma-locking-scheme.patch
maple_tree-be-more-strict-about-locking.patch
maple_tree-add-benchmarking-for-mas_for_each.patch
maple_tree-add-benchmarking-for-mas_prev.patch
mm-change-do_vmi_align_munmap-tracking-of-vmas-to-remove.patch
mm-remove-prev-check-from-do_vmi_align_munmap.patch
maple_tree-introduce-__mas_set_range.patch
mm-remove-re-walk-from-mmap_region.patch
maple_tree-re-introduce-entry-to-mas_preallocate-arguments.patch
maple_tree-adjust-node-allocation-on-mas_rebalance.patch
mm-use-vma_iter_clear_gfp-in-nommu.patch
mm-set-up-vma-iterator-for-vma_iter_prealloc-calls.patch
maple_tree-move-mas_wr_end_piv-below-mas_wr_extend_null.patch
maple_tree-update-mas_preallocate-testing.patch
maple_tree-refine-mas_preallocate-node-calculations.patch
maple_tree-reduce-resets-during-store-setup.patch
mm-mmap-change-vma-iteration-order-in-do_vmi_align_munmap.patch
