[PATCH 10/10] mm/madvise: share cold and pageout walk setup

[Gregory Price]

The MADV_COLD and MADV_PAGEOUT entry points duplicate the TLB and page-walk
setup while initializing equivalent private state.

Use one madvise_lru_vma_range() helper for the shared TLB lifecycle. Keep
operation-specific validation and policy in the two entry points.

No functional change intended.

Assisted-by: LLM
Signed-off-by: Gregory Price (Meta) <gou...@gourry.net>
---
 mm/madvise.c | 49 +++++++++++++++++--------------------------------
 1 file changed, 17 insertions(+), 32 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index 88a4a03dee04c..37e3d3a205a76 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -622,21 +622,19 @@ static const struct mm_walk_ops cold_walk_ops = {
        .walk_lock = PGWALK_RDLOCK,
 };
 
-static void madvise_cold_page_range(struct mmu_gather *tlb,
-               struct madvise_behavior *madv_behavior)
-
+static void
+madvise_lru_vma_range(struct madvise_behavior *madv_behavior,
+               struct madvise_walk_private *walk_private)
 {
        struct vm_area_struct *vma = madv_behavior->vma;
        struct madvise_behavior_range *range = &madv_behavior->range;
-       struct madvise_walk_private walk_private = {
-               .pageout = false,
-               .tlb = tlb,
-       };
 
-       tlb_start_vma(tlb, vma);
+       tlb_gather_mmu(walk_private->tlb, madv_behavior->mm);
+       tlb_start_vma(walk_private->tlb, vma);
        walk_page_range_vma(vma, range->start, range->end, &cold_walk_ops,
-                       &walk_private);
-       tlb_end_vma(tlb, vma);
+                           walk_private);
+       tlb_end_vma(walk_private->tlb, vma);
+       tlb_finish_mmu(walk_private->tlb);
 }
 
 static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
@@ -647,39 +645,28 @@ static inline bool can_madv_lru_vma(struct vm_area_struct 
*vma)
 static long madvise_cold(struct madvise_behavior *madv_behavior)
 {
        struct vm_area_struct *vma = madv_behavior->vma;
-       struct mmu_gather tlb;
+       struct madvise_walk_private walk_private = {
+               .tlb = madv_behavior->tlb,
+               .pageout = false,
+       };
 
        if (!can_madv_lru_vma(vma))
                return -EINVAL;
 
        lru_add_drain();
-       tlb_gather_mmu(&tlb, madv_behavior->mm);
-       madvise_cold_page_range(&tlb, madv_behavior);
-       tlb_finish_mmu(&tlb);
+       madvise_lru_vma_range(madv_behavior, &walk_private);
 
        return 0;
 }
 
-static void madvise_pageout_page_range(struct mmu_gather *tlb,
-               struct vm_area_struct *vma,
-               struct madvise_behavior_range *range)
+static long madvise_pageout(struct madvise_behavior *madv_behavior)
 {
+       struct vm_area_struct *vma = madv_behavior->vma;
        struct madvise_walk_private walk_private = {
+               .tlb = madv_behavior->tlb,
                .pageout = true,
-               .tlb = tlb,
        };
 
-       tlb_start_vma(tlb, vma);
-       walk_page_range_vma(vma, range->start, range->end, &cold_walk_ops,
-                           &walk_private);
-       tlb_end_vma(tlb, vma);
-}
-
-static long madvise_pageout(struct madvise_behavior *madv_behavior)
-{
-       struct mmu_gather tlb;
-       struct vm_area_struct *vma = madv_behavior->vma;
-
        if (!can_madv_lru_vma(vma))
                return -EINVAL;
 
@@ -694,9 +681,7 @@ static long madvise_pageout(struct madvise_behavior 
*madv_behavior)
                return 0;
 
        lru_add_drain();
-       tlb_gather_mmu(&tlb, madv_behavior->mm);
-       madvise_pageout_page_range(&tlb, vma, &madv_behavior->range);
-       tlb_finish_mmu(&tlb);
+       madvise_lru_vma_range(madv_behavior, &walk_private);
 
        return 0;
 }
-- 
2.53.0-Meta