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ksm: initialize the addr only once in rmap_walk_ksm

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This is a minor performance optimization, especially when there are many
for-loop iterations, because the addr variable doesn't change across
iterations.

Therefore, it only needs to be initialized once before the loop.

Link: https://lkml.kernel.org/r/20260212192820223O_r2NQzSEPG_C56cs-z4l@zte.com.cn
Link: https://lkml.kernel.org/r/20260212192932941MSsJEAyoRW4YdLBN7_myn@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Hugh Dickins <hughd@google.com>
Cc: Wang Yaxin <wang.yaxin@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
xu xin 2026-02-12 19:29:32 +08:00 committed by Andrew Morton
parent 34ca46cc6f
commit 318d87b8fa
1 changed files with 3 additions and 4 deletions
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7
mm/ksm.c
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@ -3168,6 +3168,8 @@ void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc)
return; return;
again: again:
hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) { hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {
/* Ignore the stable/unstable/sqnr flags */
const unsigned long addr = rmap_item->address & PAGE_MASK;
struct anon_vma *anon_vma = rmap_item->anon_vma; struct anon_vma *anon_vma = rmap_item->anon_vma;
struct anon_vma_chain *vmac; struct anon_vma_chain *vmac;
struct vm_area_struct *vma; struct vm_area_struct *vma;
@ -3180,16 +3182,13 @@ void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc)
} }
anon_vma_lock_read(anon_vma); anon_vma_lock_read(anon_vma);
} }
anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root, anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root,
0, ULONG_MAX) { 0, ULONG_MAX) {
unsigned long addr;
cond_resched(); cond_resched();
vma = vmac->vma; vma = vmac->vma;
/* Ignore the stable/unstable/sqnr flags */
addr = rmap_item->address & PAGE_MASK;
if (addr < vma->vm_start || addr >= vma->vm_end) if (addr < vma->vm_start || addr >= vma->vm_end)
continue; continue;
/* /*