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mm/ksm: use folio in remove_stable_node

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Pages in stable tree are all single normal page, so uses ksm_get_folio()
and folio_set_stable_node(), also saves 3 calls to compound_head().

Link: https://lkml.kernel.org/r/20240411061713.1847574-5-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Alex Shi (tencent) 2024-04-11 14:17:05 +08:00 committed by Andrew Morton
parent b8b0ff244d
commit 9d5cc14093
1 changed files with 12 additions and 12 deletions
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24
mm/ksm.c
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@ -1121,13 +1121,13 @@ static inline void folio_set_stable_node(struct folio *folio,
*/
static int remove_stable_node(struct ksm_stable_node *stable_node)
{
struct page *page;
struct folio *folio;
int err;
page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK);
if (!page) {
folio = ksm_get_folio(stable_node, GET_KSM_PAGE_LOCK);
if (!folio) {
/*
* get_ksm_page did remove_node_from_stable_tree itself.
* ksm_get_folio did remove_node_from_stable_tree itself.
*/
return 0;
}
@ -1138,22 +1138,22 @@ static int remove_stable_node(struct ksm_stable_node *stable_node)
* merge_across_nodes/max_page_sharing be switched.
*/
err = -EBUSY;
if (!page_mapped(page)) {
if (!folio_mapped(folio)) {
/*
* The stable node did not yet appear stale to get_ksm_page(),
* since that allows for an unmapped ksm page to be recognized
* The stable node did not yet appear stale to ksm_get_folio(),
* since that allows for an unmapped ksm folio to be recognized
* right up until it is freed; but the node is safe to remove.
* This page might be in an LRU cache waiting to be freed,
* or it might be PageSwapCache (perhaps under writeback),
* This folio might be in an LRU cache waiting to be freed,
* or it might be in the swapcache (perhaps under writeback),
* or it might have been removed from swapcache a moment ago.
*/
set_page_stable_node(page, NULL);
folio_set_stable_node(folio, NULL);
remove_node_from_stable_tree(stable_node);
err = 0;
}
unlock_page(page);
put_page(page);
folio_unlock(folio);
folio_put(folio);
return err;
}