[RFC LPC2025 PATCH 1/4] mm/khugepaged: Remove hpage_collapse_scan_abort
From: Joshua Hahn <joshua.hahnjy@gmail.com>
Date: 2025-12-05 23:32:20
Also in:
linux-mm, lkml
Subsystem:
memory management, memory management - thp (transparent huge page), the rest, tracing · Maintainers:
Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Commit 14a4e2141e24 ("mm, thp: only collapse hugepages to nodes with
affinity for zone_reclaim_mode") introduced khugepaged_scan_abort,
which was later renamed to hpage_collapse_scan_abort. It prevents
collapsing hugepages to remote nodes when zone_reclaim_mode is enabled
as to prefer reclaiming & allocating locally instead of allocating on a
far away remote node (distance > RECLAIM_DISTANCE).
With the zone_reclaim_mode sysctl being deprecated later in the series,
remove hpage_collapse_scan_abort, its callers, and its associated values
in the scan_result enum.
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
---
include/trace/events/huge_memory.h | 1 -
mm/khugepaged.c | 34 ------------------------------
2 files changed, 35 deletions(-)
diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h
index 4cde53b45a85..1c0b146d1286 100644
--- a/include/trace/events/huge_memory.h
+++ b/include/trace/events/huge_memory.h@@ -20,7 +20,6 @@ EM( SCAN_PTE_MAPPED_HUGEPAGE, "pte_mapped_hugepage") \ EM( SCAN_LACK_REFERENCED_PAGE, "lack_referenced_page") \ EM( SCAN_PAGE_NULL, "page_null") \ - EM( SCAN_SCAN_ABORT, "scan_aborted") \ EM( SCAN_PAGE_COUNT, "not_suitable_page_count") \ EM( SCAN_PAGE_LRU, "page_not_in_lru") \ EM( SCAN_PAGE_LOCK, "page_locked") \
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 97d1b2824386..a93228a53ee4 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c@@ -40,7 +40,6 @@ enum scan_result { SCAN_PTE_MAPPED_HUGEPAGE, SCAN_LACK_REFERENCED_PAGE, SCAN_PAGE_NULL, - SCAN_SCAN_ABORT, SCAN_PAGE_COUNT, SCAN_PAGE_LRU, SCAN_PAGE_LOCK,
@@ -830,30 +829,6 @@ struct collapse_control khugepaged_collapse_control = { .is_khugepaged = true, }; -static bool hpage_collapse_scan_abort(int nid, struct collapse_control *cc) -{ - int i; - - /* - * If node_reclaim_mode is disabled, then no extra effort is made to - * allocate memory locally. - */ - if (!node_reclaim_enabled()) - return false; - - /* If there is a count for this node already, it must be acceptable */ - if (cc->node_load[nid]) - return false; - - for (i = 0; i < MAX_NUMNODES; i++) { - if (!cc->node_load[i]) - continue; - if (node_distance(nid, i) > node_reclaim_distance) - return true; - } - return false; -} - #define khugepaged_defrag() \ (transparent_hugepage_flags & \ (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
@@ -1355,10 +1330,6 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm, * hit record. */ node = folio_nid(folio); - if (hpage_collapse_scan_abort(node, cc)) { - result = SCAN_SCAN_ABORT; - goto out_unmap; - } cc->node_load[node]++; if (!folio_test_lru(folio)) { result = SCAN_PAGE_LRU;
@@ -2342,11 +2313,6 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, } node = folio_nid(folio); - if (hpage_collapse_scan_abort(node, cc)) { - result = SCAN_SCAN_ABORT; - folio_put(folio); - break; - } cc->node_load[node]++; if (!folio_test_lru(folio)) {
--
2.47.3