hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8YUPE CVE: NA

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With dynamic hugetlb feature, some memory is isolated in the dynamic pool. When try to compact memory, the kcompactd thread will scan all memory, althougt some memory is belonging to dynamic pool, kcompactd still try to migrate them. After migration, these memory will free to dynamic pool rather than buddy system, which results the free pages in buddy system decreased.

Since it is unnecessary to compact the memory in the dynamic pool, skip migrate them to fix the problem.

The same problem also existed in alloc_contig_range(), offline_pages() and numa balancing. Skip it again in these three scenarios.

In addition to this, we have to consider the migration of hugepage, if a hugepage is from dynamic pool, we should not allow to migrate it.

Signed-off-by: Liu Shixin liushixin2@huawei.com --- include/linux/dynamic_hugetlb.h | 4 ++-- mm/compaction.c | 4 ++++ mm/migrate.c | 7 +++++++ mm/page_isolation.c | 4 +++- 4 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/include/linux/dynamic_hugetlb.h b/include/linux/dynamic_hugetlb.h index eff31669e210..06b20a24dfe6 100644 --- a/include/linux/dynamic_hugetlb.h +++ b/include/linux/dynamic_hugetlb.h @@ -184,12 +184,12 @@ static inline void free_huge_page_to_dhugetlb_pool(struct page *page, bool restore_reserve) { } +#endif + static inline bool page_belong_to_dynamic_hugetlb(struct page *page) { return false; } -#endif - #endif /* CONFIG_DYNAMIC_HUGETLB */ #endif /* __LINUX_DYNAMIC_HUGETLB_H */ diff --git a/mm/compaction.c b/mm/compaction.c index bdcde6ea7f97..754734a649d5 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -23,6 +23,7 @@ #include <linux/freezer.h> #include <linux/page_owner.h> #include <linux/psi.h> +#include <linux/dynamic_hugetlb.h> #include "internal.h"

#ifdef CONFIG_COMPACTION @@ -1862,6 +1863,9 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc) if (!page) continue;

+ if (page_belong_to_dynamic_hugetlb(page)) + continue; + /* * If isolation recently failed, do not retry. Only check the * pageblock once. COMPACT_CLUSTER_MAX causes a pageblock diff --git a/mm/migrate.c b/mm/migrate.c index 9d40b1264a8b..c8491a744e8c 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -49,6 +49,7 @@ #include <linux/sched/mm.h> #include <linux/ptrace.h> #include <linux/oom.h> +#include <linux/dynamic_hugetlb.h>

#include <asm/tlbflush.h>

@@ -1611,6 +1612,9 @@ struct page *alloc_migration_target(struct page *page, unsigned long private) if (PageHuge(page)) { struct hstate *h = page_hstate(compound_head(page));

+ if (page_belong_to_dynamic_hugetlb(page)) + return NULL; + gfp_mask = htlb_modify_alloc_mask(h, gfp_mask); return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask); } @@ -2088,6 +2092,9 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) if (!migrate_balanced_pgdat(pgdat, compound_nr(page))) return 0;

+ if (page_belong_to_dynamic_hugetlb(page)) + return 0; + if (isolate_lru_page(page)) return 0;

diff --git a/mm/page_isolation.c b/mm/page_isolation.c index bddf788f45bf..48a0ee9cef0a 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -10,6 +10,7 @@ #include <linux/hugetlb.h> #include <linux/page_owner.h> #include <linux/migrate.h> +#include <linux/dynamic_hugetlb.h> #include "internal.h"

#define CREATE_TRACE_POINTS @@ -195,7 +196,8 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); if (page) { - if (set_migratetype_isolate(page, migratetype, flags)) { + if (page_belong_to_dynamic_hugetlb(page) || + set_migratetype_isolate(page, migratetype, flags)) { undo_pfn = pfn; goto undo; }