[PATCH v3 0/4] Change the return value for page isolation functions

From: Baolin Wang
Date: Wed Feb 15 2023 - 05:40:02 EST


Now the page isolation functions did not return a boolean to indicate
success or not, instead it will return a negative error when failed
to isolate a page. So below code used in most places seem a boolean
success/failure thing, which can confuse people whether the isolation
is successful.

if (folio_isolate_lru(folio))
continue;

Moreover the page isolation functions only return 0 or -EBUSY, and
most users did not care about the negative error except for few users,
thus we can convert all page isolation functions to return a boolean
value, which can remove the confusion to make code more clear.

No functional changes intended in this patch series.

Changes from v2:
- Add a new boolean 'isolated' variable for functions that require the
negative error value.
- Keep the same return value logic in do_migrate_range(), that means it
will return -EBUSY if all pages are failed to be isolated.
- Collect Acked-by and Reviewed-by tags. Thanks David and SeongJae.

Changes from v1:
- Convert all isolation functions to return bool.

Baolin Wang (4):
mm: change to return bool for folio_isolate_lru()
mm: change to return bool for isolate_lru_page()
mm: hugetlb: change to return bool for isolate_hugetlb()
mm: change to return bool for isolate_movable_page()

include/linux/hugetlb.h | 6 +++---
include/linux/migrate.h | 6 +++---
mm/compaction.c | 2 +-
mm/damon/paddr.c | 2 +-
mm/folio-compat.c | 4 ++--
mm/gup.c | 2 +-
mm/hugetlb.c | 13 ++++++++-----
mm/internal.h | 4 ++--
mm/khugepaged.c | 4 ++--
mm/madvise.c | 4 ++--
mm/memcontrol.c | 4 ++--
mm/memory-failure.c | 10 +++++-----
mm/memory_hotplug.c | 8 +++++---
mm/mempolicy.c | 4 ++--
mm/migrate.c | 20 +++++++++++---------
mm/migrate_device.c | 2 +-
mm/vmscan.c | 10 +++++-----
17 files changed, 56 insertions(+), 49 deletions(-)

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2.27.0