mbox series

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

Message ID cover.1676424378.git.baolin.wang@linux.alibaba.com
Headers
Series Change the return value for page isolation functions |

Message

Baolin Wang Feb. 15, 2023, 10:39 a.m. UTC 
  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(-)

Comments

Linus Torvalds Feb. 15, 2023, 8:14 p.m. UTC | #1 
This v3 series looks like it's making things more readable, so ack as
far as I'm concerned.

But it looks like it's firmly in the "Andrew's mm tree" category, so
I'll leave it up to him to decide.

                   Linus
SeongJae Park Feb. 15, 2023, 8:26 p.m. UTC | #2 
Hi Baolin,

On Wed, 15 Feb 2023 18:39:33 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> wrote:

> 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.

For the series,

Reviewed-by: SeongJae Park <sj@kernel.org>


Thanks,
SJ

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