Re: [PATCH v2 3/4] mm: hugetlb: change to return bool for isolate_hugetlb()
From: Baolin Wang
Date: Tue Feb 14 2023 - 20:06:55 EST
On 2/15/2023 2:21 AM, Mike Kravetz wrote:
On 02/14/23 18:07, SeongJae Park wrote:
On Tue, 14 Feb 2023 18:03:24 +0000 SeongJae Park <sj@xxxxxxxxxx> wrote:
On Tue, 14 Feb 2023 21:59:31 +0800 Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> wrote:
Now the isolate_hugetlb() only returns 0 or -EBUSY, and most users did not
care about the negative value, thus we can convert the isolate_hugetlb()
to return a boolean value to make code more clear when checking the
hugetlb isolation state. Moreover converts 2 users which will consider
the negative value returned by isolate_hugetlb().
No functional changes intended.
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
---
include/linux/hugetlb.h | 6 +++---
mm/hugetlb.c | 12 ++++++++----
mm/memory-failure.c | 2 +-
mm/mempolicy.c | 2 +-
mm/migrate.c | 2 +-
5 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index df6dd624ccfe..5f5e4177b2e0 100644
[...]
diff --git a/mm/migrate.c b/mm/migrate.c
index 53010a142e7f..c5136fa48638 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2128,7 +2128,7 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
if (PageHead(page)) {
err = isolate_hugetlb(page_folio(page), pagelist);
if (!err)
- err = 1;
+ err = -EBUSY;
Again, I think this is confusing. 'err' is 'bool', not 'int'.
I mean, 'err' is not 'bool' but 'int', sorry. See? This confuses me ;)
Yes,
in the case here (and elsewhere) I like David's suggestion of using a separate
bool such as 'isolated' to capture the return value of the isolate function.
Then, the statement:
err = isolated ? 0 : -EBUSY;
would be pretty clear.
Yes, much better, will do. Thanks.