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@linux.alibaba.com>
---
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
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -171,7 +171,7 @@ bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
vm_flags_t vm_flags);
long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
long freed);
-int isolate_hugetlb(struct folio *folio, struct list_head *list);
+bool isolate_hugetlb(struct folio *folio, struct list_head *list);
int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison);
int get_huge_page_for_hwpoison(unsigned long pfn, int flags,
bool *migratable_cleared);
@@ -413,9 +413,9 @@ static inline pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
return NULL;
}
-static inline int isolate_hugetlb(struct folio *folio, struct list_head *list)
+static inline bool isolate_hugetlb(struct folio *folio, struct list_head *list)
{
- return -EBUSY;
+ return false;
}
static inline int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3a01a9dbf445..75097e3abc18 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2932,6 +2932,10 @@ static int alloc_and_dissolve_hugetlb_folio(struct hstate *h,
spin_unlock_irq(&hugetlb_lock);
ret = isolate_hugetlb(old_folio, list);
spin_lock_irq(&hugetlb_lock);
+ if (!ret)
+ ret = -EBUSY;
+ else
+ ret = 0;
goto free_new;
} else if (!folio_test_hugetlb_freed(old_folio)) {
/*
@@ -3005,7 +3009,7 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
if (hstate_is_gigantic(h))
return -ENOMEM;
- if (folio_ref_count(folio) && !isolate_hugetlb(folio, list))
+ if (folio_ref_count(folio) && isolate_hugetlb(folio, list))
ret = 0;
else if (!folio_ref_count(folio))
ret = alloc_and_dissolve_hugetlb_folio(h, folio, list);
@@ -7251,15 +7255,15 @@ __weak unsigned long hugetlb_mask_last_page(struct hstate *h)
* These functions are overwritable if your architecture needs its own
* behavior.
*/
-int isolate_hugetlb(struct folio *folio, struct list_head *list)
+bool isolate_hugetlb(struct folio *folio, struct list_head *list)
{
- int ret = 0;
+ bool ret = true;
spin_lock_irq(&hugetlb_lock);
if (!folio_test_hugetlb(folio) ||
!folio_test_hugetlb_migratable(folio) ||
!folio_try_get(folio)) {
- ret = -EBUSY;
+ ret = false;
goto unlock;
}
folio_clear_hugetlb_migratable(folio);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e504362fdb23..8604753bc644 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2508,7 +2508,7 @@ static bool isolate_page(struct page *page, struct list_head *pagelist)
bool isolated = false;
if (PageHuge(page)) {
- isolated = !isolate_hugetlb(page_folio(page), pagelist);
+ isolated = isolate_hugetlb(page_folio(page), pagelist);
} else {
bool lru = !__PageMovable(page);
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 2751bc3310fd..a256a241fd1d 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -609,7 +609,7 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
if (flags & (MPOL_MF_MOVE_ALL) ||
(flags & MPOL_MF_MOVE && folio_estimated_sharers(folio) == 1 &&
!hugetlb_pmd_shared(pte))) {
- if (isolate_hugetlb(folio, qp->pagelist) &&
+ if (!isolate_hugetlb(folio, qp->pagelist) &&
(flags & MPOL_MF_STRICT))
/*
* Failed to isolate folio but allow migrating pages
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;
}
} else {
struct page *head;
--
2.27.0On Tue, 14 Feb 2023 21:59:31 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> 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@linux.alibaba.com>
> ---
> 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
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -171,7 +171,7 @@ bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
> vm_flags_t vm_flags);
> long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
> long freed);
> -int isolate_hugetlb(struct folio *folio, struct list_head *list);
> +bool isolate_hugetlb(struct folio *folio, struct list_head *list);
> int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison);
> int get_huge_page_for_hwpoison(unsigned long pfn, int flags,
> bool *migratable_cleared);
> @@ -413,9 +413,9 @@ static inline pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
> return NULL;
> }
>
> -static inline int isolate_hugetlb(struct folio *folio, struct list_head *list)
> +static inline bool isolate_hugetlb(struct folio *folio, struct list_head *list)
> {
> - return -EBUSY;
> + return false;
> }
>
> static inline int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison)
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 3a01a9dbf445..75097e3abc18 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -2932,6 +2932,10 @@ static int alloc_and_dissolve_hugetlb_folio(struct hstate *h,
> spin_unlock_irq(&hugetlb_lock);
> ret = isolate_hugetlb(old_folio, list);
> spin_lock_irq(&hugetlb_lock);
> + if (!ret)
> + ret = -EBUSY;
> + else
> + ret = 0;
This would work, but 'ret' is not 'bool' but 'int'. How about below?
ret = isolate_hugetlb(old_folio, list) ? 0 : -EBUSY;
> goto free_new;
> } else if (!folio_test_hugetlb_freed(old_folio)) {
> /*
> @@ -3005,7 +3009,7 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
> if (hstate_is_gigantic(h))
> return -ENOMEM;
>
> - if (folio_ref_count(folio) && !isolate_hugetlb(folio, list))
> + if (folio_ref_count(folio) && isolate_hugetlb(folio, list))
> ret = 0;
> else if (!folio_ref_count(folio))
> ret = alloc_and_dissolve_hugetlb_folio(h, folio, list);
> @@ -7251,15 +7255,15 @@ __weak unsigned long hugetlb_mask_last_page(struct hstate *h)
> * These functions are overwritable if your architecture needs its own
> * behavior.
> */
> -int isolate_hugetlb(struct folio *folio, struct list_head *list)
> +bool isolate_hugetlb(struct folio *folio, struct list_head *list)
> {
> - int ret = 0;
> + bool ret = true;
>
> spin_lock_irq(&hugetlb_lock);
> if (!folio_test_hugetlb(folio) ||
> !folio_test_hugetlb_migratable(folio) ||
> !folio_try_get(folio)) {
> - ret = -EBUSY;
> + ret = false;
> goto unlock;
> }
> folio_clear_hugetlb_migratable(folio);
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index e504362fdb23..8604753bc644 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2508,7 +2508,7 @@ static bool isolate_page(struct page *page, struct list_head *pagelist)
> bool isolated = false;
>
> if (PageHuge(page)) {
> - isolated = !isolate_hugetlb(page_folio(page), pagelist);
> + isolated = isolate_hugetlb(page_folio(page), pagelist);
> } else {
> bool lru = !__PageMovable(page);
>
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 2751bc3310fd..a256a241fd1d 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -609,7 +609,7 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
> if (flags & (MPOL_MF_MOVE_ALL) ||
> (flags & MPOL_MF_MOVE && folio_estimated_sharers(folio) == 1 &&
> !hugetlb_pmd_shared(pte))) {
> - if (isolate_hugetlb(folio, qp->pagelist) &&
> + if (!isolate_hugetlb(folio, qp->pagelist) &&
> (flags & MPOL_MF_STRICT))
> /*
> * Failed to isolate folio but allow migrating pages
> 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'.
Thanks,
SJ
> }
> } else {
> struct page *head;
> --
> 2.27.0
>
On Tue, 14 Feb 2023 18:03:24 +0000 SeongJae Park <sj@kernel.org> wrote:
> On Tue, 14 Feb 2023 21:59:31 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> 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@linux.alibaba.com>
> > ---
> > 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 ;)
Thanks,
SJ
>
>
> Thanks,
> SJ
>
> > }
> > } else {
> > struct page *head;
> > --
> > 2.27.0
> >
On 02/14/23 18:07, SeongJae Park wrote:
> On Tue, 14 Feb 2023 18:03:24 +0000 SeongJae Park <sj@kernel.org> wrote:
>
> > On Tue, 14 Feb 2023 21:59:31 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> 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@linux.alibaba.com>
> > > ---
> > > 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.
--
Mike Kravetz
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@kernel.org> wrote:
>>
>>> On Tue, 14 Feb 2023 21:59:31 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> 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@linux.alibaba.com>
>>>> ---
>>>> 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.
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