On 5/31/24 6:05 AM, David Hildenbrand wrote:
On 31.05.24 15:04, David Hildenbrand wrote:
On 30.05.24 19:14, Sidhartha Kumar wrote:
By using a folio in scan_movable_pages() we convert the last user of the
page-based hugetlb information macro functions to the folio version.
After this conversion, we can safely remove the page-based definitions
from include/linux/hugetlb.h.
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
---
v1 -> v2:
simplify pfn skipping logic with pfn |= folio_nr_pages(folio) - 1
per Matthew
include/linux/hugetlb.h | 6 +-----
mm/memory_hotplug.c | 11 +++++------
2 files changed, 6 insertions(+), 11 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 15a58f69782c..279aca379b95 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -616,9 +616,7 @@ static __always_inline \
bool folio_test_hugetlb_##flname(struct folio *folio) \
{ void *private = &folio->private; \
return test_bit(HPG_##flname, private); \
- } \
-static inline int HPage##uname(struct page *page) \
- { return test_bit(HPG_##flname, &(page->private)); }
+ }
#define SETHPAGEFLAG(uname, flname) \
static __always_inline \
@@ -637,8 +635,6 @@ void folio_clear_hugetlb_##flname(struct folio
*folio) \
#define TESTHPAGEFLAG(uname, flname) \
static inline bool \
folio_test_hugetlb_##flname(struct folio *folio) \
- { return 0; } \
-static inline int HPage##uname(struct page *page) \
{ return 0; }
#define SETHPAGEFLAG(uname, flname) \
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 431b1f6753c0..9c36eb3bbd3b 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1731,8 +1731,8 @@ static int scan_movable_pages(unsigned long start,
unsigned long end,
unsigned long pfn;
for (pfn = start; pfn < end; pfn++) {
- struct page *page, *head;
- unsigned long skip;
+ struct page *page;
+ struct folio *folio;
if (!pfn_valid(pfn))
continue;
@@ -1753,7 +1753,7 @@ static int scan_movable_pages(unsigned long start,
unsigned long end,
if (!PageHuge(page))
continue;
- head = compound_head(page);
+ folio = page_folio(page);
/*
* This test is racy as we hold no reference or lock. The
* hugetlb page could have been free'ed and head is no longer
@@ -1761,10 +1761,9 @@ static int scan_movable_pages(unsigned long start,
unsigned long end,
* cases false positives and negatives are possible. Calling
* code must deal with these scenarios.
*/
- if (HPageMigratable(head))
+ if (folio_test_hugetlb_migratable(folio))
goto found;
- skip = compound_nr(head) - (pfn - page_to_pfn(head));
- pfn += skip - 1;
+ pfn |= folio_nr_pages(folio) - 1;
Likely not exactly what we want?
pfn |= folio_nr_pages(folio);
Would make sure that we are "one PFN before the start of the next
folio". The pfn++ before the next loop iteration would move us to the
next folio.
Or am I missing something?
Okay, I got it wrong.
"folio_nr_pages(folio) - 1" gives us the bitmask to land one PFN before the end.
ya because folio_nr_pages() will be a power of 2, subtracting 1 turns it into a
bitmask.
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Thanks for taking a look at this.
It might be cleaner if we would handle the "pfn++;" on the "continue;"
paths inmstead, and simply here do something like
pfn = ALIGN(pfn + 1, folio_nr_pages(folio));
instead.
