| Message ID | c6038c7e823d4162f745147628616f7876585a97.1724054125.git.baolin.wang@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | support shmem mTHP collapse | expand |
On 19.08.24 10:14, Baolin Wang wrote: > Use the number of pages in the folio to check the reference count as > preparation for supporting shmem mTHP collapse. > > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> > --- > mm/khugepaged.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index f11b4f172e61..60d95f08610c 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1994,7 +1994,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, > /* > * We control three references to the folio: ^ "three" is wrong now. > * - we hold a pin on it; > - * - one reference from page cache; > + * - nr_pages reference from page cache; > * - one from lru_isolate_folio; > * If those are the only references, then any new usage > * of the folio will have to fetch it from the page > @@ -2002,7 +2002,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, > * truncate, so any new usage will be blocked until we > * unlock folio after collapse/during rollback. > */ > - if (folio_ref_count(folio) != 3) { > + if (folio_ref_count(folio) != 2 + folio_nr_pages(folio)) { > result = SCAN_PAGE_COUNT; > xas_unlock_irq(&xas); > folio_putback_lru(folio); > @@ -2185,7 +2185,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, > folio_clear_active(folio); > folio_clear_unevictable(folio); > folio_unlock(folio); > - folio_put_refs(folio, 3); > + folio_put_refs(folio, 2 + folio_nr_pages(folio)); > } > > goto out; Acked-by: David Hildenbrand <david@redhat.com>
On 2024/8/19 17:40, David Hildenbrand wrote: > On 19.08.24 10:14, Baolin Wang wrote: >> Use the number of pages in the folio to check the reference count as >> preparation for supporting shmem mTHP collapse. >> >> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> >> --- >> mm/khugepaged.c | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/mm/khugepaged.c b/mm/khugepaged.c >> index f11b4f172e61..60d95f08610c 100644 >> --- a/mm/khugepaged.c >> +++ b/mm/khugepaged.c >> @@ -1994,7 +1994,7 @@ static int collapse_file(struct mm_struct *mm, >> unsigned long addr, >> /* >> * We control three references to the folio: > > ^ "three" is wrong now. Ah, good catch. Will change to '2 + nr_pages'. > >> * - we hold a pin on it; >> - * - one reference from page cache; >> + * - nr_pages reference from page cache; >> * - one from lru_isolate_folio; >> * If those are the only references, then any new usage >> * of the folio will have to fetch it from the page >> @@ -2002,7 +2002,7 @@ static int collapse_file(struct mm_struct *mm, >> unsigned long addr, >> * truncate, so any new usage will be blocked until we >> * unlock folio after collapse/during rollback. >> */ >> - if (folio_ref_count(folio) != 3) { >> + if (folio_ref_count(folio) != 2 + folio_nr_pages(folio)) { >> result = SCAN_PAGE_COUNT; >> xas_unlock_irq(&xas); >> folio_putback_lru(folio); >> @@ -2185,7 +2185,7 @@ static int collapse_file(struct mm_struct *mm, >> unsigned long addr, >> folio_clear_active(folio); >> folio_clear_unevictable(folio); >> folio_unlock(folio); >> - folio_put_refs(folio, 3); >> + folio_put_refs(folio, 2 + folio_nr_pages(folio)); >> } >> goto out; > > Acked-by: David Hildenbrand <david@redhat.com> Thanks for reviewing.
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index f11b4f172e61..60d95f08610c 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1994,7 +1994,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, /* * We control three references to the folio: * - we hold a pin on it; - * - one reference from page cache; + * - nr_pages reference from page cache; * - one from lru_isolate_folio; * If those are the only references, then any new usage * of the folio will have to fetch it from the page @@ -2002,7 +2002,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, * truncate, so any new usage will be blocked until we * unlock folio after collapse/during rollback. */ - if (folio_ref_count(folio) != 3) { + if (folio_ref_count(folio) != 2 + folio_nr_pages(folio)) { result = SCAN_PAGE_COUNT; xas_unlock_irq(&xas); folio_putback_lru(folio); @@ -2185,7 +2185,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, folio_clear_active(folio); folio_clear_unevictable(folio); folio_unlock(folio); - folio_put_refs(folio, 3); + folio_put_refs(folio, 2 + folio_nr_pages(folio)); } goto out;
Use the number of pages in the folio to check the reference count as preparation for supporting shmem mTHP collapse. Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> --- mm/khugepaged.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)