| Message ID | 20210617184507.3662-3-joao.m.martins@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm, sparse-vmemmap: Introduce compound pagemaps | expand |
On 6/17/21 11:44 AM, Joao Martins wrote: > Split the utility function prep_compound_page() into head and tail > counterparts, and use them accordingly. > > This is in preparation for sharing the storage for / deduplicating > compound page metadata. > > Signed-off-by: Joao Martins <joao.m.martins@oracle.com> > --- > mm/page_alloc.c | 32 +++++++++++++++++++++----------- > 1 file changed, 21 insertions(+), 11 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 8836e54721ae..95967ce55829 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -741,24 +741,34 @@ void free_compound_page(struct page *page) > free_the_page(page, compound_order(page)); > } > > +static void prep_compound_head(struct page *page, unsigned int order) > +{ > + set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); > + set_compound_order(page, order); > + atomic_set(compound_mapcount_ptr(page), -1); > + if (hpage_pincount_available(page)) > + atomic_set(compound_pincount_ptr(page), 0); > +} > + > +static void prep_compound_tail(struct page *head, int tail_idx) > +{ > + struct page *p = head + tail_idx; > + > + set_page_count(p, 0); When you rebase, you should notice this has been removed from prep_compound_page as all tail pages should have zero ref count. > + p->mapping = TAIL_MAPPING; > + set_compound_head(p, head); > +} > + > void prep_compound_page(struct page *page, unsigned int order) > { > int i; > int nr_pages = 1 << order; > > __SetPageHead(page); > - for (i = 1; i < nr_pages; i++) { > - struct page *p = page + i; > - set_page_count(p, 0); > - p->mapping = TAIL_MAPPING; > - set_compound_head(p, page); > - } > + for (i = 1; i < nr_pages; i++) > + prep_compound_tail(page, i); > > - set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); > - set_compound_order(page, order); > - atomic_set(compound_mapcount_ptr(page), -1); > - if (hpage_pincount_available(page)) > - atomic_set(compound_pincount_ptr(page), 0); > + prep_compound_head(page, order); > } > > #ifdef CONFIG_DEBUG_PAGEALLOC > I'll need something like this for demote hugetlb page fuinctionality when the pages being demoted have been optimized for minimal vmemmap usage. Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
On 7/13/21 1:02 AM, Mike Kravetz wrote: > On 6/17/21 11:44 AM, Joao Martins wrote: >> Split the utility function prep_compound_page() into head and tail >> counterparts, and use them accordingly. >> >> This is in preparation for sharing the storage for / deduplicating >> compound page metadata. >> >> Signed-off-by: Joao Martins <joao.m.martins@oracle.com> >> --- >> mm/page_alloc.c | 32 +++++++++++++++++++++----------- >> 1 file changed, 21 insertions(+), 11 deletions(-) >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 8836e54721ae..95967ce55829 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -741,24 +741,34 @@ void free_compound_page(struct page *page) >> free_the_page(page, compound_order(page)); >> } >> >> +static void prep_compound_head(struct page *page, unsigned int order) >> +{ >> + set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); >> + set_compound_order(page, order); >> + atomic_set(compound_mapcount_ptr(page), -1); >> + if (hpage_pincount_available(page)) >> + atomic_set(compound_pincount_ptr(page), 0); >> +} >> + >> +static void prep_compound_tail(struct page *head, int tail_idx) >> +{ >> + struct page *p = head + tail_idx; >> + >> + set_page_count(p, 0); > > When you rebase, you should notice this has been removed from > prep_compound_page as all tail pages should have zero ref count. > /me nods >> + p->mapping = TAIL_MAPPING; >> + set_compound_head(p, head); >> +} >> + >> void prep_compound_page(struct page *page, unsigned int order) >> { >> int i; >> int nr_pages = 1 << order; >> >> __SetPageHead(page); >> - for (i = 1; i < nr_pages; i++) { >> - struct page *p = page + i; >> - set_page_count(p, 0); >> - p->mapping = TAIL_MAPPING; >> - set_compound_head(p, page); >> - } >> + for (i = 1; i < nr_pages; i++) >> + prep_compound_tail(page, i); >> >> - set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); >> - set_compound_order(page, order); >> - atomic_set(compound_mapcount_ptr(page), -1); >> - if (hpage_pincount_available(page)) >> - atomic_set(compound_pincount_ptr(page), 0); >> + prep_compound_head(page, order); >> } >> >> #ifdef CONFIG_DEBUG_PAGEALLOC >> > > I'll need something like this for demote hugetlb page fuinctionality > when the pages being demoted have been optimized for minimal vmemmap > usage. > > Acked-by: Mike Kravetz <mike.kravetz@oracle.com> > Thanks!
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8836e54721ae..95967ce55829 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -741,24 +741,34 @@ void free_compound_page(struct page *page) free_the_page(page, compound_order(page)); } +static void prep_compound_head(struct page *page, unsigned int order) +{ + set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); + set_compound_order(page, order); + atomic_set(compound_mapcount_ptr(page), -1); + if (hpage_pincount_available(page)) + atomic_set(compound_pincount_ptr(page), 0); +} + +static void prep_compound_tail(struct page *head, int tail_idx) +{ + struct page *p = head + tail_idx; + + set_page_count(p, 0); + p->mapping = TAIL_MAPPING; + set_compound_head(p, head); +} + void prep_compound_page(struct page *page, unsigned int order) { int i; int nr_pages = 1 << order; __SetPageHead(page); - for (i = 1; i < nr_pages; i++) { - struct page *p = page + i; - set_page_count(p, 0); - p->mapping = TAIL_MAPPING; - set_compound_head(p, page); - } + for (i = 1; i < nr_pages; i++) + prep_compound_tail(page, i); - set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); - set_compound_order(page, order); - atomic_set(compound_mapcount_ptr(page), -1); - if (hpage_pincount_available(page)) - atomic_set(compound_pincount_ptr(page), 0); + prep_compound_head(page, order); } #ifdef CONFIG_DEBUG_PAGEALLOC
Split the utility function prep_compound_page() into head and tail counterparts, and use them accordingly. This is in preparation for sharing the storage for / deduplicating compound page metadata. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> --- mm/page_alloc.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-)