| Message ID | 20220116121822.1727633-3-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Enabling large folios for 5.17 | expand |
On Sun, Jan 16, 2022 at 12:18:12PM +0000, Matthew Wilcox (Oracle) wrote: > This shrinks filemap_free_folio() by 55 bytes in my .config; 24 bytes > from removing the VM_BUG_ON_FOLIO() and 31 bytes from unifying the > small/large folio paths. > > We could just use folio_ref_sub() here since the caller should hold a > reference (as the VM_BUG_ON_FOLIO() was asserting), but that's fragile. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > mm/filemap.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 2fd9b2f24025..afc8f5ca85ac 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -231,17 +231,15 @@ void __filemap_remove_folio(struct folio *folio, void *shadow) > void filemap_free_folio(struct address_space *mapping, struct folio *folio) > { > void (*freepage)(struct page *); > + int refs = 1; > > freepage = mapping->a_ops->freepage; > if (freepage) > freepage(&folio->page); > > - if (folio_test_large(folio) && !folio_test_hugetlb(folio)) { > - folio_ref_sub(folio, folio_nr_pages(folio)); > - VM_BUG_ON_FOLIO(folio_ref_count(folio) <= 0, folio); > - } else { > - folio_put(folio); > - } > + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) > + refs = folio_nr_pages(folio); Isn't folio_test_large() check redundant? folio_nr_pages() would return 1 for non-large folio, wouldn't it? > + folio_put_refs(folio, refs); > } > > /** > -- > 2.34.1 >
On Mon, Jan 17, 2022 at 06:56:41PM +0300, Kirill A. Shutemov wrote: > On Sun, Jan 16, 2022 at 12:18:12PM +0000, Matthew Wilcox (Oracle) wrote: > > + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) > > + refs = folio_nr_pages(folio); > > Isn't folio_test_large() check redundant? folio_nr_pages() would return 1 > for non-large folio, wouldn't it? I'm trying to avoid the function call for !hugetlb pages.
diff --git a/mm/filemap.c b/mm/filemap.c index 2fd9b2f24025..afc8f5ca85ac 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -231,17 +231,15 @@ void __filemap_remove_folio(struct folio *folio, void *shadow) void filemap_free_folio(struct address_space *mapping, struct folio *folio) { void (*freepage)(struct page *); + int refs = 1; freepage = mapping->a_ops->freepage; if (freepage) freepage(&folio->page); - if (folio_test_large(folio) && !folio_test_hugetlb(folio)) { - folio_ref_sub(folio, folio_nr_pages(folio)); - VM_BUG_ON_FOLIO(folio_ref_count(folio) <= 0, folio); - } else { - folio_put(folio); - } + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) + refs = folio_nr_pages(folio); + folio_put_refs(folio, refs); } /**
This shrinks filemap_free_folio() by 55 bytes in my .config; 24 bytes from removing the VM_BUG_ON_FOLIO() and 31 bytes from unifying the small/large folio paths. We could just use folio_ref_sub() here since the caller should hold a reference (as the VM_BUG_ON_FOLIO() was asserting), but that's fragile. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- mm/filemap.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)