| Message ID | 20230106215251.599222-1-sidhartha.kumar@oracle.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [mm-unstable] mm: introduce folio_is_pfmemalloc | expand |
On Fri, Jan 06, 2023 at 03:52:51PM -0600, Sidhartha Kumar wrote: > Add a folio equivalent for page_is_pfmemalloc. This removes two instances > of page_is_pfmemalloc(folio_page(folio, 0)) so the folio can be used > directly. > > Suggested-by: Matthew Wilcox <willy@infradead.org> > Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Hi Sidhartha, On Fri, 6 Jan 2023 15:52:51 -0600 Sidhartha Kumar <sidhartha.kumar@oracle.com> wrote: > Add a folio equivalent for page_is_pfmemalloc. This removes two instances > of page_is_pfmemalloc(folio_page(folio, 0)) so the folio can be used > directly. > > Suggested-by: Matthew Wilcox <willy@infradead.org> > Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: SeongJae Park <sj@kernel.org> Thanks, SJ > --- > include/linux/mm.h | 15 +++++++++++++++ > mm/slab.c | 2 +- > mm/slub.c | 2 +- > 3 files changed, 17 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index c37f9330f14e..79d5a0cbf4c3 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1906,6 +1906,21 @@ static inline bool page_is_pfmemalloc(const struct page *page) > return (uintptr_t)page->lru.next & BIT(1); > } > > +/* > + * Return true only if the folio has been allocated with > + * ALLOC_NO_WATERMARKS and the low watermark was not > + * met implying that the system is under some pressure. > + */ > +static inline bool folio_is_pfmemalloc(const struct folio *folio) > +{ > + /* > + * lru.next has bit 1 set if the page is allocated from the > + * pfmemalloc reserves. Callers may simply overwrite it if > + * they do not need to preserve that information. > + */ > + return (uintptr_t)folio->lru.next & BIT(1); > +} > + > /* > * Only to be called by the page allocator on a freshly allocated > * page. > diff --git a/mm/slab.c b/mm/slab.c > index 7a269db050ee..01291ecbc0d8 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -1373,7 +1373,7 @@ static struct slab *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, > /* Make the flag visible before any changes to folio->mapping */ > smp_wmb(); > /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ > - if (sk_memalloc_socks() && page_is_pfmemalloc(folio_page(folio, 0))) > + if (sk_memalloc_socks() && folio_is_pfmemalloc(folio)) > slab_set_pfmemalloc(slab); > > return slab; > diff --git a/mm/slub.c b/mm/slub.c > index 13459c69095a..0cbe6eff23fa 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -1859,7 +1859,7 @@ static inline struct slab *alloc_slab_page(gfp_t flags, int node, > __folio_set_slab(folio); > /* Make the flag visible before any changes to folio->mapping */ > smp_wmb(); > - if (page_is_pfmemalloc(folio_page(folio, 0))) > + if (folio_is_pfmemalloc(folio)) > slab_set_pfmemalloc(slab); > > return slab; > -- > 2.39.0 > >
On 1/6/23 22:52, Sidhartha Kumar wrote: > Add a folio equivalent for page_is_pfmemalloc. This removes two instances > of page_is_pfmemalloc(folio_page(folio, 0)) so the folio can be used > directly. > > Suggested-by: Matthew Wilcox <willy@infradead.org> > Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
diff --git a/include/linux/mm.h b/include/linux/mm.h index c37f9330f14e..79d5a0cbf4c3 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1906,6 +1906,21 @@ static inline bool page_is_pfmemalloc(const struct page *page) return (uintptr_t)page->lru.next & BIT(1); } +/* + * Return true only if the folio has been allocated with + * ALLOC_NO_WATERMARKS and the low watermark was not + * met implying that the system is under some pressure. + */ +static inline bool folio_is_pfmemalloc(const struct folio *folio) +{ + /* + * lru.next has bit 1 set if the page is allocated from the + * pfmemalloc reserves. Callers may simply overwrite it if + * they do not need to preserve that information. + */ + return (uintptr_t)folio->lru.next & BIT(1); +} + /* * Only to be called by the page allocator on a freshly allocated * page. diff --git a/mm/slab.c b/mm/slab.c index 7a269db050ee..01291ecbc0d8 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1373,7 +1373,7 @@ static struct slab *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, /* Make the flag visible before any changes to folio->mapping */ smp_wmb(); /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ - if (sk_memalloc_socks() && page_is_pfmemalloc(folio_page(folio, 0))) + if (sk_memalloc_socks() && folio_is_pfmemalloc(folio)) slab_set_pfmemalloc(slab); return slab; diff --git a/mm/slub.c b/mm/slub.c index 13459c69095a..0cbe6eff23fa 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1859,7 +1859,7 @@ static inline struct slab *alloc_slab_page(gfp_t flags, int node, __folio_set_slab(folio); /* Make the flag visible before any changes to folio->mapping */ smp_wmb(); - if (page_is_pfmemalloc(folio_page(folio, 0))) + if (folio_is_pfmemalloc(folio)) slab_set_pfmemalloc(slab); return slab;
Add a folio equivalent for page_is_pfmemalloc. This removes two instances of page_is_pfmemalloc(folio_page(folio, 0)) so the folio can be used directly. Suggested-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> --- include/linux/mm.h | 15 +++++++++++++++ mm/slab.c | 2 +- mm/slub.c | 2 +- 3 files changed, 17 insertions(+), 2 deletions(-)