| Message ID | 20230821202016.2910321-4-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Convert perf ringbuffer to folios | expand |
在 2023/8/22 4:20, Matthew Wilcox (Oracle) 写道: > Eliminate a use of page->mapping by using vmalloc_to_folio() instead. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > include/linux/mm.h | 5 +++++ > kernel/events/ring_buffer.c | 4 ++-- > 2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 840bae5f23b6..7d84a2843193 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1134,6 +1134,11 @@ int region_intersects(resource_size_t offset, size_t size, unsigned long flags, > struct page *vmalloc_to_page(const void *addr); > unsigned long vmalloc_to_pfn(const void *addr); > > +static inline struct folio *vmalloc_to_folio(const void *addr) > +{ > + return page_folio(vmalloc_to_page(addr)); > +} Thanks a lot. This function is very wonderful. It is also what I need. Zhu Yanjun > + > /* > * Determine if an address is within the vmalloc range > * > diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c > index c73add132618..56939dc3bf33 100644 > --- a/kernel/events/ring_buffer.c > +++ b/kernel/events/ring_buffer.c > @@ -873,9 +873,9 @@ __perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff) > > static void perf_mmap_unmark_page(void *addr) > { > - struct page *page = vmalloc_to_page(addr); > + struct folio *folio = vmalloc_to_folio(addr); > > - page->mapping = NULL; > + folio->mapping = NULL; > } > > static void rb_free_work(struct work_struct *work)
On 8/22/23 04:20, Matthew Wilcox (Oracle) wrote: > Eliminate a use of page->mapping by using vmalloc_to_folio() instead. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > include/linux/mm.h | 5 +++++ > kernel/events/ring_buffer.c | 4 ++-- > 2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 840bae5f23b6..7d84a2843193 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1134,6 +1134,11 @@ int region_intersects(resource_size_t offset, size_t size, unsigned long flags, > struct page *vmalloc_to_page(const void *addr); > unsigned long vmalloc_to_pfn(const void *addr); > > +static inline struct folio *vmalloc_to_folio(const void *addr) > +{ > + return page_folio(vmalloc_to_page(addr)); I am wondering whether we should check the return value of vmalloc_to_page()? > +} > + > /* > * Determine if an address is within the vmalloc range > * > diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c > index c73add132618..56939dc3bf33 100644 > --- a/kernel/events/ring_buffer.c > +++ b/kernel/events/ring_buffer.c > @@ -873,9 +873,9 @@ __perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff) > > static void perf_mmap_unmark_page(void *addr) > { > - struct page *page = vmalloc_to_page(addr); > + struct folio *folio = vmalloc_to_folio(addr); > > - page->mapping = NULL; > + folio->mapping = NULL; > } > > static void rb_free_work(struct work_struct *work)
On Wed, Aug 23, 2023 at 03:30:22PM +0800, Yin Fengwei wrote: > On 8/22/23 04:20, Matthew Wilcox (Oracle) wrote: > > +static inline struct folio *vmalloc_to_folio(const void *addr) > > +{ > > + return page_folio(vmalloc_to_page(addr)); > I am wondering whether we should check the return value of vmalloc_to_page()? That's a good question. Almost every user of vmalloc_to_page() just assumes it works. But it'll cost very little to check for NULL, so I'll put that into the next version. Thanks!
On Mon, Aug 21, 2023 at 09:20:15PM +0100, Matthew Wilcox (Oracle) wrote: > Eliminate a use of page->mapping by using vmalloc_to_folio() instead. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > include/linux/mm.h | 5 +++++ > kernel/events/ring_buffer.c | 4 ++-- > 2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 840bae5f23b6..7d84a2843193 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1134,6 +1134,11 @@ int region_intersects(resource_size_t offset, size_t size, unsigned long flags, > struct page *vmalloc_to_page(const void *addr); > unsigned long vmalloc_to_pfn(const void *addr); > > +static inline struct folio *vmalloc_to_folio(const void *addr) > +{ > + return page_folio(vmalloc_to_page(addr)); > +} > + Total nit, and quite possibly unnecessary, but it might be nice to have a comment pointing out that vmalloc_to_page can and will return tail pages hence the need for page_folio() and thus _compound_head(). This makes me wonder about a typedef or wrapper type which explicitly indicates that a function is _intentionally_ returning something that might be a head or a tail page. But perhaps once foliofication is complete, this is what struct page or its memdesc replacement will become? > /* > * Determine if an address is within the vmalloc range > * > diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c > index c73add132618..56939dc3bf33 100644 > --- a/kernel/events/ring_buffer.c > +++ b/kernel/events/ring_buffer.c > @@ -873,9 +873,9 @@ __perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff) > > static void perf_mmap_unmark_page(void *addr) > { > - struct page *page = vmalloc_to_page(addr); > + struct folio *folio = vmalloc_to_folio(addr); > > - page->mapping = NULL; > + folio->mapping = NULL; > } > > static void rb_free_work(struct work_struct *work) > -- > 2.40.1 > Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
diff --git a/include/linux/mm.h b/include/linux/mm.h index 840bae5f23b6..7d84a2843193 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1134,6 +1134,11 @@ int region_intersects(resource_size_t offset, size_t size, unsigned long flags, struct page *vmalloc_to_page(const void *addr); unsigned long vmalloc_to_pfn(const void *addr); +static inline struct folio *vmalloc_to_folio(const void *addr) +{ + return page_folio(vmalloc_to_page(addr)); +} + /* * Determine if an address is within the vmalloc range * diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index c73add132618..56939dc3bf33 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -873,9 +873,9 @@ __perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff) static void perf_mmap_unmark_page(void *addr) { - struct page *page = vmalloc_to_page(addr); + struct folio *folio = vmalloc_to_folio(addr); - page->mapping = NULL; + folio->mapping = NULL; } static void rb_free_work(struct work_struct *work)
Eliminate a use of page->mapping by using vmalloc_to_folio() instead. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- include/linux/mm.h | 5 +++++ kernel/events/ring_buffer.c | 4 ++-- 2 files changed, 7 insertions(+), 2 deletions(-)