| Message ID | 20221130220803.3657490-2-willy@infradead.org (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Split page pools from struct page | expand |
On 30/11/2022 23.07, Matthew Wilcox (Oracle) wrote: > As part of simplifying struct page, create a new netmem type which > mirrors the page_pool members in struct page. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > include/net/page_pool.h | 41 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 41 insertions(+) > > diff --git a/include/net/page_pool.h b/include/net/page_pool.h > index 813c93499f20..af6ff8c302a0 100644 > --- a/include/net/page_pool.h > +++ b/include/net/page_pool.h > @@ -50,6 +50,47 @@ > PP_FLAG_DMA_SYNC_DEV |\ > PP_FLAG_PAGE_FRAG) > > +/* page_pool used by netstack */ Can we improve the comment, making in more clear that this netmem struct is mirroring/sharing/using part of struct page? My proposal: /* page_pool used by netstack mirrors/uses members in struct page */ > +struct netmem { > + unsigned long flags; /* Page flags */ > + /** > + * @pp_magic: magic value to avoid recycling non > + * page_pool allocated pages. > + */ > + unsigned long pp_magic; > + struct page_pool *pp; > + unsigned long _pp_mapping_pad; > + unsigned long dma_addr; > + union { > + /** > + * dma_addr_upper: might require a 64-bit > + * value on 32-bit architectures. > + */ > + unsigned long dma_addr_upper; > + /** > + * For frag page support, not supported in > + * 32-bit architectures with 64-bit DMA. > + */ > + atomic_long_t pp_frag_count; > + }; > + atomic_t _mapcount; > + atomic_t _refcount; > +}; > + > +#define NETMEM_MATCH(pg, nm) \ > + static_assert(offsetof(struct page, pg) == offsetof(struct netmem, nm)) > +NETMEM_MATCH(flags, flags); > +NETMEM_MATCH(lru, pp_magic); > +NETMEM_MATCH(pp, pp); > +NETMEM_MATCH(mapping, _pp_mapping_pad); > +NETMEM_MATCH(dma_addr, dma_addr); > +NETMEM_MATCH(dma_addr_upper, dma_addr_upper); > +NETMEM_MATCH(pp_frag_count, pp_frag_count); > +NETMEM_MATCH(_mapcount, _mapcount); > +NETMEM_MATCH(_refcount, _refcount); > +#undef NETMEM_MATCH > +static_assert(sizeof(struct netmem) <= sizeof(struct page)); > + > /* > * Fast allocation side cache array/stack > *
diff --git a/include/net/page_pool.h b/include/net/page_pool.h index 813c93499f20..af6ff8c302a0 100644 --- a/include/net/page_pool.h +++ b/include/net/page_pool.h @@ -50,6 +50,47 @@ PP_FLAG_DMA_SYNC_DEV |\ PP_FLAG_PAGE_FRAG) +/* page_pool used by netstack */ +struct netmem { + unsigned long flags; /* Page flags */ + /** + * @pp_magic: magic value to avoid recycling non + * page_pool allocated pages. + */ + unsigned long pp_magic; + struct page_pool *pp; + unsigned long _pp_mapping_pad; + unsigned long dma_addr; + union { + /** + * dma_addr_upper: might require a 64-bit + * value on 32-bit architectures. + */ + unsigned long dma_addr_upper; + /** + * For frag page support, not supported in + * 32-bit architectures with 64-bit DMA. + */ + atomic_long_t pp_frag_count; + }; + atomic_t _mapcount; + atomic_t _refcount; +}; + +#define NETMEM_MATCH(pg, nm) \ + static_assert(offsetof(struct page, pg) == offsetof(struct netmem, nm)) +NETMEM_MATCH(flags, flags); +NETMEM_MATCH(lru, pp_magic); +NETMEM_MATCH(pp, pp); +NETMEM_MATCH(mapping, _pp_mapping_pad); +NETMEM_MATCH(dma_addr, dma_addr); +NETMEM_MATCH(dma_addr_upper, dma_addr_upper); +NETMEM_MATCH(pp_frag_count, pp_frag_count); +NETMEM_MATCH(_mapcount, _mapcount); +NETMEM_MATCH(_refcount, _refcount); +#undef NETMEM_MATCH +static_assert(sizeof(struct netmem) <= sizeof(struct page)); + /* * Fast allocation side cache array/stack *
As part of simplifying struct page, create a new netmem type which mirrors the page_pool members in struct page. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- include/net/page_pool.h | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+)