search for: is_zone_device_pag

...ows the + * device driver to implement its own memory management. */ void (*page_free)(struct page *page); diff --git a/include/linux/mm.h b/include/linux/mm.h index 517751310dd2..5a82037a4b26 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1093,34 +1093,6 @@ static inline bool is_zone_device_page(const struct page *page) #ifdef CONFIG_DEV_PAGEMAP_OPS void free_devmap_managed_page(struct page *page); DECLARE_STATIC_KEY_FALSE(devmap_managed_key); - -static inline bool page_is_devmap_managed(struct page *page) -{ - if (!static_branch_unlikely(&devmap_managed_key)) - return false; - if...

> diff --git a/include/linux/mm.h b/include/linux/mm.h > index 517751310dd2..5a82037a4b26 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1093,34 +1093,6 @@ static inline bool is_zone_device_page(const struct page *page) > #ifdef CONFIG_DEV_PAGEMAP_OPS > void free_devmap_managed_page(struct page *page); > DECLARE_STATIC_KEY_FALSE(devmap_managed_key); The export for devmap_managed_key can be dropped now. In fact I think we can remove devmap_managed_key entirely now - it is onl...

On 9/15/20 11:09 PM, Christoph Hellwig wrote: >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index 517751310dd2..5a82037a4b26 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -1093,34 +1093,6 @@ static inline bool is_zone_device_page(const struct page *page) >> #ifdef CONFIG_DEV_PAGEMAP_OPS >> void free_devmap_managed_page(struct page *page); >> DECLARE_STATIC_KEY_FALSE(devmap_managed_key); > > The export for devmap_managed_key can be dropped now. In fact I think > we can remove devmap_manage...

...t; + * memory management. > */ > void (*page_free)(struct page *page); > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index b2f370f0b420..2159c2477aa3 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1092,39 +1092,6 @@ static inline bool is_zone_device_page(const struct page *page) > } > #endif > > -#ifdef CONFIG_DEV_PAGEMAP_OPS > -void free_devmap_managed_page(struct page *page); > -DECLARE_STATIC_KEY_FALSE(devmap_managed_key); > - > -static inline bool page_is_devmap_managed(struct page *page) > -{ > - if (!static_...

...Hum, so the only thing this config does is short circuit here: > > static inline bool is_device_public_page(const struct page *page) > { > return IS_ENABLED(CONFIG_DEV_PAGEMAP_OPS) && > IS_ENABLED(CONFIG_DEVICE_PUBLIC) && > is_zone_device_page(page) && > page->pgmap->type == MEMORY_DEVICE_PUBLIC; > } > > Which is called all over the place.. <sigh> yes but the earlier patch: [PATCH 03/22] mm: remove hmm_devmem_add_resource Removes the only place type is set to MEMORY_DEVICE_PUBLIC. S...

...ows the device driver to implement its own + * memory management. */ void (*page_free)(struct page *page); diff --git a/include/linux/mm.h b/include/linux/mm.h index b2f370f0b420..2159c2477aa3 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1092,39 +1092,6 @@ static inline bool is_zone_device_page(const struct page *page) } #endif -#ifdef CONFIG_DEV_PAGEMAP_OPS -void free_devmap_managed_page(struct page *page); -DECLARE_STATIC_KEY_FALSE(devmap_managed_key); - -static inline bool page_is_devmap_managed(struct page *page) -{ - if (!static_branch_unlikely(&devmap_managed_key)) - retur...

...ows the device driver to implement its own + * memory management. */ void (*page_free)(struct page *page); diff --git a/include/linux/mm.h b/include/linux/mm.h index 27c64d0d7520..3d71a820ae38 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1100,39 +1100,6 @@ static inline bool is_zone_device_page(const struct page *page) } #endif -#ifdef CONFIG_DEV_PAGEMAP_OPS -void free_devmap_managed_page(struct page *page); -DECLARE_STATIC_KEY_FALSE(devmap_managed_key); - -static inline bool page_is_devmap_managed(struct page *page) -{ - if (!static_branch_unlikely(&devmap_managed_key)) - retur...

...ead() to work correctly. * - * After successful get_page_unless_zero() might follow put_page() - * which needs correct compound_head(). + * Also, ZONE_DEVICE struct pages share the compound_head field and + * need to restore the pgmap pointer before unfreezing page refcount + * in order for is_zone_device_page() to work correctly. */ - clear_compound_head(page_tail); + if (is_device_private_page(head)) { + head->pgmap->ops->page_split(head, page_tail); + pin_count = 2; + } else { + clear_compound_head(page_tail); + pin_count = 1; + } /* Finally unfreeze refcount. Additional reference...

...*/ void (*page_free)(struct page *page); diff --git a/include/linux/mm.h b/include/linux/mm.h index d6b8e30dce2e..ac848eeb2a1d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1110,14 +1110,7 @@ static inline bool page_is_devmap_managed(struct page *page) return false; if (!is_zone_device_page(page)) return false; - switch (page->pgmap->type) { - case MEMORY_DEVICE_PRIVATE: - case MEMORY_DEVICE_FS_DAX: - return true; - default: - break; - } - return false; + return page->pgmap->type == MEMORY_DEVICE_FS_DAX; } void put_devmap_managed_page(struct page *page); diff --g...

Matthew Wilcox, Ira Weiny, and others have complained that ZONE_DEVICE struct page reference counting is ugly because they are "free" when the reference count is one instead of zero. This leads to explicit checks for ZONE_DEVICE pages in places like put_page(), GUP, THP splitting, and page migration which have to adjust the expected reference count when determining if the page is

...MEMORY_DEVICE_FS_DAX: __put_devmap_managed_page(page); return true; @@ -960,12 +959,6 @@ static inline bool is_device_private_page(const struct page *page) page->pgmap->type == MEMORY_DEVICE_PRIVATE; } -static inline bool is_device_public_page(const struct page *page) -{ - return is_zone_device_page(page) && - page->pgmap->type == MEMORY_DEVICE_PUBLIC; -} - #ifdef CONFIG_PCI_P2PDMA static inline bool is_pci_p2pdma_page(const struct page *page) { @@ -998,11 +991,6 @@ static inline bool is_device_private_page(const struct page *page) return false; } -static inline bool is...

...- * FIXME support THP (transparent huge page), it is bit more complex to - * check them than regular pages, because they can be mapped with a pmd - * or with a pte (split pte mapping). - */ - if (PageCompound(page)) - return false; - /* Page from ZONE_DEVICE have one extra reference */ if (is_zone_device_page(page)) { /* @@ -2726,13 +2759,115 @@ int migrate_vma_setup(struct migrate_vma *args) } EXPORT_SYMBOL(migrate_vma_setup); +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +/* + * This code closely follows: + * do_huge_pmd_anonymous_page() + * __do_huge_pmd_anonymous_page() + * except that the page...

...; > + > + devmem = container_of(page->pgmap, struct dmirror_chunk, pagemap); > + return devmem->mdevice; > +} extra devmem var is not really needed > + > +static bool dmirror_device_is_mine(struct dmirror_device *mdevice, > + struct page *page) > +{ > + if (!is_zone_device_page(page)) > + return false; > + return page->pgmap->ops == &dmirror_devmem_ops && > + dmirror_page_to_device(page) == mdevice; > +} Use new owner stuff, right? Actually this is redunant now, the check should be just WARN_ON pageowner != self owner > +static int dm...

...cuit here: > >> > >> static inline bool is_device_public_page(const struct page *page) > >> { > >> return IS_ENABLED(CONFIG_DEV_PAGEMAP_OPS) && > >> IS_ENABLED(CONFIG_DEVICE_PUBLIC) && > >> is_zone_device_page(page) && > >> page->pgmap->type == MEMORY_DEVICE_PUBLIC; > >> } > >> > >> Which is called all over the place.. > > > > <sigh> yes but the earlier patch: > > > > [PATCH 03/22] mm: remove hmm_devmem_a...

On 3/17/20 5:59 AM, Christoph Hellwig wrote: > On Tue, Mar 17, 2020 at 09:47:55AM -0300, Jason Gunthorpe wrote: >> I've been using v7 of Ralph's tester and it is working well - it has >> DEVICE_PRIVATE support so I think it can test this flow too. Ralph are >> you able? >> >> This hunk seems trivial enough to me, can we include it now? > > I can send

This is still an RFC because after looking at the pmem/dax code some more, I realized that the ZONE_DEVICE struct pages are being inserted into the process' page tables with vmf_insert_mixed() and a zero refcount on the ZONE_DEVICE struct page. This is sort of OK because insert_pfn() increments the reference count on the pgmap which is what prevents memunmap_pages() from freeing the struct

...d you are correct, never mind Hum, so the only thing this config does is short circuit here: static inline bool is_device_public_page(const struct page *page) { return IS_ENABLED(CONFIG_DEV_PAGEMAP_OPS) && IS_ENABLED(CONFIG_DEVICE_PUBLIC) && is_zone_device_page(page) && page->pgmap->type == MEMORY_DEVICE_PUBLIC; } Which is called all over the place.. So, yes, we really don't want any distro or something to turn this on until it has a use. Reviewed-by: Jason Gunthorpe <jgg at mellanox.com> Jason

...this config does is short circuit here: >> >> static inline bool is_device_public_page(const struct page *page) >> { >> return IS_ENABLED(CONFIG_DEV_PAGEMAP_OPS) && >> IS_ENABLED(CONFIG_DEVICE_PUBLIC) && >> is_zone_device_page(page) && >> page->pgmap->type == MEMORY_DEVICE_PUBLIC; >> } >> >> Which is called all over the place.. > > <sigh> yes but the earlier patch: > > [PATCH 03/22] mm: remove hmm_devmem_add_resource > > Removes the only...

...++ b/mm/internal.h > [snip] > diff --git a/mm/swap.c b/mm/swap.c > index 0eb057141a04..93d880c6f73c 100644 > --- a/mm/swap.c > +++ b/mm/swap.c > @@ -116,12 +116,11 @@ static void __put_compound_page(struct page *page) > void __put_page(struct page *page) > { > if (is_zone_device_page(page)) { > - put_dev_pagemap(page->pgmap); > - > /* > * The page belongs to the device that created pgmap. Do > * not return it to page allocator. > */ > + free_zone_device_page(page); I really like this. Ira

...*/ void (*page_free)(struct page *page); diff --git a/include/linux/mm.h b/include/linux/mm.h index ef360fe70aaf..7a7013c57a4a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1110,14 +1110,7 @@ static inline bool page_is_devmap_managed(struct page *page) return false; if (!is_zone_device_page(page)) return false; - switch (page->pgmap->type) { - case MEMORY_DEVICE_PRIVATE: - case MEMORY_DEVICE_FS_DAX: - return true; - default: - break; - } - return false; + return page->pgmap->type == MEMORY_DEVICE_FS_DAX; } void put_devmap_managed_page(struct page *page); diff --g...