Message ID | 20210527230809.3701-6-Felix.Kuehling@amd.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | Support DEVICE_GENERIC memory in migrate_vma_* | expand |
On Thu, May 27, 2021 at 07:08:09PM -0400, Felix Kuehling wrote: > From: Alex Sierra <alex.sierra@amd.com> > > pages in device mapping refcounts are 1-based, instead > of 0-based. If refcount 1, means it can be freed. > This logic is not set for Generic memory type. Therefore, > its release is threated as a normal page, instead of > the callback device driver release it. So we really need to stop this magic one off refcount. We had a WIP patchset to do that, and we need to finish that off instad of piling on more hacks.
Am 2021-05-29 um 2:42 a.m. schrieb Christoph Hellwig: > On Thu, May 27, 2021 at 07:08:09PM -0400, Felix Kuehling wrote: >> From: Alex Sierra <alex.sierra@amd.com> >> >> pages in device mapping refcounts are 1-based, instead >> of 0-based. If refcount 1, means it can be freed. >> This logic is not set for Generic memory type. Therefore, >> its release is threated as a normal page, instead of >> the callback device driver release it. > So we really need to stop this magic one off refcount. We had a WIP > patchset to do that, and we need to finish that off instad of piling on > more hacks. Sure. I'll be happy to help with that, if I can. Thanks, Felix
diff --git a/include/linux/mm.h b/include/linux/mm.h index 1af7b9b76948..83bd2f3e111b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1130,6 +1130,7 @@ static inline bool page_is_devmap_managed(struct page *page) switch (page->pgmap->type) { case MEMORY_DEVICE_PRIVATE: case MEMORY_DEVICE_FS_DAX: + case MEMORY_DEVICE_GENERIC: return true; default: break; diff --git a/mm/memremap.c b/mm/memremap.c index 16b2fb482da1..d2563fbcf987 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -44,6 +44,7 @@ EXPORT_SYMBOL(devmap_managed_key); static void devmap_managed_enable_put(struct dev_pagemap *pgmap) { if (pgmap->type == MEMORY_DEVICE_PRIVATE || + pgmap->type == MEMORY_DEVICE_GENERIC || pgmap->type == MEMORY_DEVICE_FS_DAX) static_branch_dec(&devmap_managed_key); } @@ -51,6 +52,7 @@ static void devmap_managed_enable_put(struct dev_pagemap *pgmap) static void devmap_managed_enable_get(struct dev_pagemap *pgmap) { if (pgmap->type == MEMORY_DEVICE_PRIVATE || + pgmap->type == MEMORY_DEVICE_GENERIC || pgmap->type == MEMORY_DEVICE_FS_DAX) static_branch_inc(&devmap_managed_key); } @@ -480,7 +482,8 @@ EXPORT_SYMBOL_GPL(get_dev_pagemap); void free_devmap_managed_page(struct page *page) { /* notify page idle for dax */ - if (!is_device_private_page(page)) { + if (!(is_device_private_page(page) || + is_device_generic_page(page))) { wake_up_var(&page->_refcount); return; }