diff options
Diffstat (limited to 'arch/x86/mm/init_64.c')
| -rw-r--r-- | arch/x86/mm/init_64.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 36a017b4a30d..7c4f6f591f2b 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -959,9 +959,18 @@ int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages, ret = __add_pages(nid, start_pfn, nr_pages, params); WARN_ON_ONCE(ret); - /* update max_pfn, max_low_pfn and high_memory */ - update_end_of_memory_vars(start_pfn << PAGE_SHIFT, - nr_pages << PAGE_SHIFT); + /* + * Special case: add_pages() is called by memremap_pages() for adding device + * private pages. Do not bump up max_pfn in the device private path, + * because max_pfn changes affect dma_addressing_limited(). + * + * dma_addressing_limited() returning true when max_pfn is the device's + * addressable memory can force device drivers to use bounce buffers + * and impact their performance negatively: + */ + if (!params->pgmap) + /* update max_pfn, max_low_pfn and high_memory */ + update_end_of_memory_vars(start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT); return ret; } |