Messages in this thread Patch in this message | | | From | Igor Stoppa <> | Subject | [PATCH 4/8] struct page: add field for vm_struct | Date | Tue, 13 Mar 2018 23:45:50 +0200 |
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When a page is used for virtual memory, it is often necessary to obtain a handler to the corresponding vm_struct, which refers to the virtually continuous area generated when invoking vmalloc.
The struct page has a "mapping" field, which can be re-used, to store a pointer to the parent area.
This will avoid more expensive searches, later on.
Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com> --- include/linux/mm_types.h | 1 + mm/vmalloc.c | 2 ++ 2 files changed, 3 insertions(+)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index fd1af6b9591d..c3a4825e10c0 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -84,6 +84,7 @@ struct page { void *s_mem; /* slab first object */ atomic_t compound_mapcount; /* first tail page */ /* page_deferred_list().next -- second tail page */ + struct vm_struct *area; }; /* Second double word */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index ebff729cc956..61a1ca22b0f6 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1536,6 +1536,7 @@ static void __vunmap(const void *addr, int deallocate_pages) struct page *page = area->pages[i]; BUG_ON(!page); + page->area = NULL; __free_pages(page, 0); } @@ -1705,6 +1706,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, area->nr_pages = i; goto fail; } + page->area = area; area->pages[i] = page; if (gfpflags_allow_blocking(gfp_mask|highmem_mask)) cond_resched(); -- 2.14.1
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