| Message ID | 20180223144807.1180-4-igor.stoppa@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Feb 23, 2018 at 04:48:03PM +0200, Igor Stoppa wrote: > @@ -1769,6 +1771,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, > > kmemleak_vmalloc(area, size, gfp_mask); > > + for (i = 0; i < area->nr_pages; i++) > + area->pages[i]->area = area; > + > return addr; > > fail: IMO, this is the wrong place to initialise the page->area. It should be done in __vmalloc_area_node() like so: area->nr_pages = i; goto fail; } + page->area = area; area->pages[i] = page; if (gfpflags_allow_blocking(gfp_mask)) cond_resched();
On 25/02/18 05:38, Matthew Wilcox wrote: > On Fri, Feb 23, 2018 at 04:48:03PM +0200, Igor Stoppa wrote: >> @@ -1769,6 +1771,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, >> >> kmemleak_vmalloc(area, size, gfp_mask); >> >> + for (i = 0; i < area->nr_pages; i++) >> + area->pages[i]->area = area; >> + >> return addr; >> >> fail: > > IMO, this is the wrong place to initialise the page->area. It should be > done in __vmalloc_area_node() like so: > > area->nr_pages = i; > goto fail; > } > + page->area = area; > area->pages[i] = page; > if (gfpflags_allow_blocking(gfp_mask)) > cond_resched(); > ok -- igor
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 673942094328..14d99ed22397 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); } @@ -1744,6 +1745,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, const void *caller) { struct vm_struct *area; + unsigned int i; void *addr; unsigned long real_size = size; @@ -1769,6 +1771,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, kmemleak_vmalloc(area, size, gfp_mask); + for (i = 0; i < area->nr_pages; i++) + area->pages[i]->area = area; + return addr; fail:
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 | 5 +++++ 2 files changed, 6 insertions(+)