mm/rmap: extend rmap_walk_xxx() to cope with different cases
There are a lot of common parts in traversing functions, but there are
also a little of uncommon parts in it. By assigning proper function
pointer on each rmap_walker_control, we can handle these difference
correctly.
Following are differences we should handle.
1. difference of lock function in anon mapping case
2. nonlinear handling in file mapping case
3. prechecked condition:
checking memcg in page_referenced(),
checking VM_SHARE in page_mkclean()
checking temporary vma in try_to_unmap()
4. exit condition:
checking page_mapped() in try_to_unmap()
So, in this patch, I introduce 4 function pointers to handle above
differences.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 6a456ce..616aa4d 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -235,10 +235,25 @@
void page_unlock_anon_vma_read(struct anon_vma *anon_vma);
int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
+/*
+ * rmap_walk_control: To control rmap traversing for specific needs
+ *
+ * arg: passed to rmap_one() and invalid_vma()
+ * rmap_one: executed on each vma where page is mapped
+ * done: for checking traversing termination condition
+ * file_nonlinear: for handling file nonlinear mapping
+ * anon_lock: for getting anon_lock by optimized way rather than default
+ * invalid_vma: for skipping uninterested vma
+ */
struct rmap_walk_control {
void *arg;
int (*rmap_one)(struct page *page, struct vm_area_struct *vma,
unsigned long addr, void *arg);
+ int (*done)(struct page *page);
+ int (*file_nonlinear)(struct page *, struct address_space *,
+ struct vm_area_struct *vma);
+ struct anon_vma *(*anon_lock)(struct page *page);
+ bool (*invalid_vma)(struct vm_area_struct *vma, void *arg);
};
/*