@@ -2270,9 +2270,9 @@ int snapshot_read_next(struct snapshot_handle *handle)
*/
void *kaddr;
- kaddr = kmap_atomic(page);
+ kaddr = kmap_local_page(page);
copy_page(buffer, kaddr);
- kunmap_atomic(kaddr);
+ kunmap_local(kaddr);
handle->buffer = buffer;
} else {
handle->buffer = page_address(page);
@@ -2561,9 +2561,9 @@ static void copy_last_highmem_page(void)
if (last_highmem_page) {
void *dst;
- dst = kmap_atomic(last_highmem_page);
+ dst = kmap_local_page(last_highmem_page);
copy_page(dst, buffer);
- kunmap_atomic(dst);
+ kunmap_local(dst);
last_highmem_page = NULL;
}
}
@@ -2881,13 +2881,13 @@ static inline void swap_two_pages_data(struct page *p1, struct page *p2,
{
void *kaddr1, *kaddr2;
- kaddr1 = kmap_atomic(p1);
- kaddr2 = kmap_atomic(p2);
+ kaddr1 = kmap_local_page(p1);
+ kaddr2 = kmap_local_page(p2);
copy_page(buf, kaddr1);
copy_page(kaddr1, kaddr2);
copy_page(kaddr2, buf);
- kunmap_atomic(kaddr2);
- kunmap_atomic(kaddr1);
+ kunmap_local(kaddr2);
+ kunmap_local(kaddr1);
}
/**
kmap_atomic() is deprecated and should be replaced with kmap_local_page() [1][2]. kmap_local_page() is faster in kernels with HIGHMEM enabled, can take page faults, and allows preemption. According to [2], this replacement is safe as long as the code between kmap_atomic() and kunmap_atomic() does not implicitly depend on disabling page faults or preemption. In all of the call sites in this patch, the only thing happening between mapping and unmapping pages is copy_page() calls, and I don't suspect they depend on disabling page faults or preemption. [1] https://lwn.net/Articles/836144/ [2] https://docs.kernel.org/mm/highmem.html#temporary-virtual-mappings Signed-off-by: David Reaver <me@davidreaver.com> --- Apologies, I tried testing a CONFIG_HIGHMEM kernel in QEMU and clearly made an error because there is an obvious typo. Any pointers to test setups for testing CONFIG_HIGHMEM in a VM would be appreciated! Here is v2 of the patch. V1 -> V2: Fix typo kmap_page_local() -> kmap_local_page() kernel/power/snapshot.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)