diff options
| author | David Reaver <me@davidreaver.com> | 2025-01-12 07:26:55 -0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-02-18 20:39:24 +0100 |
| commit | d42044aad6528e0c9533dbaf836d1b0fbb19fe2d (patch) | |
| tree | 0fa890031566f3911761307370aed21f28dbb4ff | |
| parent | 0ad2507d5d93f39619fc42372c347d6006b64319 (diff) | |
PM: hibernate: Replace deprecated kmap_atomic() with kmap_local_page()
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.
Link: https://lwn.net/Articles/836144/ [1]
Link: https://docs.kernel.org/mm/highmem.html#temporary-virtual-mappings [2]
Signed-off-by: David Reaver <me@davidreaver.com>
Link: https://patch.msgid.link/20250112152658.20132-1-me@davidreaver.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | kernel/power/snapshot.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index c9fb559a6399..4e6e24e8b854 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -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); } /** |