kmap_atomic() has been deprecated in favor of kmap_local_page().
Therefore, replace kmap_atomic() with kmap_local_page().
kmap_atomic() is implemented like a kmap_local_page() which also
disables page-faults and preemption (the latter only in !PREEMPT_RT
kernels). The kernel virtual addresses returned by these two API are
only valid in the context of the callers (i.e., they cannot be handed to
other threads).
With kmap_local_page() the mappings are per thread and CPU local like
in kmap_atomic(); however, they can handle page-faults and can be called
from any context (including interrupts). The tasks that call
kmap_local_page() can be preempted and, when they are scheduled to run
again, the kernel virtual addresses are restored and are still valid.
The code blocks between the mappings and un-mappings don't rely on the
above-mentioned side effects of kmap_atomic(), so that mere replacements
of the old API with the new one is all that they require (i.e., there is
no need to explicitly call pagefault_disable() and/or preempt_disable()).
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Signed-off-by: Fabio M. De Francesco <fabio.maria.de.francesco@xxxxxxxxxxxxxxx>
---
mm/mempool.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/mm/mempool.c b/mm/mempool.c
index 734bcf5afbb7..b3d2084fd989 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -64,10 +64,10 @@ static void check_element(mempool_t *pool, void *element)
} else if (pool->free == mempool_free_pages) {
/* Mempools backed by page allocator */
int order = (int)(long)pool->pool_data;
- void *addr = kmap_atomic((struct page *)element);
+ void *addr = kmap_local_page((struct page *)element);
__check_element(pool, addr, 1UL << (PAGE_SHIFT + order));
- kunmap_atomic(addr);
+ kunmap_local(addr);
}
}
@@ -89,10 +89,10 @@ static void poison_element(mempool_t *pool, void *element)
} else if (pool->alloc == mempool_alloc_pages) {
/* Mempools backed by page allocator */
int order = (int)(long)pool->pool_data;
- void *addr = kmap_atomic((struct page *)element);
+ void *addr = kmap_local_page((struct page *)element);
__poison_element(addr, 1UL << (PAGE_SHIFT + order));
- kunmap_atomic(addr);
+ kunmap_local(addr);
}
}
#else /* CONFIG_DEBUG_SLAB || CONFIG_SLUB_DEBUG_ON */
--
2.42.0
