The patch titled
Subject: mm/highmem: convert memzero_page() to kmap_local_page()
has been added to the -mm tree. Its filename is
mm-highmem-convert-memzero_page-to-kmap_local_page.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-highmem-convert-memzero_page-to-kmap_local_page.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-highmem-convert-memzero_page-to-kmap_local_page.patch
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------------------------------------------------------
From: Ira Weiny <ira.weiny@xxxxxxxxx>
Subject: mm/highmem: convert memzero_page() to kmap_local_page()
The memset() does not need to be performed atomically. Use
kmap_local_page() which will improved performance for this call.
Link: https://lkml.kernel.org/r/20210309212137.2610186-3-ira.weiny@xxxxxxxxx
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Chris Mason <clm@xxxxxx>
Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/highmem.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/include/linux/highmem.h~mm-highmem-convert-memzero_page-to-kmap_local_page
+++ a/include/linux/highmem.h
@@ -334,9 +334,9 @@ static inline void memcpy_to_page(struct
static inline void memzero_page(struct page *page, size_t offset, size_t len)
{
- char *addr = kmap_atomic(page);
+ char *addr = kmap_local_page(page);
memset(addr + offset, 0, len);
- kunmap_atomic(addr);
+ kunmap_local(addr);
}
#endif /* _LINUX_HIGHMEM_H */
_
Patches currently in -mm which might be from ira.weiny@xxxxxxxxx are
iov_iter-lift-memzero_page-to-highmemh.patch
mm-highmem-convert-memzero_page-to-kmap_local_page.patch
btrfs-use-memzero_page-instead-of-open-coded-kmap-pattern.patch
mm-highmem-remove-deprecated-kmap_atomic.patch
