Re: [PATCH RFC PKS/PMEM 22/58] fs/f2fs: Utilize new kmap_thread()
From: Eric Biggers <ebiggers@kernel.org>
Date: 2020-10-09 21:35:27
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On Fri, Oct 09, 2020 at 12:49:57PM -0700, ira.weiny@intel.com wrote:
quoted hunk ↗ jump to hunk
From: Ira Weiny <redacted> The kmap() calls in this FS are localized to a single thread. To avoid the over head of global PKRS updates use the new kmap_thread() call. Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Chao Yu <chao@kernel.org> Signed-off-by: Ira Weiny <redacted> --- fs/f2fs/f2fs.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index d9e52a7f3702..ff72a45a577e 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h@@ -2410,12 +2410,12 @@ static inline struct page *f2fs_pagecache_get_page( static inline void f2fs_copy_page(struct page *src, struct page *dst) { - char *src_kaddr = kmap(src); - char *dst_kaddr = kmap(dst); + char *src_kaddr = kmap_thread(src); + char *dst_kaddr = kmap_thread(dst); memcpy(dst_kaddr, src_kaddr, PAGE_SIZE); - kunmap(dst); - kunmap(src); + kunmap_thread(dst); + kunmap_thread(src); }
Wouldn't it make more sense to switch cases like this to kmap_atomic()? The pages are only mapped to do a memcpy(), then they're immediately unmapped. - Eric