On Fri, 9 Oct 2020, ira.weiny@xxxxxxxxx wrote:
> From: Ira Weiny <ira.weiny@xxxxxxxxx>
>
> 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: Nicolas Pitre <nico@xxxxxxxxxxx>
> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Acked-by: Nicolas Pitre <nico@xxxxxxxxxxx>
> fs/cramfs/inode.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
> index 912308600d39..003c014a42ed 100644
> --- a/fs/cramfs/inode.c
> +++ b/fs/cramfs/inode.c
> @@ -247,8 +247,8 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset,
> struct page *page = pages[i];
>
> if (page) {
> - memcpy(data, kmap(page), PAGE_SIZE);
> - kunmap(page);
> + memcpy(data, kmap_thread(page), PAGE_SIZE);
> + kunmap_thread(page);
> put_page(page);
> } else
> memset(data, 0, PAGE_SIZE);
> @@ -826,7 +826,7 @@ static int cramfs_readpage(struct file *file, struct page *page)
>
> maxblock = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
> bytes_filled = 0;
> - pgdata = kmap(page);
> + pgdata = kmap_thread(page);
>
> if (page->index < maxblock) {
> struct super_block *sb = inode->i_sb;
> @@ -914,13 +914,13 @@ static int cramfs_readpage(struct file *file, struct page *page)
>
> memset(pgdata + bytes_filled, 0, PAGE_SIZE - bytes_filled);
> flush_dcache_page(page);
> - kunmap(page);
> + kunmap_thread(page);
> SetPageUptodate(page);
> unlock_page(page);
> return 0;
>
> err:
> - kunmap(page);
> + kunmap_thread(page);
> ClearPageUptodate(page);
> SetPageError(page);
> unlock_page(page);
> --
> 2.28.0.rc0.12.gb6a658bd00c9
>
>
