On Tue, Oct 13, 2020 at 08:36:43PM +0100, Matthew Wilcox wrote:
On Tue, Oct 13, 2020 at 11:44:29AM -0700, Dan Williams wrote:
On Fri, Oct 9, 2020 at 12:52 PM ira.weiny@intel.com wrote:
From: Ira Weiny ira.weiny@intel.com
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@fluxnic.net Signed-off-by: Ira Weiny ira.weiny@intel.com
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);Why does this need a sleepable kmap? This looks like a textbook kmap_atomic() use case.
There's a lot of code of this form. Could we perhaps have:
static inline void copy_to_highpage(struct page *to, void *vfrom, unsigned int size) { char *vto = kmap_atomic(to);
memcpy(vto, vfrom, size); kunmap_atomic(vto); }
in linux/highmem.h ?
Christoph had the same idea. I'll work on it.
Ira