mm/gup: Handle page split race more efficiently

If we hit the page split race, the current code returns NULL which will
presumably trigger a retry under the mmap_lock.  This isn't necessary;
we can just retry the compound_head() lookup.  This is a very minor
optimisation of an unlikely path, but conceptually it matches (eg)
the page cache RCU-protected lookup.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: John Hubbard <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: William Kucharski <[email protected]>

0 files changed, 0 insertions, 0 deletions