On Sun, Jan 02, 2022 at 09:57:17PM +0000, Matthew Wilcox (Oracle) wrote: > This replaces try_get_compound_head(). It includes a small optimisation > for the race where a folio is split between being looked up from its > tail page and the reference count being obtained. Before, it returned > NULL, which presumably triggered a retry under the mmap_lock, whereas > now it will retry without the lock. Finding a frozen page will still > return NULL. Looks good: Reviewed-by: Christoph Hellwig <hch@xxxxxx> Although I think splitting out the rety optimization into a separate patch would be nicer to document the change and to ease bisection if that arises.
