On Mon, Jan 23, 2023 at 05:30:07PM +0000, David Howells wrote: > Renumber FOLL_PIN and FOLL_GET down to bit 0 and 1 respectively so that > they are coincidentally the same as BIO_PAGE_PINNED and BIO_PAGE_REFFED and > also so that they can be stored in the bottom two bits of a page pointer > (something I'm looking at for zerocopy socket fragments). > > (Note that BIO_PAGE_REFFED should probably be got rid of at some point, > hence why FOLL_PIN is at 0.) > > Also renumber down the other FOLL_* flags to close the gaps. Taking the risk of having a long bikeshed: I much prefer (1U << bitnr) style definition that make it obvious where there are holes, but otherwise: Reviewed-by: Christoph Hellwig <hch@xxxxxx>