On Sun, Nov 26, 2017 at 07:33:56PM +0200, Jarkko Sakkinen wrote: > > +struct sgx_encl_page { > > + unsigned long addr; > > + unsigned int flags; > > + void *epc_page; > > + struct sgx_va_page *va_page; > > + unsigned int va_offset; > > + struct list_head list; > > +}; > > This can be without major streches hoops packed way more. There are 12 > bits free for use in the addr field. I can use low three bits for flags > and upper nine bits for va_offset. > > I think I can also quite easily union epc_page and va_page fields. > > With these changes the struct would shrink to: > > struct sgx_encl_page { > unsigned long addr; > union { > void *epc_page; > struct sgx_va_page *va_page; > }; > struct list_head list; > }; Once I started to thinking more about this I realized that this can be shrunk even further. I can drop the list field and use a tag for loaded pages in the radix tree where these are stored. The end result would be struct sgx_encl_page { unsigned long addr; union { void *epc_page; struct sgx_va_page *va_page; }; }; /Jarkko