On Fri, Aug 02, 2019 at 09:49:02PM -0700, Arnd Bergmann wrote: > ARM64 randdconfig builds regularly run into a build error, especially > when NUMA_BALANCING and SPARSEMEM are enabled but not SPARSEMEM_VMEMMAP: > > #error "KASAN: not enough bits in page flags for tag" > > The last-cpuid bits are already contitional on the available space, so > the result of the calculation is a bit random on whether they were > already left out or not. > > Adding the kasan tag bits before last-cpuid makes it much more likely to > end up with a successful build here, and should be reliable for > randconfig at least, as long as that does not randomize NR_CPUS or > NODES_SHIFT but uses the defaults. > > In order for the modified check to not trigger in the x86 vdso32 code > where all constants are wrong (building with -m32), enclose all the > definitions with an #ifdef. >
This results in ./include/linux/page-flags-layout.h:95:2: error: #error "Not enough bits in page flags" #error "Not enough bits in page flags" when trying to build mipsel64:fuloong2e_defconfig. Guenter
