On Wed, Nov 22, 2017 at 11:11:36AM +0530, Aneesh Kumar K.V wrote: > "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> writes: > > > With 5-level paging, we have 56-bit virtual address space available for > > userspace. But we don't want to expose userspace to addresses above > > 47-bits, unless it asked specifically for it. > > > > We use mmap(2) hint address as a way for kernel to know if it's okay to > > allocate virtual memory above 47-bit. > > > > Let's add a self-test that covers few corner cases of the interface. > > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > > Can we move this to selftest/vm/ ? I had a variant which i was using to > test issues on ppc64. One change we did recently was to use >=128TB as > the hint addr value to select larger address space. I also would like to > check for exact mmap return addr in some case. Attaching below the test > i was using. I will check whether this patch can be updated to test what > is converted in my selftest. I also want to do the boundary check twice. > The hash trasnslation mode in POWER require us to track addr limit and > we had bugs around address space slection before and after updating the > addr limit. Feel free to move it to selftest/vm. I don't have time to test setup and test it on Power myself, but this would be great. -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
