On Wed, 6 Feb 2013 12:51:03 -0800 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 6 Feb 2013 16:49:34 +0100 > Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> wrote: > > > With commit 8e72033 "thp: make MADV_HUGEPAGE check for > > mm->def_flags" the VM_NOHUGEPAGE flag may be set on s390 in > > mm->def_flags for certain processes, to prevent future thp > > mappings. This would be overwritten by do_mlockall(), which sets it > > back to 0 with an optional VM_LOCKED flag set. > > > > To fix this, instead of overwriting mm->def_flags in do_mlockall(), > > only the VM_LOCKED flag should be set or cleared. > > What are the user-visible effects here? Looking at the 274023da1e8 > changelog, I'm guessing that it might be pretty nasty - kvm breakage? Yes, though at the moment there should be no mlockall()/munlockall() involved with kvm/qemu. So currently no user-visible effects, Vivek found this while reading the do_mlockall() code, but it might be a good idea to add this to stable. Could you add a "Cc: stable@xxxxxxxxxxxxxxx # v3.7+"? Thanks, Gerald -- 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>