On Tue, 2014-03-11 at 15:39 -0400, Sasha Levin wrote: > Hi all, > > I've ended up deleting the log file by mistake, but this bug does seem to be important > so I'd rather not wait before the same issue is triggered again. > > The call chain is: > > mlock (mm/mlock.c:745) > __mm_populate (mm/mlock.c:700) > __mlock_vma_pages_range (mm/mlock.c:229) > VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem)); So __mm_populate() is only called by mlock(2) and this VM_BUG_ON seems wrong as we call it without the lock held: up_write(¤t->mm->mmap_sem); if (!error) error = __mm_populate(start, len, 0); return error; } > > It seems to be a rather simple trace triggered from userspace. The only recent patch > in the area (that I've noticed) was "mm/mlock: prepare params outside critical region". > I've reverted it and trying to testing without it. Odd, this patch should definitely *not* cause this. In any case every operation removed from the critical region is local to the function: lock_limit = rlimit(RLIMIT_MEMLOCK); lock_limit >>= PAGE_SHIFT; locked = len >> PAGE_SHIFT; down_write(¤t->mm->mmap_sem); -- 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>