将page的flags转换为可读字符串
crash> kmem -g 01fffe00000a001c FLAGS: 1fffe00000a001c PAGE-FLAG BIT VALUE PG_referenced 2 0000004 PG_uptodate 3 0000008 PG_dirty 4 0000010 PG_reclaim 17 0020000 PG_unevictable 19 0080000 PG_savepinned 4 0000010 PG_isolated 17 0020000
此外，可以用whatis查看pageflags的定义:
crash> whatis pageflags enum pageflags { PG_locked = 0 PG_error = 1 PG_referenced = 2 PG_uptodate = 3 PG_dirty = 4 PG_lru = 5 PG_active = 6 PG_waiters = 7 PG_slab = 8 PG_owner_priv_1 = 9 PG_arch_1 = 10 PG_reserved = 11 PG_private = 12 PG_private_2 = 13 PG_writeback = 14 PG_head = 15 PG_mappedtodisk = 16 PG_reclaim = 17 PG_swapbacked = 18 PG_unevictable = 19 PG_mlocked = 20 PG_uncached = 21 PG_hwpoison = 22 PG_young = 23 PG_idle = 24 PG_workingset = 25 __NR_PAGEFLAGS = 26 PG_checked = 9 PG_swapcache = 9 PG_fscache = 13 PG_pinned = 9 PG_savepinned = 4 PG_foreign = 9 PG_slob_free = 12 PG_double_map = 13 PG_isolated = 17 };
上面__NR_PAGEFLAGS表示flags中前26位用于表示page的状态，所以在转换时会忽略标志位的无效位。
将vma的flags转换为可读的字符
crash> vm -f 8000875 8000875: (READ|EXEC|MAYREAD|MAYWRITE|MAYEXEC|DENYWRITE|CAN_NONLINEAR)
