On Mon, Sep 16, 2013 at 8:18 PM, Wanpeng Li <liw...@linux.vnet.ibm.com> wrote: > Hi KOSAKI, > On Mon, Sep 16, 2013 at 05:23:32PM -0400, KOSAKI Motohiro wrote: >>On 9/14/2013 7:45 PM, Wanpeng Li wrote: >>> Changelog: >>> *v2 -> v3: revert commit d157a558 directly >>> >>> The VM_UNINITIALIZED/VM_UNLIST flag introduced by commit f5252e00(mm: avoid >>> null pointer access in vm_struct via /proc/vmallocinfo) is used to avoid >>> accessing the pages field with unallocated page when show_numa_info() is >>> called. This patch move the check just before show_numa_info in order that >>> some messages still can be dumped via /proc/vmallocinfo. This patch revert >>> commit d157a558 (mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead >>> of show_numa_info); >> >>Both d157a558 and your patch don't explain why your one is better. Yes, some >>messages _can_ be dumped. But why should we do so? > > More messages can be dumped and original commit f5252e00(mm: avoid null > pointer > access in vm_struct via /proc/vmallocinfo) do that. > >>And No. __get_vm_area_node() doesn't use __GFP_ZERO for allocating >>vm_area_struct. >>dumped partial dump is not only partial, but also may be garbage. > > vm_struct is allocated by kzalloc_node.
Oops, you are right. Then, your code _intentionally_ show amazing zero. Heh, nice. More message is pointless. zero is just zero. It doesn't have any information. >>I wonder why we need to call setup_vmalloc_vm() _after_ insert_vmap_area. > > I think it's another topic. Why? > Fill vm_struct and set VM_VM_AREA flag. If I misunderstand your > question? VM_VM_AREA doesn't help. we have race between insert_vmap_area and setup_vmalloc_vm. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
