On Fri, Jun 01, 2012 at 01:22:15PM -0400, KOSAKI Motohiro wrote: > (6/1/12 10:24 AM), Nathan Zimmer wrote: >> On Thu, May 31, 2012 at 04:35:53PM -0400, KOSAKI Motohiro wrote: >>> (5/31/12 4:25 PM), Andrew Morton wrote: >>>> On Thu, 31 May 2012 16:09:15 -0400 >>>> KOSAKI Motohiro<kosaki.motohiro@xxxxxxxxx> wrote: >>>> >>>>>> --- a/mm/shmem.c >>>>>> +++ b/mm/shmem.c >>>>>> @@ -929,7 +929,7 @@ static struct page *shmem_alloc_page(gfp_t gfp, >>>>>> /* >>>>>> * alloc_page_vma() will drop the shared policy reference >>>>>> */ >>>>>> - return alloc_page_vma(gfp,&pvma, 0); >>>>>> + return alloc_page_vma(gfp,&pvma, info->node_offset<< PAGE_SHIFT ); >>>>> >>>>> 3rd argument of alloc_page_vma() is an address. This is type error. >>>> >>>> Well, it's an unsigned long... >>>> >>>> But yes, it is conceptually wrong and *looks* weird. I think we can >>>> address that by overcoming our peculair aversion to documenting our >>>> code, sigh. This? >>> >>> Sorry, no. >>> >>> addr agrument of alloc_pages_vma() have two meanings. >>> >>> 1) interleave node seed >>> 2) look-up key of shmem policy >>> >>> I think this patch break (2). shmem_get_policy(pol, addr) assume caller honor to >>> pass correct address. >> >> But the pseudo vma we generated in shmem_alloc_page the vm_ops are set to NULL. >> So get_vma_policy will return the policy provided by the pseudo vma and not reach >> the shmem_get_policy. > > yes, and it is bug source. we may need to change soon. I guess the right way is > to make vm_ops->interleave and interleave_nid uses it if povided. > If we provide vm_ops then won't shmem_get_policy get called? That would be an issue since shmem_get_policy assumes vm_file is non NULL. > btw, I don't think node_random() is good idea. it is random(pid + jiffies + cycle). > current->cpuset_mem_spread_rotor is per-thread value. but you now need per-inode > interleave offset. maybe, just inode addition is enough. Why do you need randomness? > I don't really need the randomness, the rotor should be good enough. The correct way to get that is cpuset_mem_spread_node(), yes? Also apologies for such a delay in my response. -- 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>