Michal Hocko <mhocko@xxxxxxx> writes: > On Tue 26-03-13 16:59:40, Aneesh Kumar K.V wrote: >> Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> writes: > [...] >> > diff --git v3.9-rc3.orig/mm/memory-failure.c v3.9-rc3/mm/memory-failure.c >> > index df0694c..4e01082 100644 >> > --- v3.9-rc3.orig/mm/memory-failure.c >> > +++ v3.9-rc3/mm/memory-failure.c >> > @@ -1467,6 +1467,7 @@ static int soft_offline_huge_page(struct page *page, int flags) >> > int ret; >> > unsigned long pfn = page_to_pfn(page); >> > struct page *hpage = compound_head(page); >> > + LIST_HEAD(pagelist); >> > >> > /* >> > * This double-check of PageHWPoison is to avoid the race with >> > @@ -1482,12 +1483,20 @@ static int soft_offline_huge_page(struct page *page, int flags) >> > unlock_page(hpage); >> > >> > /* Keep page count to indicate a given hugepage is isolated. */ >> > - ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, >> > - MIGRATE_SYNC); >> > - put_page(hpage); >> > + list_move(&hpage->lru, &pagelist); >> >> we use hpage->lru to add the hpage to h->hugepage_activelist. This will >> break a hugetlb cgroup removal isn't it ? > > This particular part will not break removal because > hugetlb_cgroup_css_offline loops until hugetlb_cgroup_have_usage is 0. > > Little bit offtopic: > Btw. hugetlb migration breaks to charging even before this patchset > AFAICS. The above put_page should remove the last reference and then it > will uncharge it but I do not see anything that would charge a new page. > This is all because regula LRU pages are uncharged when they are > unmapped. But this a different story not related to this series. But when we call that put_page, we would have alreayd move the cgroup information to the new page. We have h_cg = hugetlb_cgroup_from_page(oldhpage); set_hugetlb_cgroup(oldhpage, NULL); /* move the h_cg details to new cgroup */ set_hugetlb_cgroup(newhpage, h_cg); in hugetlb_cgroup_migrate -aneesh -- 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>