From: Johannes Weiner <[email protected]> Add mem_cgroup_prepare_migration() and mem_cgroup_end_migration() calls into do_huge_pmd_numa_page(), and fix mem_cgroup_prepare_migration() to account for a Transparent Huge Page correctly without bugging.
Tested-by: Zhouping Liu <[email protected]> Signed-off-by: Johannes Weiner <[email protected]> Signed-off-by: Hugh Dickins <[email protected]> --- mm/huge_memory.c | 16 ++++++++++++++++ mm/memcontrol.c | 7 +++++-- 2 files changed, 21 insertions(+), 2 deletions(-) --- mmotm/mm/huge_memory.c 2012-11-09 09:43:46.892046342 -0800 +++ linux/mm/huge_memory.c 2012-11-13 14:51:04.000321370 -0800 @@ -750,6 +750,7 @@ void do_huge_pmd_numa_page(struct mm_str unsigned int flags, pmd_t entry) { unsigned long haddr = address & HPAGE_PMD_MASK; + struct mem_cgroup *memcg = NULL; struct page *new_page = NULL; struct page *page = NULL; int node, lru; @@ -840,6 +841,14 @@ migrate: return; } + /* + * Traditional migration needs to prepare the memcg charge + * transaction early to prevent the old page from being + * uncharged when installing migration entries. Here we can + * save the potential rollback and start the charge transfer + * only when migration is already known to end successfully. + */ + mem_cgroup_prepare_migration(page, new_page, &memcg); entry = mk_pmd(new_page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); @@ -850,6 +859,12 @@ migrate: set_pmd_at(mm, haddr, pmd, entry); update_mmu_cache_pmd(vma, address, entry); page_remove_rmap(page); + /* + * Finish the charge transaction under the page table lock to + * prevent split_huge_page() from dividing up the charge + * before it's fully transferred to the new page. + */ + mem_cgroup_end_migration(memcg, page, new_page, true); spin_unlock(&mm->page_table_lock); put_page(page); /* Drop the rmap reference */ @@ -860,6 +875,7 @@ migrate: put_page(page); /* drop the LRU isolation reference */ unlock_page(new_page); + unlock_page(page); put_page(page); /* Drop the local reference */ --- mmotm/mm/memcontrol.c 2012-11-09 09:43:46.896046342 -0800 +++ linux/mm/memcontrol.c 2012-11-13 14:51:04.004321370 -0800 @@ -4186,15 +4186,18 @@ void mem_cgroup_prepare_migration(struct struct mem_cgroup **memcgp) { struct mem_cgroup *memcg = NULL; + unsigned int nr_pages = 1; struct page_cgroup *pc; enum charge_type ctype; *memcgp = NULL; - VM_BUG_ON(PageTransHuge(page)); if (mem_cgroup_disabled()) return; + if (PageTransHuge(page)) + nr_pages <<= compound_order(page); + pc = lookup_page_cgroup(page); lock_page_cgroup(pc); if (PageCgroupUsed(pc)) { @@ -4256,7 +4259,7 @@ void mem_cgroup_prepare_migration(struct * charged to the res_counter since we plan on replacing the * old one and only one page is going to be left afterwards. */ - __mem_cgroup_commit_charge(memcg, newpage, 1, ctype, false); + __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false); } /* remove redundant charge if migration failed*/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
