Messages in this thread | | | Date | Mon, 29 Oct 2012 10:44:50 +0800 | From | Zhouping Liu <> | Subject | Re: [PATCH 00/31] numa/core patches |
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On 10/29/2012 01:56 AM, Johannes Weiner wrote: > On Fri, Oct 26, 2012 at 11:08:00AM +0200, Peter Zijlstra wrote: >> On Fri, 2012-10-26 at 17:07 +0800, Zhouping Liu wrote: >>> [ 180.918591] RIP: 0010:[<ffffffff8118c39a>] [<ffffffff8118c39a>] mem_cgroup_prepare_migration+0xba/0xd0 >>> [ 182.681450] [<ffffffff81183b60>] do_huge_pmd_numa_page+0x180/0x500 >>> [ 182.775090] [<ffffffff811585c9>] handle_mm_fault+0x1e9/0x360 >>> [ 182.863038] [<ffffffff81632b62>] __do_page_fault+0x172/0x4e0 >>> [ 182.950574] [<ffffffff8101c283>] ? __switch_to_xtra+0x163/0x1a0 >>> [ 183.041512] [<ffffffff8101281e>] ? __switch_to+0x3ce/0x4a0 >>> [ 183.126832] [<ffffffff8162d686>] ? __schedule+0x3c6/0x7a0 >>> [ 183.211216] [<ffffffff81632ede>] do_page_fault+0xe/0x10 >>> [ 183.293705] [<ffffffff8162f518>] page_fault+0x28/0x30 >> Johannes, this looks like the thp migration memcg hookery gone bad, >> could you have a look at this? > Oops. Here is an incremental fix, feel free to fold it into #31.
Hi Johannes,
Tested the below patch, and I'm sure it has fixed the above issue, thank you.
Zhouping
> > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> > --- > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 5c30a14..0d7ebd3 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -801,8 +801,6 @@ void do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, > if (!new_page) > goto alloc_fail; > > - mem_cgroup_prepare_migration(page, new_page, &memcg); > - > lru = PageLRU(page); > > if (lru && isolate_lru_page(page)) /* does an implicit get_page() */ > @@ -835,6 +833,14 @@ void do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, > > 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); > @@ -845,6 +851,12 @@ void do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, > 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 */ > @@ -856,18 +868,14 @@ void do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, > > unlock_page(new_page); > > - mem_cgroup_end_migration(memcg, page, new_page, true); > - > unlock_page(page); > put_page(page); /* Drop the local reference */ > > return; > > alloc_fail: > - if (new_page) { > - mem_cgroup_end_migration(memcg, page, new_page, false); > + if (new_page) > put_page(new_page); > - } > > unlock_page(page); > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 7acf43b..011e510 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -3255,15 +3255,18 @@ void mem_cgroup_prepare_migration(struct page *page, struct page *newpage, > 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)) { > @@ -3325,7 +3328,7 @@ void mem_cgroup_prepare_migration(struct page *page, struct page *newpage, > * 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*/
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