From: Kai Shen shenkai8@huawei.com Subject: mm/hugetlb.c: don't put_page in lock of hugetlb_lock
spinlock recursion happened when do LTP test: #!/bin/bash ./runltp -p -f hugetlb & ./runltp -p -f hugetlb & ./runltp -p -f hugetlb & ./runltp -p -f hugetlb & ./runltp -p -f hugetlb &
The dtor returned by get_compound_page_dtor in __put_compound_page may be the function of free_huge_page which will lock the hugetlb_lock, so don't put_page in lock of hugetlb_lock.
BUG: spinlock recursion on CPU#0, hugemmap05/1079 lock: hugetlb_lock+0x0/0x18, .magic: dead4ead, .owner: hugemmap05/1079, .owner_cpu: 0 Call trace: dump_backtrace+0x0/0x198 show_stack+0x24/0x30 dump_stack+0xa4/0xcc spin_dump+0x84/0xa8 do_raw_spin_lock+0xd0/0x108 _raw_spin_lock+0x20/0x30 free_huge_page+0x9c/0x260 __put_compound_page+0x44/0x50 __put_page+0x2c/0x60 alloc_surplus_huge_page.constprop.19+0xf0/0x140 hugetlb_acct_memory+0x104/0x378 hugetlb_reserve_pages+0xe0/0x250 hugetlbfs_file_mmap+0xc0/0x140 mmap_region+0x3e8/0x5b0 do_mmap+0x280/0x460 vm_mmap_pgoff+0xf4/0x128 ksys_mmap_pgoff+0xb4/0x258 __arm64_sys_mmap+0x34/0x48 el0_svc_common+0x78/0x130 el0_svc_handler+0x38/0x78 el0_svc+0x8/0xc
Link: http://lkml.kernel.org/r/b8ade452-2d6b-0372-32c2-703644032b47@huawei.com Fixes: 9980d744a0 ("mm, hugetlb: get rid of surplus page accounting tricks") Signed-off-by: Kai Shen shenkai8@huawei.com Signed-off-by: Feilong Lin linfeilong@huawei.com Reported-by: Wang Wang wangwang2@huawei.com Reviewed-by: Oscar Salvador osalvador@suse.de Reviewed-by: Mike Kravetz mike.kravetz@oracle.com Reviewed-by: Andrew Morton akpm@linux-foundation.org Acked-by: Michal Hocko mhocko@suse.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/hugetlb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/mm/hugetlb.c~mm-hugetlb-dont-put_page-in-lock-of-hugetlb_lock +++ a/mm/hugetlb.c @@ -1574,8 +1574,9 @@ static struct page *alloc_surplus_huge_p */ if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { SetPageHugeTemporary(page); + spin_unlock(&hugetlb_lock); put_page(page); - page = NULL; + return NULL; } else { h->surplus_huge_pages++; h->surplus_huge_pages_node[page_to_nid(page)]++; _