The patch titled
Subject: mm/migrate: fix refcount handling when !hugepage_migration_supported()
has been removed from the -mm tree. Its filename was
mm-migrate-fix-ref-count-handling-when-hugepage_migration_supported-v2.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Punit Agrawal <punit.agrawal@xxxxxxx>
Subject: mm/migrate: fix refcount handling when !hugepage_migration_supported()
On failing to migrate a page, soft_offline_huge_page() performs the
necessary update to the hugepage ref-count. When
!hugepage_migration_supported() , unmap_and_move_hugepage() also
decrements the page ref-count for the hugepage. The combined behaviour
leaves the ref-count in an inconsistent state.
This leads to soft lockups when running the overcommitted hugepage test
from mce-tests suite.
Soft offlining pfn 0x83ed600 at process virtual address 0x400000000000
soft offline: 0x83ed600: migration failed 1, type
1fffc00000008008 (uptodate|head)
INFO: rcu_preempt detected stalls on CPUs/tasks:
Tasks blocked on level-0 rcu_node (CPUs 0-7): P2715
(detected by 7, t=5254 jiffies, g=963, c=962, q=321)
thugetlb_overco R running task 0 2715 2685 0x00000008
Call trace:
[<ffff000008089f90>] dump_backtrace+0x0/0x268
[<ffff00000808a2d4>] show_stack+0x24/0x30
[<ffff000008100d34>] sched_show_task+0x134/0x180
[<ffff0000081c90fc>] rcu_print_detail_task_stall_rnp+0x54/0x7c
[<ffff00000813cfd4>] rcu_check_callbacks+0xa74/0xb08
[<ffff000008143a3c>] update_process_times+0x34/0x60
[<ffff0000081550e8>] tick_sched_handle.isra.7+0x38/0x70
[<ffff00000815516c>] tick_sched_timer+0x4c/0x98
[<ffff0000081442e0>] __hrtimer_run_queues+0xc0/0x300
[<ffff000008144fa4>] hrtimer_interrupt+0xac/0x228
[<ffff0000089a56d4>] arch_timer_handler_phys+0x3c/0x50
[<ffff00000812f1bc>] handle_percpu_devid_irq+0x8c/0x290
[<ffff0000081297fc>] generic_handle_irq+0x34/0x50
[<ffff000008129f00>] __handle_domain_irq+0x68/0xc0
[<ffff0000080816b4>] gic_handle_irq+0x5c/0xb0
Address this by changing the putback_active_hugepage() in
soft_offline_huge_page() to putback_movable_pages().
This only triggers on systems that enable memory failure handling
(ARCH_SUPPORTS_MEMORY_FAILURE) but not hugepage migration
(!ARCH_ENABLE_HUGEPAGE_MIGRATION).
I imagine this wasn't triggered as there aren't many systems running this
configuration.
[akpm@xxxxxxxxxxxxxxxxxxxx: remove dead comment, per Naoya]
Link: http://lkml.kernel.org/r/20170525135146.32011-1-punit.agrawal@xxxxxxx
Reported-by: Manoj Iyer <manoj.iyer@xxxxxxxxxxxxx>
Tested-by: Manoj Iyer <manoj.iyer@xxxxxxxxxxxxx>
Suggested-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [3.14+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff -puN mm/memory-failure.c~mm-migrate-fix-ref-count-handling-when-hugepage_migration_supported-v2 mm/memory-failure.c
--- a/mm/memory-failure.c~mm-migrate-fix-ref-count-handling-when-hugepage_migration_supported-v2
+++ a/mm/memory-failure.c
@@ -1595,12 +1595,8 @@ static int soft_offline_huge_page(struct
if (ret) {
pr_info("soft offline: %#lx: migration failed %d, type %lx (%pGp)\n",
pfn, ret, page->flags, &page->flags);
- /*
- * We know that soft_offline_huge_page() tries to migrate
- * only one hugepage pointed to by hpage, so we need not
- * run through the pagelist here.
- */
- putback_active_hugepage(hpage);
+ if (!list_empty(&pagelist))
+ putback_movable_pages(&pagelist);
if (ret > 0)
ret = -EIO;
} else {
_
Patches currently in -mm which might be from punit.agrawal@xxxxxxx are
mm-gup-ensure-real-head-page-is-ref-counted-when-using-hugepages.patch
mm-hugetlb-add-size-parameter-to-huge_pte_offset.patch
mm-hugetlb-allow-architectures-to-override-huge_pte_clear.patch
mm-hugetlb-introduce-set_huge_swap_pte_at-helper.patch
mm-hugetlb-introduce-set_huge_swap_pte_at-helper-v4.patch
mm-hugetlb-introduce-set_huge_swap_pte_at-helper-v41.patch
mm-rmap-use-correct-helper-when-poisoning-hugepages.patch
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