Re: [PATCH 0/2] memcg: add the soft_limit reclaim in global direct reclaim

[Minchan Kim <minchan.kim@gmail.com>]

On Fri, Apr 29, 2011 at 11:58:34AM -0700, Ying Han wrote:
> On Fri, Apr 29, 2011 at 10:19 AM, Ying Han <yinghan@google.com> wrote:
> > On Fri, Apr 29, 2011 at 9:44 AM, Minchan Kim <minchan.kim@gmail.com> wrote:
> >> Hi Ying,
> >>
> >> On Thu, Apr 28, 2011 at 03:37:04PM -0700, Ying Han wrote:
> >>> We recently added the change in global background reclaim which counts the
> >>> return value of soft_limit reclaim. Now this patch adds the similar logic
> >>> on global direct reclaim.
> >>>
> >>> We should skip scanning global LRU on shrink_zone if soft_limit reclaim does
> >>> enough work. This is the first step where we start with counting the nr_scanned
> >>> and nr_reclaimed from soft_limit reclaim into global scan_control.
> >>>
> >>> The patch is based on mmotm-04-14 and i triggered kernel BUG at mm/vmscan.c:1058!
> >>
> >> Could you tell me exact patches?
> >> mmtom-04-14 + just 2 patch of this? or + something?
> >>
> >> These day, You and Kame produces many patches.
> >> Do I have to apply something of them?
> > No, I applied my patch on top of mmotm and here is the last commit
> > before my patch.
> >
> > commit 66a3827927351e0f88dc391919cf0cda10d42dd7
> > Author: Andrew Morton <akpm@linux-foundation.org>
> > Date:   Thu Apr 14 15:51:34 2011 -0700
> >
> >>
> >>>
> >>> [  938.242033] kernel BUG at mm/vmscan.c:1058!
> >>> [  938.242033] invalid opcode: 0000 [#1] SMP.
> >>> [  938.242033] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.2/device
> >>> [  938.242033] Pid: 546, comm: kswapd0 Tainted: G        W   2.6.39-smp-direct_reclaim
> >>> [  938.242033] RIP: 0010:[<ffffffff810ed174>]  [<ffffffff810ed174>] isolate_pages_global+0x18c/0x34f
> >>> [  938.242033] RSP: 0018:ffff88082f83bb50  EFLAGS: 00010082
> >>> [  938.242033] RAX: 00000000ffffffea RBX: ffff88082f83bc90 RCX: 0000000000000401
> >>> [  938.242033] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffea001ca653e8
> >>> [  938.242033] RBP: ffff88082f83bc20 R08: 0000000000000000 R09: ffff88085ffb6e00
> >>> [  938.242033] R10: ffff88085ffb73d0 R11: ffff88085ffb6e00 R12: ffff88085ffb6e00
> >>> [  938.242033] R13: ffffea001ca65410 R14: 0000000000000001 R15: ffffea001ca653e8
> >>> [  938.242033] FS:  0000000000000000(0000) GS:ffff88085fd00000(0000) knlGS:0000000000000000
> >>> [  938.242033] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> >>> [  938.242033] CR2: 00007f5c3405c320 CR3: 0000000001803000 CR4: 00000000000006e0
> >>> [  938.242033] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> >>> [  938.242033] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> >>> [  938.242033] Process kswapd0 (pid: 546, threadinfo ffff88082f83a000, task ffff88082fe52080)
> >>> [  938.242033] Stack:
> >>> [  938.242033]  ffff88085ffb6e00 ffffea0000000002 0000000000000021 0000000000000000
> >>> [  938.242033]  0000000000000000 ffff88082f83bcb8 ffffea00108eec80 ffffea00108eecb8
> >>> [  938.242033]  ffffea00108eecf0 0000000000000004 fffffffffffffffc 0000000000000020
> >>> [  938.242033] Call Trace:
> >>> [  938.242033]  [<ffffffff810ee8a5>] shrink_inactive_list+0x185/0x418
> >>> [  938.242033]  [<ffffffff810366cc>] ? __switch_to+0xea/0x212
> >>> [  938.242033]  [<ffffffff810e8b35>] ? determine_dirtyable_memory+0x1a/0x2c
> >>> [  938.242033]  [<ffffffff810ef19b>] shrink_zone+0x380/0x44d
> >>> [  938.242033]  [<ffffffff810e5188>] ? zone_watermark_ok_safe+0xa1/0xae
> >>> [  938.242033]  [<ffffffff810efbd8>] kswapd+0x41b/0x76b
> >>> [  938.242033]  [<ffffffff810ef7bd>] ? zone_reclaim+0x2fb/0x2fb
> >>> [  938.242033]  [<ffffffff81088569>] kthread+0x82/0x8a
> >>> [  938.242033]  [<ffffffff8141b0d4>] kernel_thread_helper+0x4/0x10
> >>> [  938.242033]  [<ffffffff810884e7>] ? kthread_worker_fn+0x112/0x112
> >>> [  938.242033]  [<ffffffff8141b0d0>] ? gs_change+0xb/0xb
> >>>
> >>
> >> It seems there is active page in inactive list.
> >> As I look deactivate_page, lru_deactivate_fn clears PageActive before
> >> add_page_to_lru_list and it should be protected by zone->lru_lock.
> >> In addiion, PageLRU would protect with race with isolation functions.
> >>
> >> Hmm, I don't have any clue now.
> >> Is it reproducible easily?
> > I can manage to reproduce it on my host by adding lots of memory
> > pressure and then trigger the global
> > reclaim.
> >
> >>
> >> Could you apply below debugging patch and report the result?
> >>
> >> diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
> >> index 8f7d247..f39b53a 100644
> >> --- a/include/linux/mm_inline.h
> >> +++ b/include/linux/mm_inline.h
> >> @@ -25,6 +25,8 @@ static inline void
> >>  __add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l,
> >>                       struct list_head *head)
> >>  {
> >> +       VM_BUG_ON(PageActive(page) && (
> >> +                       l == LRU_INACTIVE_ANON || l == LRU_INACTIVE_FILE));
> >>        list_add(&page->lru, head);
> >>        __mod_zone_page_state(zone, NR_LRU_BASE + l, hpage_nr_pages(page));
> >>        mem_cgroup_add_lru_list(page, l);
> >> diff --git a/mm/swap.c b/mm/swap.c
> >> index a83ec5a..5f7c3c8 100644
> >> --- a/mm/swap.c
> >> +++ b/mm/swap.c
> >> @@ -454,6 +454,8 @@ static void lru_deactivate_fn(struct page *page, void *arg)
> >>                 * The page's writeback ends up during pagevec
> >>                 * We moves tha page into tail of inactive.
> >>                 */
> >> +               VM_BUG_ON(PageActive(page) && (
> >> +                       lru == LRU_INACTIVE_ANON || lru == LRU_INACTIVE_FILE));
> >>                list_move_tail(&page->lru, &zone->lru[lru].list);
> >>                mem_cgroup_rotate_reclaimable_page(page);
> >>                __count_vm_event(PGROTATED);
> >> diff --git a/mm/vmscan.c b/mm/vmscan.c
> >> index b3a569f..3415896 100644
> >> --- a/mm/vmscan.c
> >> +++ b/mm/vmscan.c
> >> @@ -963,7 +963,7 @@ int __isolate_lru_page(struct page *page, int mode, int file)
> >>
> >>        /* Only take pages on the LRU. */
> >>        if (!PageLRU(page))
> >> -               return ret;
> >> +               return 1;
> >>
> >>        /*
> >>         * When checking the active state, we need to be sure we are
> >> @@ -971,10 +971,10 @@ int __isolate_lru_page(struct page *page, int mode, int file)
> >>         * of each.
> >>         */
> >>        if (mode != ISOLATE_BOTH && (!PageActive(page) != !mode))
> >> -               return ret;
> >> +               return 2;
> >>
> >>        if (mode != ISOLATE_BOTH && page_is_file_cache(page) != file)
> >> -               return ret;
> >> +               return 3;
> >>
> >>        /*
> >>         * When this function is being called for lumpy reclaim, we
> >> @@ -982,7 +982,7 @@ int __isolate_lru_page(struct page *page, int mode, int file)
> >>         * unevictable; only give shrink_page_list evictable pages.
> >>         */
> >>        if (PageUnevictable(page))
> >> -               return ret;
> >> +               return 4;
> >>
> >>        ret = -EBUSY;
> >>
> >> @@ -1035,13 +1035,14 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
> >>                unsigned long end_pfn;
> >>                unsigned long page_pfn;
> >>                int zone_id;
> >> +               int ret;
> >>
> >>                page = lru_to_page(src);
> >>                prefetchw_prev_lru_page(page, src, flags);
> >>
> >>                VM_BUG_ON(!PageLRU(page));
> >>
> >> -               switch (__isolate_lru_page(page, mode, file)) {
> >> +               switch (ret = __isolate_lru_page(page, mode, file)) {
> >>                case 0:
> >>                        list_move(&page->lru, dst);
> >>                        mem_cgroup_del_lru(page);
> >> @@ -1055,6 +1056,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
> >>                        continue;
> >>
> >>                default:
> >> +                       printk(KERN_ERR "ret %d\n", ret);
> >>                        BUG();
> >>                }
> >>
> >>> Thank you Minchan for the pointer. I reverted the following commit and I
> >>> haven't seen the problem with the same operation. I haven't looked deeply
> >>> on the patch yet, but figured it would be a good idea to post the dump.
> >>> The dump looks not directly related to this patchset, but ppl can use it to
> >>> reproduce the problem.
> >>
> >> I tested the patch with rsync + fadvise several times
> >> in my machine(2P, 2G DRAM) but I didn't have ever seen the BUG.
> >> But I didn't test it in memcg. As I look dump, it seems not related to memcg.
> >> Anyway, I tried it to reproduce it in my machine.
> >> Maybe I will start testing after next week. Sorry.
> >>
> >> I hope my debugging patch givse some clues.
> >> Thanks for the reporting, Ying.
> >
> > Sure, i will try the patch and post the result.
> 
> Minchan:
> 
> Here is the stack trace after applying your patch. We used
> trace_printk instead since the printk doesn't give me the message. The
> ret == 4 , so looks like we are failing at the check  if
> (PageUnevictable(page))
> 
> kernel is based on tag: mmotm-2011-04-14-15-08 plus my the two memcg
> patches in the thread, and also the debugging patch.
> 
> [  426.696004] kernel BUG at mm/vmscan.c:1061!
> [  426.696004] invalid opcode: 0000 [#1] SMP.
> [  426.696004] Dumping ftrace buffer:
> [  426.696004] ---------------------------------
> [  426.696004]    <...>-546     4d... 426442418us : isolate_pages_global: ret 4
> [  426.696004] ---------------------------------
> [  426.696004] RIP: 0010:[<ffffffff810ed1b2>]  [<ffffffff810ed1b2>]
> isolate_pages_global+0x1ba/0x37d
> [  426.696004] RSP: 0000:ffff88082f8dfb50  EFLAGS: 00010086
> [  426.696004] RAX: 0000000000000001 RBX: ffff88082f8dfc90 RCX: 0000000000000000
> [  426.696004] RDX: 0000000000000006 RSI: 0000000000000046 RDI: ffff88085f805f80
> [  426.696004] RBP: ffff88082f8dfc20 R08: 0000000000000000 R09: 0000000000000007
> [  426.696004] R10: 0000000000000005 R11: 0000000000000000 R12: ffff88085ffb6e00
> [  426.696004] R13: ffffea001ca66c58 R14: 0000000000000004 R15: ffffea001ca66c30
> [  426.696004] FS:  0000000000000000(0000) GS:ffff88085fd00000(0000)
> knlGS:0000000000000000
> [  426.696004] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  426.696004] CR2: 00007f0c65c6f320 CR3: 000000082b66f000 CR4: 00000000000006e0
> [  426.696004] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [  426.696004] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> [  426.696004] Process kswapd0 (pid: 546, threadinfo ffff88082f8de000,
> task ffff88082f83b8e0)
> [  426.696004] Stack:
> [  426.696004]  ffff88085ffb6e00 ffffea0000000002 0000000000000020
> 0000000000000000
> [  426.696004]  0000000000000000 ffff88082f8dfcb8 ffffea00158f58d8
> ffffea00158f5868
> [  426.696004]  ffffea00158f5de0 0000000000000001 ffffffffffffffff
> 0000000000000020
> [  426.696004] Call Trace:
> [  426.696004]  [<ffffffff810ee8e7>] shrink_inactive_list+0x185/0x3c9
> [  426.696004]  [<ffffffff8107a3fc>] ? lock_timer_base+0x2c/0x52
> [  426.696004]  [<ffffffff810e8b2d>] ? determine_dirtyable_memory+0x1a/0x2c
> [  426.696004]  [<ffffffff810ef17c>] shrink_zone+0x380/0x44d
> [  426.696004]  [<ffffffff810e5180>] ? zone_watermark_ok_safe+0xa1/0xae
> [  426.696004]  [<ffffffff810efbb9>] kswapd+0x41b/0x76b
> [  426.696004]  [<ffffffff810ef79e>] ? zone_reclaim+0x2fb/0x2fb
> [  426.696004]  [<ffffffff81088561>] kthread+0x82/0x8a
> [  426.696004]  [<ffffffff8141af54>] kernel_thread_helper+0x4/0x10
> [  426.696004]  [<ffffffff810884df>] ? kthread_worker_fn+0x112/0x112
> [  426.696004]  [<ffffffff8141af50>] ? gs_change+0xb/0xb
> [  426.696004] Code: 01 00 00 89 c6 48 c7 c7 69 52 70 81 31 c0 e8 c1
> 46 32 00 48 8b 35 37 2b 79 00 44 89 f2 48 c7 c7 8a d1 0e 81 31 c0 e8
> 09 e2 fd ff <0f> 0b eb fe 49 8b 45 d8 48 b9 00 00 00 00 00 16 00 00 4c
> 8b 75.
> [  426.696004] RIP  [<ffffffff810ed1b2>] isolate_pages_global+0x1ba/0x37d
> [  426.696004]  RSP <ffff88082f8dfb50>
> [  426.696004] ---[ end trace fbb25b41a0373361 ]---
> [  426.696004] Kernel panic - not syncing: Fatal exception
> [  426.696004] Pid: 546, comm: kswapd0 Tainted: G      D W
> 2.6.39-smp-Minchan #28
> [  426.696004] Call Trace:
> [  426.696004]  [<ffffffff81411758>] panic+0x91/0x194
> [  426.696004]  [<ffffffff81414708>] oops_end+0xae/0xbe
> [  426.696004]  [<ffffffff81039906>] die+0x5a/0x63
> [  426.696004]  [<ffffffff814141a1>] do_trap+0x121/0x130
> [  426.696004]  [<ffffffff81037e85>] do_invalid_op+0x96/0x9f
> [  426.696004]  [<ffffffff810ed1b2>] ? isolate_pages_global+0x1ba/0x37d
> [  426.696004]  [<ffffffff810c414a>] ? ring_buffer_lock_reserve+0x6a/0x78
> [  426.696004]  [<ffffffff810c2e3e>] ? rb_commit+0x76/0x78
> [  426.696004]  [<ffffffff810c2eab>] ? ring_buffer_unlock_commit+0x21/0x25
> [  426.696004]  [<ffffffff8141add5>] invalid_op+0x15/0x20
> [  426.696004]  [<ffffffff810ed1b2>] ? isolate_pages_global+0x1ba/0x37d
> [  426.696004]  [<ffffffff810ee8e7>] shrink_inactive_list+0x185/0x3c9
> [  426.696004]  [<ffffffff8107a3fc>] ? lock_timer_base+0x2c/0x52
> [  426.696004]  [<ffffffff810e8b2d>] ? determine_dirtyable_memory+0x1a/0x2c
> [  426.696004]  [<ffffffff810ef17c>] shrink_zone+0x380/0x44d
> [  426.696004]  [<ffffffff810e5180>] ? zone_watermark_ok_safe+0xa1/0xae
> [  426.696004]  [<ffffffff810efbb9>] kswapd+0x41b/0x76b
> [  426.696004]  [<ffffffff810ef79e>] ? zone_reclaim+0x2fb/0x2fb
> [  426.696004]  [<ffffffff81088561>] kthread+0x82/0x8a
> [  426.696004]  [<ffffffff8141af54>] kernel_thread_helper+0x4/0x10
> [  426.696004]  [<ffffffff810884df>] ? kthread_worker_fn+0x112/0x112
> [  426.696004]  [<ffffffff8141af50>] ? gs_change+0xb/0xb
> 
> --Ying

Thanks for the testing.
I missed mprotect case in your scenario.
Yes. I didn't test it at that time. :(
So, it wasn't related to your patch and memcg.
The mprotect makes many unevictable page and it seems my deactive_page could move
it into inactive list. Totally, it's my fault. 
Could you test below patch?