Re: linux-next test error: BUG: using __this_cpu_read() in preemptible code in __mod_memcg_state

Re: linux-next test error: BUG: using __this_cpu_read() in preemptible code in __mod_memcg_state

[Dmitry Vyukov]

On Mon, Mar 9, 2020 at 2:27 PM Alex Shi <alex.shi@linux.alibaba.com> wrote:
> 在 2020/3/9 下午5:56, Alex Shi 写道:
> >
> >
> > 在 2020/3/9 下午5:24, Kirill A. Shutemov 写道:
> >>> check_preemption_disabled: 3 callbacks suppressed
> >>> BUG: using __this_cpu_read() in preemptible [00000000] code: syz-fuzzer/9432
> >>> caller is __mod_memcg_state+0x27/0x1a0 mm/memcontrol.c:689
> >>> CPU: 1 PID: 9432 Comm: syz-fuzzer Not tainted 5.6.0-rc4-next-20200306-syzkaller #0
> >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> >>> Call Trace:
> >>>  __dump_stack lib/dump_stack.c:77 [inline]
> >>>  dump_stack+0x188/0x20d lib/dump_stack.c:118
> >>>  check_preemption_disabled lib/smp_processor_id.c:47 [inline]
> >>>  __this_cpu_preempt_check.cold+0x84/0x90 lib/smp_processor_id.c:64
> >>>  __mod_memcg_state+0x27/0x1a0 mm/memcontrol.c:689
> >>>  __split_huge_page mm/huge_memory.c:2575 [inline]
> >>>  split_huge_page_to_list+0x124b/0x3380 mm/huge_memory.c:2862
> >>>  split_huge_page include/linux/huge_mm.h:167 [inline]
> >> It looks like a regression due to c8cba0cc2a80 ("mm/thp: narrow lru
> >> locking").
> >
> > yes, I guess so.
>
> Yes, it is a stupid mistake to pull out lock for __mod_memcg_state which
> should be in a lock.
>
> revert this patch should be all fine, since ClearPageCompound and page_ref_inc
> later may related with lru_list valid issue in release_pges.
>
>
> Sorry for the disaster!
>
> Alex

+linux-next, Stephen for currently open linux-next build/boot failure

Hi Alex,

What's the status of this? Was the guilty patch reverted? If so,
please mark it as invalid for syzbot, otherwise it still shows up as
open bug.

Re: linux-next test error: BUG: using __this_cpu_read() in preemptible code in __mod_memcg_state

[Stephen Rothwell]

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Hi Dmitry,

On Sat, 18 Apr 2020 09:04:38 +0200 Dmitry Vyukov <dvyukov@google.com> wrote:
>
> On Mon, Mar 9, 2020 at 2:27 PM Alex Shi <alex.shi@linux.alibaba.com> wrote:
> > 在 2020/3/9 下午5:56, Alex Shi 写道:  
> > >
> > >
> > > 在 2020/3/9 下午5:24, Kirill A. Shutemov 写道:  
> > >>> check_preemption_disabled: 3 callbacks suppressed
> > >>> BUG: using __this_cpu_read() in preemptible [00000000] code: syz-fuzzer/9432
> > >>> caller is __mod_memcg_state+0x27/0x1a0 mm/memcontrol.c:689
> > >>> CPU: 1 PID: 9432 Comm: syz-fuzzer Not tainted 5.6.0-rc4-next-20200306-syzkaller #0
> > >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > >>> Call Trace:
> > >>>  __dump_stack lib/dump_stack.c:77 [inline]
> > >>>  dump_stack+0x188/0x20d lib/dump_stack.c:118
> > >>>  check_preemption_disabled lib/smp_processor_id.c:47 [inline]
> > >>>  __this_cpu_preempt_check.cold+0x84/0x90 lib/smp_processor_id.c:64
> > >>>  __mod_memcg_state+0x27/0x1a0 mm/memcontrol.c:689
> > >>>  __split_huge_page mm/huge_memory.c:2575 [inline]
> > >>>  split_huge_page_to_list+0x124b/0x3380 mm/huge_memory.c:2862
> > >>>  split_huge_page include/linux/huge_mm.h:167 [inline]  
> > >> It looks like a regression due to c8cba0cc2a80 ("mm/thp: narrow lru
> > >> locking").  
> > >
> > > yes, I guess so.  
> >
> > Yes, it is a stupid mistake to pull out lock for __mod_memcg_state which
> > should be in a lock.
> >
> > revert this patch should be all fine, since ClearPageCompound and page_ref_inc
> > later may related with lru_list valid issue in release_pges.
> >
> >
> > Sorry for the disaster!
> >
> > Alex  
> 
> +linux-next, Stephen for currently open linux-next build/boot failure
> 
> Hi Alex,
> 
> What's the status of this? Was the guilty patch reverted? If so,
> please mark it as invalid for syzbot, otherwise it still shows up as
> open bug.

The patch was removed from Andrew's tree in March and never made it to
Linus' tree.  I can't find how to tell syzbot that the patch went away ...

-- 
Cheers,
Stephen Rothwell

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Re: linux-next test error: BUG: using __this_cpu_read() in preemptible code in __mod_memcg_state

[Stephen Rothwell]

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Hi Stephen,

On Sat, 18 Apr 2020 17:43:53 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi Dmitry,
> 
> On Sat, 18 Apr 2020 09:04:38 +0200 Dmitry Vyukov <dvyukov@google.com> wrote:
> >
> > On Mon, Mar 9, 2020 at 2:27 PM Alex Shi <alex.shi@linux.alibaba.com> wrote:  
> > > 在 2020/3/9 下午5:56, Alex Shi 写道:    
> > > >
> > > >
> > > > 在 2020/3/9 下午5:24, Kirill A. Shutemov 写道:    
> > > >>> check_preemption_disabled: 3 callbacks suppressed
> > > >>> BUG: using __this_cpu_read() in preemptible [00000000] code: syz-fuzzer/9432
> > > >>> caller is __mod_memcg_state+0x27/0x1a0 mm/memcontrol.c:689
> > > >>> CPU: 1 PID: 9432 Comm: syz-fuzzer Not tainted 5.6.0-rc4-next-20200306-syzkaller #0
> > > >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > > >>> Call Trace:
> > > >>>  __dump_stack lib/dump_stack.c:77 [inline]
> > > >>>  dump_stack+0x188/0x20d lib/dump_stack.c:118
> > > >>>  check_preemption_disabled lib/smp_processor_id.c:47 [inline]
> > > >>>  __this_cpu_preempt_check.cold+0x84/0x90 lib/smp_processor_id.c:64
> > > >>>  __mod_memcg_state+0x27/0x1a0 mm/memcontrol.c:689
> > > >>>  __split_huge_page mm/huge_memory.c:2575 [inline]
> > > >>>  split_huge_page_to_list+0x124b/0x3380 mm/huge_memory.c:2862
> > > >>>  split_huge_page include/linux/huge_mm.h:167 [inline]    
> > > >> It looks like a regression due to c8cba0cc2a80 ("mm/thp: narrow lru
> > > >> locking").    
> > > >
> > > > yes, I guess so.    
> > >
> > > Yes, it is a stupid mistake to pull out lock for __mod_memcg_state which
> > > should be in a lock.
> > >
> > > revert this patch should be all fine, since ClearPageCompound and page_ref_inc
> > > later may related with lru_list valid issue in release_pges.
> > >
> > >
> > > Sorry for the disaster!
> > >
> > > Alex    
> > 
> > +linux-next, Stephen for currently open linux-next build/boot failure
> > 
> > Hi Alex,
> > 
> > What's the status of this? Was the guilty patch reverted? If so,
> > please mark it as invalid for syzbot, otherwise it still shows up as
> > open bug.  
> 
> The patch was removed from Andrew's tree in March and never made it to
> Linus' tree.  I can't find how to tell syzbot that the patch went away ...

Lets try:

#syz invalid

-- 
Cheers,
Stephen Rothwell

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Re: linux-next test error: BUG: using __this_cpu_read() in preemptible code in __mod_memcg_state

[Dmitry Vyukov]

On Sat, Apr 18, 2020 at 9:51 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi Stephen,
>
> On Sat, 18 Apr 2020 17:43:53 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > Hi Dmitry,
> >
> > On Sat, 18 Apr 2020 09:04:38 +0200 Dmitry Vyukov <dvyukov@google.com> wrote:
> > >
> > > On Mon, Mar 9, 2020 at 2:27 PM Alex Shi <alex.shi@linux.alibaba.com> wrote:
> > > > 在 2020/3/9 下午5:56, Alex Shi 写道:
> > > > >
> > > > >
> > > > > 在 2020/3/9 下午5:24, Kirill A. Shutemov 写道:
> > > > >>> check_preemption_disabled: 3 callbacks suppressed
> > > > >>> BUG: using __this_cpu_read() in preemptible [00000000] code: syz-fuzzer/9432
> > > > >>> caller is __mod_memcg_state+0x27/0x1a0 mm/memcontrol.c:689
> > > > >>> CPU: 1 PID: 9432 Comm: syz-fuzzer Not tainted 5.6.0-rc4-next-20200306-syzkaller #0
> > > > >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > > > >>> Call Trace:
> > > > >>>  __dump_stack lib/dump_stack.c:77 [inline]
> > > > >>>  dump_stack+0x188/0x20d lib/dump_stack.c:118
> > > > >>>  check_preemption_disabled lib/smp_processor_id.c:47 [inline]
> > > > >>>  __this_cpu_preempt_check.cold+0x84/0x90 lib/smp_processor_id.c:64
> > > > >>>  __mod_memcg_state+0x27/0x1a0 mm/memcontrol.c:689
> > > > >>>  __split_huge_page mm/huge_memory.c:2575 [inline]
> > > > >>>  split_huge_page_to_list+0x124b/0x3380 mm/huge_memory.c:2862
> > > > >>>  split_huge_page include/linux/huge_mm.h:167 [inline]
> > > > >> It looks like a regression due to c8cba0cc2a80 ("mm/thp: narrow lru
> > > > >> locking").
> > > > >
> > > > > yes, I guess so.
> > > >
> > > > Yes, it is a stupid mistake to pull out lock for __mod_memcg_state which
> > > > should be in a lock.
> > > >
> > > > revert this patch should be all fine, since ClearPageCompound and page_ref_inc
> > > > later may related with lru_list valid issue in release_pges.
> > > >
> > > >
> > > > Sorry for the disaster!
> > > >
> > > > Alex
> > >
> > > +linux-next, Stephen for currently open linux-next build/boot failure
> > >
> > > Hi Alex,
> > >
> > > What's the status of this? Was the guilty patch reverted? If so,
> > > please mark it as invalid for syzbot, otherwise it still shows up as
> > > open bug.
> >
> > The patch was removed from Andrew's tree in March and never made it to
> > Linus' tree.  I can't find how to tell syzbot that the patch went away ...
>
> Lets try:
>
> #syz invalid

This is correct, thanks!

You may now see "Status: closed as invalid on 2020/04/18 07:51" at:
https://syzkaller.appspot.com/bug?extid=826543256ed3b8c37f62

It does not show up as "open" and if this will happen again syzbot
will report it (rather than assume it's still the old bug happening).

Re: linux-next test error: BUG: using __this_cpu_read() in preemptible code in __mod_memcg_state

[Stephen Rothwell]

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Hi Dmitry,

On Sat, 18 Apr 2020 10:02:36 +0200 Dmitry Vyukov <dvyukov@google.com> wrote:
> >
> > #syz invalid  
> 
> This is correct, thanks!
> 
> You may now see "Status: closed as invalid on 2020/04/18 07:51" at:
> https://syzkaller.appspot.com/bug?extid=826543256ed3b8c37f62
> 
> It does not show up as "open" and if this will happen again syzbot
> will report it (rather than assume it's still the old bug happening).

OK, good, thanks.

-- 
Cheers,
Stephen Rothwell

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