FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

[gregkh]

The patch below does not apply to the 5.7-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From da97f2d56bbd880b4138916a7ef96f9881a551b2 Mon Sep 17 00:00:00 2001
From: Pavel Tatashin <pasha.tatashin@soleen.com>
Date: Wed, 3 Jun 2020 15:59:27 -0700
Subject: [PATCH] mm: call cond_resched() from deferred_init_memmap()

Now that deferred pages are initialized with interrupts enabled we can
replace touch_nmi_watchdog() with cond_resched(), as it was before
3a2d7fa8a3d5.

For now, we cannot do the same in deferred_grow_zone() as it is still
initializes pages with interrupts disabled.

This change fixes RCU problem described in
https://lkml.kernel.org/r/20200401104156.11564-2-david@redhat.com

[   60.474005] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[   60.475000] rcu:  1-...0: (0 ticks this GP) idle=02a/1/0x4000000000000000 softirq=1/1 fqs=15000
[   60.475000] rcu:  (detected by 0, t=60002 jiffies, g=-1199, q=1)
[   60.475000] Sending NMI from CPU 0 to CPUs 1:
[    1.760091] NMI backtrace for cpu 1
[    1.760091] CPU: 1 PID: 20 Comm: pgdatinit0 Not tainted 4.18.0-147.9.1.el8_1.x86_64 #1
[    1.760091] Hardware name: Red Hat KVM, BIOS 1.13.0-1.module+el8.2.0+5520+4e5817f3 04/01/2014
[    1.760091] RIP: 0010:__init_single_page.isra.65+0x10/0x4f
[    1.760091] Code: 48 83 cf 63 48 89 f8 0f 1f 40 00 48 89 c6 48 89 d7 e8 6b 18 80 ff 66 90 5b c3 31 c0 b9 10 00 00 00 49 89 f8 48 c1 e6 33 f3 ab <b8> 07 00 00 00 48 c1 e2 36 41 c7 40 34 01 00 00 00 48 c1 e0 33 41
[    1.760091] RSP: 0000:ffffba783123be40 EFLAGS: 00000006
[    1.760091] RAX: 0000000000000000 RBX: fffffad34405e300 RCX: 0000000000000000
[    1.760091] RDX: 0000000000000000 RSI: 0010000000000000 RDI: fffffad34405e340
[    1.760091] RBP: 0000000033f3177e R08: fffffad34405e300 R09: 0000000000000002
[    1.760091] R10: 000000000000002b R11: ffff98afb691a500 R12: 0000000000000002
[    1.760091] R13: 0000000000000000 R14: 000000003f03ea00 R15: 000000003e10178c
[    1.760091] FS:  0000000000000000(0000) GS:ffff9c9ebeb00000(0000) knlGS:0000000000000000
[    1.760091] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.760091] CR2: 00000000ffffffff CR3: 000000a1cf20a001 CR4: 00000000003606e0
[    1.760091] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    1.760091] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    1.760091] Call Trace:
[    1.760091]  deferred_init_pages+0x8f/0xbf
[    1.760091]  deferred_init_memmap+0x184/0x29d
[    1.760091]  ? deferred_free_pages.isra.97+0xba/0xba
[    1.760091]  kthread+0x112/0x130
[    1.760091]  ? kthread_flush_work_fn+0x10/0x10
[    1.760091]  ret_from_fork+0x35/0x40
[   89.123011] node 0 initialised, 1055935372 pages in 88650ms

Fixes: 3a2d7fa8a3d5 ("mm: disable interrupts while initializing deferred pages")
Reported-by: Yiqian Wei <yiwei@redhat.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>	[4.17+]
Link: http://lkml.kernel.org/r/20200403140952.17177-4-pasha.tatashin@soleen.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c75561a3f144..2dbc571f68de 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1870,7 +1870,7 @@ static int __init deferred_init_memmap(void *data)
 	 */
 	while (spfn < epfn) {
 		nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn);
-		touch_nmi_watchdog();
+		cond_resched();
 	}
 zone_empty:
 	/* Sanity check that the next zone really is unpopulated */

Re: FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

[Greg KH]

On Thu, Jun 18, 2020 at 05:55:43PM +0200, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 5.7-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

Oops, I applied things out of order, I've queued this and the 5.4
version up, but 4.19 doesn't apply as the dependant patch does not
apply.

thanks

greg k-h

Re: FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

[Sasha Levin]

On Thu, Jun 18, 2020 at 06:26:49PM +0200, Greg KH wrote:
>On Thu, Jun 18, 2020 at 05:55:43PM +0200, gregkh@linuxfoundation.org wrote:
>>
>> The patch below does not apply to the 5.7-stable tree.
>> If someone wants it applied there, or to any other stable or longterm
>> tree, then please email the backport, including the original git commit
>> id to <stable@vger.kernel.org>.
>
>Oops, I applied things out of order, I've queued this and the 5.4
>version up, but 4.19 doesn't apply as the dependant patch does not
>apply.

Something like this should work?

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7181dfe76440..b7905a075e79 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1611,11 +1611,13 @@ static int __init deferred_init_memmap(void *data)
		spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
		epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
		nr_pages += deferred_init_pages(nid, zid, spfn, epfn);
+		cond_resched();
	}
	for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
		spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
		epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
		deferred_free_pages(nid, zid, spfn, epfn);
+		cond_resched();
	}

	/* Sanity check that the next zone really is unpopulated */

-- 
Thanks,
Sasha

Re: FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

[Michal Hocko]

On Thu 18-06-20 22:28:22, Sasha Levin wrote:
> On Thu, Jun 18, 2020 at 06:26:49PM +0200, Greg KH wrote:
> > On Thu, Jun 18, 2020 at 05:55:43PM +0200, gregkh@linuxfoundation.org wrote:
> > > 
> > > The patch below does not apply to the 5.7-stable tree.
> > > If someone wants it applied there, or to any other stable or longterm
> > > tree, then please email the backport, including the original git commit
> > > id to <stable@vger.kernel.org>.
> > 
> > Oops, I applied things out of order, I've queued this and the 5.4
> > version up, but 4.19 doesn't apply as the dependant patch does not
> > apply.
> 
> Something like this should work?

Nope. Unless I am misreading the old code you are udner
pgdat_resize_lock. Or is there any other change queued before this
backport to remove the lock? (I didn't get to check more closely but it
would be 3d060856adfc5 IIRC).

> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 7181dfe76440..b7905a075e79 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1611,11 +1611,13 @@ static int __init deferred_init_memmap(void *data)
> 		spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
> 		epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
> 		nr_pages += deferred_init_pages(nid, zid, spfn, epfn);
> +		cond_resched();
> 	}
> 	for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
> 		spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
> 		epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
> 		deferred_free_pages(nid, zid, spfn, epfn);
> +		cond_resched();
> 	}
> 
> 	/* Sanity check that the next zone really is unpopulated */
> 
> -- 
> Thanks,
> Sasha

-- 
Michal Hocko
SUSE Labs

Re: FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

[David Hildenbrand]

On 19.06.20 11:21, Michal Hocko wrote:
> On Thu 18-06-20 22:28:22, Sasha Levin wrote:
>> On Thu, Jun 18, 2020 at 06:26:49PM +0200, Greg KH wrote:
>>> On Thu, Jun 18, 2020 at 05:55:43PM +0200, gregkh@linuxfoundation.org wrote:
>>>>
>>>> The patch below does not apply to the 5.7-stable tree.
>>>> If someone wants it applied there, or to any other stable or longterm
>>>> tree, then please email the backport, including the original git commit
>>>> id to <stable@vger.kernel.org>.
>>>
>>> Oops, I applied things out of order, I've queued this and the 5.4
>>> version up, but 4.19 doesn't apply as the dependant patch does not
>>> apply.
>>
>> Something like this should work?
> 
> Nope. Unless I am misreading the old code you are udner
> pgdat_resize_lock. Or is there any other change queued before this
> backport to remove the lock? (I didn't get to check more closely but it
> would be 3d060856adfc5 IIRC).

I recently did a similar backport. For pre-5.2, the following commits
might be required to backport cleanly

56ec43d8b027 mm: drop meminit_pfn_in_nid as it is redundant
837566e7e08e mm: implement new zone specific memblock iterator
0e56acae4b4d mm: initialize MAX_ORDER_NR_PAGES at a time instead of
doing larger sections
b9705d8778e7 mm/page_alloc.c: fix regression with deferred struct page init
117003c32771 mm/pagealloc.c: call touch_nmi_watchdog() on max order
boundaries in deferred init
3d060856adfc mm: initialize deferred pages with interrupts enabled
da97f2d56bbd mm: call cond_resched() from deferred_init_memmap()

did not verify, though, if anything else is missing (and which commits
can be bypassed with less trouble).

-- 
Thanks,

David / dhildenb

Re: FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

[Pavel Tatashin]

I will send the backport. I think only three patches are needed that
were in my original series:

117003c32771 mm/pagealloc.c: call touch_nmi_watchdog() on max order
boundaries in deferred init
3d060856adfc mm: initialize deferred pages with interrupts enabled
da97f2d56bbd mm: call cond_resched() from deferred_init_memmap()

Pasha

On Fri, Jun 19, 2020 at 5:44 AM David Hildenbrand <david@redhat.com> wrote:
>
> On 19.06.20 11:21, Michal Hocko wrote:
> > On Thu 18-06-20 22:28:22, Sasha Levin wrote:
> >> On Thu, Jun 18, 2020 at 06:26:49PM +0200, Greg KH wrote:
> >>> On Thu, Jun 18, 2020 at 05:55:43PM +0200, gregkh@linuxfoundation.org wrote:
> >>>>
> >>>> The patch below does not apply to the 5.7-stable tree.
> >>>> If someone wants it applied there, or to any other stable or longterm
> >>>> tree, then please email the backport, including the original git commit
> >>>> id to <stable@vger.kernel.org>.
> >>>
> >>> Oops, I applied things out of order, I've queued this and the 5.4
> >>> version up, but 4.19 doesn't apply as the dependant patch does not
> >>> apply.
> >>
> >> Something like this should work?
> >
> > Nope. Unless I am misreading the old code you are udner
> > pgdat_resize_lock. Or is there any other change queued before this
> > backport to remove the lock? (I didn't get to check more closely but it
> > would be 3d060856adfc5 IIRC).
>
> I recently did a similar backport. For pre-5.2, the following commits
> might be required to backport cleanly
>
> 56ec43d8b027 mm: drop meminit_pfn_in_nid as it is redundant
> 837566e7e08e mm: implement new zone specific memblock iterator
> 0e56acae4b4d mm: initialize MAX_ORDER_NR_PAGES at a time instead of
> doing larger sections
> b9705d8778e7 mm/page_alloc.c: fix regression with deferred struct page init
> 117003c32771 mm/pagealloc.c: call touch_nmi_watchdog() on max order
> boundaries in deferred init
> 3d060856adfc mm: initialize deferred pages with interrupts enabled
> da97f2d56bbd mm: call cond_resched() from deferred_init_memmap()
>
> did not verify, though, if anything else is missing (and which commits
> can be bypassed with less trouble).
>
> --
> Thanks,
>
> David / dhildenb
>

Re: FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

[David Hildenbrand]

On 19.06.20 14:15, Pavel Tatashin wrote:
> I will send the backport. I think only three patches are needed that
> were in my original series:
> 
> 117003c32771 mm/pagealloc.c: call touch_nmi_watchdog() on max order
> boundaries in deferred init
> 3d060856adfc mm: initialize deferred pages with interrupts enabled
> da97f2d56bbd mm: call cond_resched() from deferred_init_memmap()
> 

Just to note, in contrast to the subject, this is about the 4.19
backport IIRC. Is it really only these patches?


-- 
Thanks,

David / dhildenb

Re: FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

[Pavel Tatashin]

> > 117003c32771 mm/pagealloc.c: call touch_nmi_watchdog() on max order
> > boundaries in deferred init
> > 3d060856adfc mm: initialize deferred pages with interrupts enabled
> > da97f2d56bbd mm: call cond_resched() from deferred_init_memmap()
> >
>
> Just to note, in contrast to the subject, this is about the 4.19
> backport IIRC. Is it really only these patches?

Ah, I did not realize it was 4.19 backport.

Yeah, it might be more, I have not checked it.

Thanks,
Pasha

Re: FAILED: patch "[PATCH] mm: call cond_resched() from deferred_init_memmap()" failed to apply to 5.7-stable tree

[Pavel Tatashin]

On Fri, Jun 19, 2020 at 8:43 AM Pavel Tatashin
<pasha.tatashin@soleen.com> wrote:
>
> > > 117003c32771 mm/pagealloc.c: call touch_nmi_watchdog() on max order
> > > boundaries in deferred init
> > > 3d060856adfc mm: initialize deferred pages with interrupts enabled
> > > da97f2d56bbd mm: call cond_resched() from deferred_init_memmap()
> > >
> >
> > Just to note, in contrast to the subject, this is about the 4.19
> > backport IIRC. Is it really only these patches?
>
> Ah, I did not realize it was 4.19 backport.
>
> Yeah, it might be more, I have not checked it.

5.7 backport:
https://lore.kernel.org/stable/20200619122555.372957-1-pasha.tatashin@soleen.com
4.19 backport:
https://lore.kernel.org/stable/20200619132425.425063-1-pasha.tatashin@soleen.com

>
> Thanks,
> Pasha