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* [PATCH] mm: fix trying to reclaim unevicable LRU page
@ 2019-05-24  7:11 Minchan Kim
  2019-05-24  7:21 ` Minchan Kim
  2019-05-28 15:14 ` Michal Hocko
  0 siblings, 2 replies; 9+ messages in thread
From: Minchan Kim @ 2019-05-24  7:11 UTC (permalink / raw)
  To: Andrew Morton
  Cc: Michal Hocko, linux-mm, LKML, Minchan Kim, stable, Wu Fangsuo

There was below bugreport from Wu Fangsuo.

7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
..
7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0

Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
routine so that it couldn't reach the VM_BUG_ON_PAGE line.

To fix the issue, this patch filter out unevictable LRU pages
from the reclaim_clean_pages_from_list in CMA.

[1] ad6b67041a45, mm: remove SWAP_MLOCK in ttu

Cc: <stable@kernel.org>	[4.12+]
Reported-debugged-by: Wu Fangsuo <fangsuowu@asrmicro.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index d9c3e873eca6..7350afae5c3c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1505,7 +1505,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
 
 	list_for_each_entry_safe(page, next, page_list, lru) {
 		if (page_is_file_cache(page) && !PageDirty(page) &&
-		    !__PageMovable(page)) {
+		    !__PageMovable(page) && !PageUnevictable(page)) {
 			ClearPageActive(page);
 			list_move(&page->lru, &clean_pages);
 		}
-- 
2.22.0.rc1.257.g3120a18244-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] mm: fix trying to reclaim unevicable LRU page
  2019-05-24  7:11 [PATCH] mm: fix trying to reclaim unevicable LRU page Minchan Kim
@ 2019-05-24  7:21 ` Minchan Kim
  2019-05-28 15:14 ` Michal Hocko
  1 sibling, 0 replies; 9+ messages in thread
From: Minchan Kim @ 2019-05-24  7:21 UTC (permalink / raw)
  To: Andrew Morton; +Cc: Michal Hocko, linux-mm, LKML, stable, Wu Fangsuo

On Fri, May 24, 2019 at 04:11:14PM +0900, Minchan Kim wrote:
> There was below bugreport from Wu Fangsuo.
> 
> 7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
> 7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
> 7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
> 7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
> 7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
> 7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
> 7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
> 7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
> 7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> 7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
> 7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
> 7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
> 7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
> 7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
> 7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
> 7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
> 7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
> ..
> 7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
> 7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
> 7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
> 7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
> 7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
> 7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
> 7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
> 7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
> 7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0
> 
> Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
> routine so that it couldn't reach the VM_BUG_ON_PAGE line.
> 
> To fix the issue, this patch filter out unevictable LRU pages
> from the reclaim_clean_pages_from_list in CMA.
> 
> [1] ad6b67041a45, mm: remove SWAP_MLOCK in ttu
> 
> Cc: <stable@kernel.org>	[4.12+]
> Reported-debugged-by: Wu Fangsuo <fangsuowu@asrmicro.com>
Tested-by: Wu Fangsuo <fangsuowu@asrmicro.com>

I forgot to add his Tested-by. Sorry about that.

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] mm: fix trying to reclaim unevicable LRU page
  2019-05-24  7:11 [PATCH] mm: fix trying to reclaim unevicable LRU page Minchan Kim
  2019-05-24  7:21 ` Minchan Kim
@ 2019-05-28 15:14 ` Michal Hocko
  2019-05-30  2:42   ` Minchan Kim
  1 sibling, 1 reply; 9+ messages in thread
From: Michal Hocko @ 2019-05-28 15:14 UTC (permalink / raw)
  To: Minchan Kim
  Cc: Andrew Morton, linux-mm, LKML, stable, Wu Fangsuo, Pankaj Suryawanshi

[Cc Pankaj Suryawanshi who has reported a similar problem
http://lkml.kernel.org/r/SG2PR02MB309806967AE91179CAFEC34BE84B0@SG2PR02MB3098.apcprd02.prod.outlook.com]

On Fri 24-05-19 16:11:14, Minchan Kim wrote:
> There was below bugreport from Wu Fangsuo.
> 
> 7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
> 7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
> 7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
> 7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
> 7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
> 7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
> 7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
> 7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
> 7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> 7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
> 7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
> 7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
> 7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
> 7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
> 7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
> 7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
> 7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
> ..
> 7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
> 7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
> 7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
> 7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
> 7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
> 7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
> 7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
> 7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
> 7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0
> 
> Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
> routine so that it couldn't reach the VM_BUG_ON_PAGE line.
> 
> To fix the issue, this patch filter out unevictable LRU pages
> from the reclaim_clean_pages_from_list in CMA.

The changelog is rather modest on details and I have to confess I have
little bit hard time to understand it. E.g. why do not we need to handle
the regular reclaim path?

> [1] ad6b67041a45, mm: remove SWAP_MLOCK in ttu
> 
> Cc: <stable@kernel.org>	[4.12+]
> Reported-debugged-by: Wu Fangsuo <fangsuowu@asrmicro.com>
> Signed-off-by: Minchan Kim <minchan@kernel.org>
> ---
>  mm/vmscan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index d9c3e873eca6..7350afae5c3c 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1505,7 +1505,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
>  
>  	list_for_each_entry_safe(page, next, page_list, lru) {
>  		if (page_is_file_cache(page) && !PageDirty(page) &&
> -		    !__PageMovable(page)) {
> +		    !__PageMovable(page) && !PageUnevictable(page)) {
>  			ClearPageActive(page);
>  			list_move(&page->lru, &clean_pages);
>  		}
> -- 
> 2.22.0.rc1.257.g3120a18244-goog
> 

-- 
Michal Hocko
SUSE Labs

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] mm: fix trying to reclaim unevicable LRU page
  2019-05-28 15:14 ` Michal Hocko
@ 2019-05-30  2:42   ` Minchan Kim
  2019-06-04 12:28     ` Michal Hocko
  0 siblings, 1 reply; 9+ messages in thread
From: Minchan Kim @ 2019-05-30  2:42 UTC (permalink / raw)
  To: Michal Hocko
  Cc: Andrew Morton, linux-mm, LKML, stable, Wu Fangsuo, Pankaj Suryawanshi

On Tue, May 28, 2019 at 05:14:07PM +0200, Michal Hocko wrote:
> [Cc Pankaj Suryawanshi who has reported a similar problem
> http://lkml.kernel.org/r/SG2PR02MB309806967AE91179CAFEC34BE84B0@SG2PR02MB3098.apcprd02.prod.outlook.com]
> 
> On Fri 24-05-19 16:11:14, Minchan Kim wrote:
> > There was below bugreport from Wu Fangsuo.
> > 
> > 7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
> > 7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
> > 7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
> > 7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
> > 7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
> > 7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
> > 7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
> > 7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
> > 7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> > 7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
> > 7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
> > 7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
> > 7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
> > 7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
> > 7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
> > 7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
> > 7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
> > ..
> > 7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
> > 7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
> > 7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
> > 7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
> > 7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
> > 7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
> > 7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
> > 7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
> > 7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0
> > 
> > Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
> > routine so that it couldn't reach the VM_BUG_ON_PAGE line.
> > 
> > To fix the issue, this patch filter out unevictable LRU pages
> > from the reclaim_clean_pages_from_list in CMA.
> 
> The changelog is rather modest on details and I have to confess I have
> little bit hard time to understand it. E.g. why do not we need to handle
> the regular reclaim path?

No need to pass unevictable pages into regular reclaim patch if we are
able to know in advance.

> 
> > [1] ad6b67041a45, mm: remove SWAP_MLOCK in ttu
> > 
> > Cc: <stable@kernel.org>	[4.12+]
> > Reported-debugged-by: Wu Fangsuo <fangsuowu@asrmicro.com>
> > Signed-off-by: Minchan Kim <minchan@kernel.org>
> > ---
> >  mm/vmscan.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/mm/vmscan.c b/mm/vmscan.c
> > index d9c3e873eca6..7350afae5c3c 100644
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -1505,7 +1505,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
> >  
> >  	list_for_each_entry_safe(page, next, page_list, lru) {
> >  		if (page_is_file_cache(page) && !PageDirty(page) &&
> > -		    !__PageMovable(page)) {
> > +		    !__PageMovable(page) && !PageUnevictable(page)) {
> >  			ClearPageActive(page);
> >  			list_move(&page->lru, &clean_pages);
> >  		}
> > -- 
> > 2.22.0.rc1.257.g3120a18244-goog
> > 
> 
> -- 
> Michal Hocko
> SUSE Labs

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] mm: fix trying to reclaim unevicable LRU page
  2019-05-30  2:42   ` Minchan Kim
@ 2019-06-04 12:28     ` Michal Hocko
  2019-06-10  9:42       ` Minchan Kim
  0 siblings, 1 reply; 9+ messages in thread
From: Michal Hocko @ 2019-06-04 12:28 UTC (permalink / raw)
  To: Minchan Kim
  Cc: Andrew Morton, linux-mm, LKML, stable, Wu Fangsuo, Pankaj Suryawanshi

On Thu 30-05-19 11:42:29, Minchan Kim wrote:
> On Tue, May 28, 2019 at 05:14:07PM +0200, Michal Hocko wrote:
> > [Cc Pankaj Suryawanshi who has reported a similar problem
> > http://lkml.kernel.org/r/SG2PR02MB309806967AE91179CAFEC34BE84B0@SG2PR02MB3098.apcprd02.prod.outlook.com]
> > 
> > On Fri 24-05-19 16:11:14, Minchan Kim wrote:
> > > There was below bugreport from Wu Fangsuo.
> > > 
> > > 7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
> > > 7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
> > > 7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
> > > 7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
> > > 7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
> > > 7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
> > > 7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
> > > 7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
> > > 7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> > > 7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
> > > 7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
> > > 7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
> > > 7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
> > > 7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
> > > 7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
> > > 7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
> > > 7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
> > > ..
> > > 7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
> > > 7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
> > > 7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
> > > 7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
> > > 7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
> > > 7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
> > > 7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
> > > 7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
> > > 7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0
> > > 
> > > Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
> > > routine so that it couldn't reach the VM_BUG_ON_PAGE line.
> > > 
> > > To fix the issue, this patch filter out unevictable LRU pages
> > > from the reclaim_clean_pages_from_list in CMA.
> > 
> > The changelog is rather modest on details and I have to confess I have
> > little bit hard time to understand it. E.g. why do not we need to handle
> > the regular reclaim path?
> 
> No need to pass unevictable pages into regular reclaim patch if we are
> able to know in advance.

I am sorry to be dense here. So what is the difference in the CMA path?
Am I right that the pfn walk (CMA) rather than LRU isolation (reclaim)
is the key differentiator?

-- 
Michal Hocko
SUSE Labs

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] mm: fix trying to reclaim unevicable LRU page
  2019-06-04 12:28     ` Michal Hocko
@ 2019-06-10  9:42       ` Minchan Kim
  2019-06-10 10:39         ` Michal Hocko
  0 siblings, 1 reply; 9+ messages in thread
From: Minchan Kim @ 2019-06-10  9:42 UTC (permalink / raw)
  To: Michal Hocko
  Cc: Andrew Morton, linux-mm, LKML, stable, Wu Fangsuo, Pankaj Suryawanshi

On Tue, Jun 04, 2019 at 02:28:06PM +0200, Michal Hocko wrote:
> On Thu 30-05-19 11:42:29, Minchan Kim wrote:
> > On Tue, May 28, 2019 at 05:14:07PM +0200, Michal Hocko wrote:
> > > [Cc Pankaj Suryawanshi who has reported a similar problem
> > > http://lkml.kernel.org/r/SG2PR02MB309806967AE91179CAFEC34BE84B0@SG2PR02MB3098.apcprd02.prod.outlook.com]
> > > 
> > > On Fri 24-05-19 16:11:14, Minchan Kim wrote:
> > > > There was below bugreport from Wu Fangsuo.
> > > > 
> > > > 7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
> > > > 7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
> > > > 7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
> > > > 7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
> > > > 7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
> > > > 7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
> > > > 7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
> > > > 7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
> > > > 7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> > > > 7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
> > > > 7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
> > > > 7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
> > > > 7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
> > > > 7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
> > > > 7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
> > > > 7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
> > > > 7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
> > > > ..
> > > > 7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
> > > > 7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
> > > > 7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
> > > > 7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
> > > > 7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
> > > > 7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
> > > > 7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
> > > > 7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
> > > > 7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0
> > > > 
> > > > Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
> > > > routine so that it couldn't reach the VM_BUG_ON_PAGE line.
> > > > 
> > > > To fix the issue, this patch filter out unevictable LRU pages
> > > > from the reclaim_clean_pages_from_list in CMA.
> > > 
> > > The changelog is rather modest on details and I have to confess I have
> > > little bit hard time to understand it. E.g. why do not we need to handle
> > > the regular reclaim path?
> > 
> > No need to pass unevictable pages into regular reclaim patch if we are
> > able to know in advance.
> 
> I am sorry to be dense here. So what is the difference in the CMA path?
> Am I right that the pfn walk (CMA) rather than LRU isolation (reclaim)
> is the key differentiator?

Yes.
We could isolate unevictable LRU pages from the pfn waker to migrate and
could discard clean file-backed pages to reduce migration latency in CMA
path.


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] mm: fix trying to reclaim unevicable LRU page
  2019-06-10  9:42       ` Minchan Kim
@ 2019-06-10 10:39         ` Michal Hocko
  2019-06-10 11:21           ` Minchan Kim
  0 siblings, 1 reply; 9+ messages in thread
From: Michal Hocko @ 2019-06-10 10:39 UTC (permalink / raw)
  To: Minchan Kim
  Cc: Andrew Morton, linux-mm, LKML, stable, Wu Fangsuo, Pankaj Suryawanshi

On Mon 10-06-19 18:42:22, Minchan Kim wrote:
> On Tue, Jun 04, 2019 at 02:28:06PM +0200, Michal Hocko wrote:
> > On Thu 30-05-19 11:42:29, Minchan Kim wrote:
> > > On Tue, May 28, 2019 at 05:14:07PM +0200, Michal Hocko wrote:
> > > > [Cc Pankaj Suryawanshi who has reported a similar problem
> > > > http://lkml.kernel.org/r/SG2PR02MB309806967AE91179CAFEC34BE84B0@SG2PR02MB3098.apcprd02.prod.outlook.com]
> > > > 
> > > > On Fri 24-05-19 16:11:14, Minchan Kim wrote:
> > > > > There was below bugreport from Wu Fangsuo.
> > > > > 
> > > > > 7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
> > > > > 7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
> > > > > 7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
> > > > > 7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
> > > > > 7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
> > > > > 7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
> > > > > 7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
> > > > > 7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
> > > > > 7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> > > > > 7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
> > > > > 7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
> > > > > 7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
> > > > > 7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
> > > > > 7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
> > > > > 7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
> > > > > 7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
> > > > > 7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
> > > > > ..
> > > > > 7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
> > > > > 7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
> > > > > 7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
> > > > > 7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
> > > > > 7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
> > > > > 7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
> > > > > 7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
> > > > > 7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
> > > > > 7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0
> > > > > 
> > > > > Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
> > > > > routine so that it couldn't reach the VM_BUG_ON_PAGE line.
> > > > > 
> > > > > To fix the issue, this patch filter out unevictable LRU pages
> > > > > from the reclaim_clean_pages_from_list in CMA.
> > > > 
> > > > The changelog is rather modest on details and I have to confess I have
> > > > little bit hard time to understand it. E.g. why do not we need to handle
> > > > the regular reclaim path?
> > > 
> > > No need to pass unevictable pages into regular reclaim patch if we are
> > > able to know in advance.
> > 
> > I am sorry to be dense here. So what is the difference in the CMA path?
> > Am I right that the pfn walk (CMA) rather than LRU isolation (reclaim)
> > is the key differentiator?
> 
> Yes.
> We could isolate unevictable LRU pages from the pfn waker to migrate and
> could discard clean file-backed pages to reduce migration latency in CMA
> path.

Please be explicit about that in the changelog. The fact that this is
not possible from the regular reclaim path is really important and not
obvious from the first glance.

Thanks!

-- 
Michal Hocko
SUSE Labs

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] mm: fix trying to reclaim unevicable LRU page
  2019-06-10 10:39         ` Michal Hocko
@ 2019-06-10 11:21           ` Minchan Kim
  2019-06-10 21:13             ` Michal Hocko
  0 siblings, 1 reply; 9+ messages in thread
From: Minchan Kim @ 2019-06-10 11:21 UTC (permalink / raw)
  To: Michal Hocko
  Cc: Andrew Morton, linux-mm, LKML, stable, Wu Fangsuo, Pankaj Suryawanshi

On Mon, Jun 10, 2019 at 12:39:46PM +0200, Michal Hocko wrote:
> On Mon 10-06-19 18:42:22, Minchan Kim wrote:
> > On Tue, Jun 04, 2019 at 02:28:06PM +0200, Michal Hocko wrote:
> > > On Thu 30-05-19 11:42:29, Minchan Kim wrote:
> > > > On Tue, May 28, 2019 at 05:14:07PM +0200, Michal Hocko wrote:
> > > > > [Cc Pankaj Suryawanshi who has reported a similar problem
> > > > > http://lkml.kernel.org/r/SG2PR02MB309806967AE91179CAFEC34BE84B0@SG2PR02MB3098.apcprd02.prod.outlook.com]
> > > > > 
> > > > > On Fri 24-05-19 16:11:14, Minchan Kim wrote:
> > > > > > There was below bugreport from Wu Fangsuo.
> > > > > > 
> > > > > > 7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
> > > > > > 7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
> > > > > > 7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
> > > > > > 7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
> > > > > > 7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
> > > > > > 7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
> > > > > > 7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
> > > > > > 7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
> > > > > > 7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> > > > > > 7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
> > > > > > 7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
> > > > > > 7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
> > > > > > 7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
> > > > > > 7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
> > > > > > 7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
> > > > > > 7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
> > > > > > 7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
> > > > > > ..
> > > > > > 7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
> > > > > > 7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
> > > > > > 7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
> > > > > > 7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
> > > > > > 7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
> > > > > > 7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
> > > > > > 7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
> > > > > > 7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
> > > > > > 7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0
> > > > > > 
> > > > > > Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
> > > > > > routine so that it couldn't reach the VM_BUG_ON_PAGE line.
> > > > > > 
> > > > > > To fix the issue, this patch filter out unevictable LRU pages
> > > > > > from the reclaim_clean_pages_from_list in CMA.
> > > > > 
> > > > > The changelog is rather modest on details and I have to confess I have
> > > > > little bit hard time to understand it. E.g. why do not we need to handle
> > > > > the regular reclaim path?
> > > > 
> > > > No need to pass unevictable pages into regular reclaim patch if we are
> > > > able to know in advance.
> > > 
> > > I am sorry to be dense here. So what is the difference in the CMA path?
> > > Am I right that the pfn walk (CMA) rather than LRU isolation (reclaim)
> > > is the key differentiator?
> > 
> > Yes.
> > We could isolate unevictable LRU pages from the pfn waker to migrate and
> > could discard clean file-backed pages to reduce migration latency in CMA
> > path.
> 
> Please be explicit about that in the changelog. The fact that this is
> not possible from the regular reclaim path is really important and not
> obvious from the first glance.
> 
> Thanks!

Here it goes:

Andrew, could you replace the patch with the below if Michal doesn't have
any suggestion?

Thanks.

From 5cb8958ea240e2580bd2b331448009e8e1854240 Mon Sep 17 00:00:00 2001
From: Minchan Kim <minchan@kernel.org>
Date: Fri, 24 May 2019 15:54:10 +0900
Subject: [PATCH] mm: fix trying to reclaim unevicable LRU page

There was below bugreport from Wu Fangsuo.

In CMA allocation path, isolate_migratepages_range could isolate unevictable
LRU pages and reclaim_clean_page_from_list can try to reclaim them if
they are clean file-backed pages.

7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
..
7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0

Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
routine so that it couldn't reach the VM_BUG_ON_PAGE line.

To fix the issue, this patch filter out unevictable LRU pages
from the reclaim_clean_pages_from_list in CMA.

[1] ad6b67041a45, mm: remove SWAP_MLOCK in ttu

Cc: <stable@kernel.org>	[4.12+]
Reported-debugged-by: Wu Fangsuo <fangsuowu@asrmicro.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index d9c3e873eca6..7350afae5c3c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1505,7 +1505,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
 
 	list_for_each_entry_safe(page, next, page_list, lru) {
 		if (page_is_file_cache(page) && !PageDirty(page) &&
-		    !__PageMovable(page)) {
+		    !__PageMovable(page) && !PageUnevictable(page)) {
 			ClearPageActive(page);
 			list_move(&page->lru, &clean_pages);
 		}
-- 
2.22.0.rc2.383.gf4fbbf30c2-goog



^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] mm: fix trying to reclaim unevicable LRU page
  2019-06-10 11:21           ` Minchan Kim
@ 2019-06-10 21:13             ` Michal Hocko
  0 siblings, 0 replies; 9+ messages in thread
From: Michal Hocko @ 2019-06-10 21:13 UTC (permalink / raw)
  To: Minchan Kim
  Cc: Andrew Morton, linux-mm, LKML, stable, Wu Fangsuo, Pankaj Suryawanshi

On Mon 10-06-19 20:21:12, Minchan Kim wrote:
[...]
> >From 5cb8958ea240e2580bd2b331448009e8e1854240 Mon Sep 17 00:00:00 2001
> From: Minchan Kim <minchan@kernel.org>
> Date: Fri, 24 May 2019 15:54:10 +0900
> Subject: [PATCH] mm: fix trying to reclaim unevicable LRU page
> 
> There was below bugreport from Wu Fangsuo.
> 
> In CMA allocation path, isolate_migratepages_range could isolate unevictable
> LRU pages and reclaim_clean_page_from_list can try to reclaim them if
> they are clean file-backed pages.
> 
> 7200 [  680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
> 7201 [  680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
> 7202 [  680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
> 7203 [  680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
> 7204 [  680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
> 7205 [  680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80
> 7206 [  680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------
> 7207 [  680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
> 7223 [  680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> 7224 [  680.611436] c0 7125 (syz-executor) Modules linked in:
> 7225 [  680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
> 7226 [  680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT)
> 7227 [  680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000
> 7228 [  680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240
> 7229 [  680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240
> 7230 [  680.656303] c0 7125 (syz-executor) pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
> 7231 [  680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940
> ..
> 7342 [  681.671308] c0 7125 (syz-executor) [<ffffff90083a2158>] shrink_page_list+0x1998/0x3240
> 7343 [  681.679567] c0 7125 (syz-executor) [<ffffff90083a3dc0>] reclaim_clean_pages_from_list+0x3c0/0x4f0
> 7344 [  681.688793] c0 7125 (syz-executor) [<ffffff900837ed64>] alloc_contig_range+0x3bc/0x650
> 7347 [  681.717421] c0 7125 (syz-executor) [<ffffff90084925cc>] cma_alloc+0x214/0x668
> 7348 [  681.724892] c0 7125 (syz-executor) [<ffffff90091e4d78>] ion_cma_allocate+0x98/0x1d8
> 7349 [  681.732872] c0 7125 (syz-executor) [<ffffff90091e0b20>] ion_alloc+0x200/0x7e0
> 7350 [  681.740302] c0 7125 (syz-executor) [<ffffff90091e154c>] ion_ioctl+0x18c/0x378
> 7351 [  681.747738] c0 7125 (syz-executor) [<ffffff90084c6824>] do_vfs_ioctl+0x17c/0x1780
> 7352 [  681.755514] c0 7125 (syz-executor) [<ffffff90084c7ed4>] SyS_ioctl+0xac/0xc0
> 
> Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked
> routine so that it couldn't reach the VM_BUG_ON_PAGE line.
> 
> To fix the issue, this patch filter out unevictable LRU pages
> from the reclaim_clean_pages_from_list in CMA.
> 
> [1] ad6b67041a45, mm: remove SWAP_MLOCK in ttu
> 
> Cc: <stable@kernel.org>	[4.12+]
> Reported-debugged-by: Wu Fangsuo <fangsuowu@asrmicro.com>
> Signed-off-by: Minchan Kim <minchan@kernel.org>

OK, this looks better. Thanks!
Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  mm/vmscan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index d9c3e873eca6..7350afae5c3c 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1505,7 +1505,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
>  
>  	list_for_each_entry_safe(page, next, page_list, lru) {
>  		if (page_is_file_cache(page) && !PageDirty(page) &&
> -		    !__PageMovable(page)) {
> +		    !__PageMovable(page) && !PageUnevictable(page)) {
>  			ClearPageActive(page);
>  			list_move(&page->lru, &clean_pages);
>  		}
> -- 
> 2.22.0.rc2.383.gf4fbbf30c2-goog
> 

-- 
Michal Hocko
SUSE Labs

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2019-06-10 21:13 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-05-24  7:11 [PATCH] mm: fix trying to reclaim unevicable LRU page Minchan Kim
2019-05-24  7:21 ` Minchan Kim
2019-05-28 15:14 ` Michal Hocko
2019-05-30  2:42   ` Minchan Kim
2019-06-04 12:28     ` Michal Hocko
2019-06-10  9:42       ` Minchan Kim
2019-06-10 10:39         ` Michal Hocko
2019-06-10 11:21           ` Minchan Kim
2019-06-10 21:13             ` Michal Hocko

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