* Re: [RFC]mm/zsmalloc,: trigger BUG_ON in function zs_map_object.
@ 2017-03-29 0:20 ` Minchan Kim
0 siblings, 0 replies; 10+ messages in thread
From: Minchan Kim @ 2017-03-29 0:20 UTC (permalink / raw)
To: Yisheng Xie
Cc: ngupta, sergey.senozhatsky.work, linux-mm,
Linux Kernel Mailing List, Xishi Qiu, Hanjun Guo
Hello,
On Tue, Mar 28, 2017 at 03:20:22PM +0800, Yisheng Xie wrote:
> Hi, all,
>
> We had backport the no-lru migration to linux-4.1, meanwhile change the
> ZS_MAX_ZSPAGE_ORDER to 3. Then we met a BUG_ON(!page[1]).
Hmm, I don't know how you backported.
There isn't any problem with default ZS_MAX_ZSPAGE_ORDER. Right?
So, it happens only if you changed it to 3?
Could you tell me what is your base kernel? and what zram/zsmalloc
version(ie, from what kernel version) you backported to your
base kernel?
>
> It rarely happen, and presently, what I get is:
> [6823.316528s]obj=a160701f, obj_idx=15, class{size:2176,objs_per_zspage:15,pages_per_zspage:8}
> [...]
> [6823.316619s]BUG: failure at /home/ethan/kernel/linux-4.1/mm/zsmalloc.c:1458/zs_map_object()! ----> BUG_ON(!page[1])
>
> It seems that we have allocated an object from a ZS_FULL group?
> (Actually， I do not get the inuse number of this zspage, which I am trying to.)
> And presently, I can not find why it happened. Any idea about it?
Although it happens rarely, always above same symptom once it happens?
>
> Any comment is more than welcome!
>
> Thanks
> Yisheng Xie
>
>
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [RFC]mm/zsmalloc,: trigger BUG_ON in function zs_map_object.
2017-03-29 0:20 ` Minchan Kim
@ 2017-03-29 6:42 ` Sergey Senozhatsky
-1 siblings, 0 replies; 10+ messages in thread
From: Sergey Senozhatsky @ 2017-03-29 6:42 UTC (permalink / raw)
To: Minchan Kim, Yisheng Xie
Cc: ngupta, sergey.senozhatsky.work, linux-mm,
Linux Kernel Mailing List, Xishi Qiu, Hanjun Guo
On (03/29/17 09:20), Minchan Kim wrote:
> Hello,
>
> On Tue, Mar 28, 2017 at 03:20:22PM +0800, Yisheng Xie wrote:
> > Hi, all,
> >
> > We had backport the no-lru migration to linux-4.1, meanwhile change the
> > ZS_MAX_ZSPAGE_ORDER to 3. Then we met a BUG_ON(!page[1]).
>
> Hmm, I don't know how you backported.
>
> There isn't any problem with default ZS_MAX_ZSPAGE_ORDER. Right?
> So, it happens only if you changed it to 3?
I agree with Minchan. too much things could have gone wrong during the backport.
> Could you tell me what is your base kernel? and what zram/zsmalloc
> version(ie, from what kernel version) you backported to your
> base kernel?
agree again.
Yisheng, do you have this commit applied?
commit c102f07ca0b04f2cb49cfc161c83f6239d17f491
Author: Junil Lee <junil0814.lee@lge.com>
Date: Wed Jan 20 14:58:18 2016 -0800
zsmalloc: fix migrate_zspage-zs_free race condition
-ss
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [RFC]mm/zsmalloc,: trigger BUG_ON in function zs_map_object.
@ 2017-03-29 6:42 ` Sergey Senozhatsky
0 siblings, 0 replies; 10+ messages in thread
From: Sergey Senozhatsky @ 2017-03-29 6:42 UTC (permalink / raw)
To: Minchan Kim, Yisheng Xie
Cc: ngupta, sergey.senozhatsky.work, linux-mm,
Linux Kernel Mailing List, Xishi Qiu, Hanjun Guo
On (03/29/17 09:20), Minchan Kim wrote:
> Hello,
>
> On Tue, Mar 28, 2017 at 03:20:22PM +0800, Yisheng Xie wrote:
> > Hi, all,
> >
> > We had backport the no-lru migration to linux-4.1, meanwhile change the
> > ZS_MAX_ZSPAGE_ORDER to 3. Then we met a BUG_ON(!page[1]).
>
> Hmm, I don't know how you backported.
>
> There isn't any problem with default ZS_MAX_ZSPAGE_ORDER. Right?
> So, it happens only if you changed it to 3?
I agree with Minchan. too much things could have gone wrong during the backport.
> Could you tell me what is your base kernel? and what zram/zsmalloc
> version(ie, from what kernel version) you backported to your
> base kernel?
agree again.
Yisheng, do you have this commit applied?
commit c102f07ca0b04f2cb49cfc161c83f6239d17f491
Author: Junil Lee <junil0814.lee@lge.com>
Date: Wed Jan 20 14:58:18 2016 -0800
zsmalloc: fix migrate_zspage-zs_free race condition
-ss
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^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [RFC]mm/zsmalloc,: trigger BUG_ON in function zs_map_object.
2017-03-29 6:42 ` Sergey Senozhatsky
@ 2017-03-29 7:53 ` Yisheng Xie
-1 siblings, 0 replies; 10+ messages in thread
From: Yisheng Xie @ 2017-03-29 7:53 UTC (permalink / raw)
To: Sergey Senozhatsky, Minchan Kim
Cc: ngupta, sergey.senozhatsky.work, linux-mm,
Linux Kernel Mailing List, Xishi Qiu, Hanjun Guo
Hi Sergey,
Thanks for your comment!
On 2017/3/29 14:42, Sergey Senozhatsky wrote:
> On (03/29/17 09:20), Minchan Kim wrote:
>> Hello,
>>
>> On Tue, Mar 28, 2017 at 03:20:22PM +0800, Yisheng Xie wrote:
>>> Hi, all,
>>>
>>> We had backport the no-lru migration to linux-4.1, meanwhile change the
>>> ZS_MAX_ZSPAGE_ORDER to 3. Then we met a BUG_ON(!page[1]).
>>
>> Hmm, I don't know how you backported.
>>
>> There isn't any problem with default ZS_MAX_ZSPAGE_ORDER. Right?
>> So, it happens only if you changed it to 3?
>
> I agree with Minchan. too much things could have gone wrong during the backport.
>
>> Could you tell me what is your base kernel? and what zram/zsmalloc
>> version(ie, from what kernel version) you backported to your
>> base kernel?
>
> agree again.
>
>
>
> Yisheng, do you have this commit applied?
No, we missed this patch, I will try it. Really thanks for that.
Thanks
Yisheng Xie
>
> commit c102f07ca0b04f2cb49cfc161c83f6239d17f491
> Author: Junil Lee <junil0814.lee@lge.com>
> Date: Wed Jan 20 14:58:18 2016 -0800
>
> zsmalloc: fix migrate_zspage-zs_free race condition
>
>
> -ss
>
> .
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [RFC]mm/zsmalloc,: trigger BUG_ON in function zs_map_object.
@ 2017-03-29 7:53 ` Yisheng Xie
0 siblings, 0 replies; 10+ messages in thread
From: Yisheng Xie @ 2017-03-29 7:53 UTC (permalink / raw)
To: Sergey Senozhatsky, Minchan Kim
Cc: ngupta, sergey.senozhatsky.work, linux-mm,
Linux Kernel Mailing List, Xishi Qiu, Hanjun Guo
Hi Sergey,
Thanks for your comment!
On 2017/3/29 14:42, Sergey Senozhatsky wrote:
> On (03/29/17 09:20), Minchan Kim wrote:
>> Hello,
>>
>> On Tue, Mar 28, 2017 at 03:20:22PM +0800, Yisheng Xie wrote:
>>> Hi, all,
>>>
>>> We had backport the no-lru migration to linux-4.1, meanwhile change the
>>> ZS_MAX_ZSPAGE_ORDER to 3. Then we met a BUG_ON(!page[1]).
>>
>> Hmm, I don't know how you backported.
>>
>> There isn't any problem with default ZS_MAX_ZSPAGE_ORDER. Right?
>> So, it happens only if you changed it to 3?
>
> I agree with Minchan. too much things could have gone wrong during the backport.
>
>> Could you tell me what is your base kernel? and what zram/zsmalloc
>> version(ie, from what kernel version) you backported to your
>> base kernel?
>
> agree again.
>
>
>
> Yisheng, do you have this commit applied?
No, we missed this patch, I will try it. Really thanks for that.
Thanks
Yisheng Xie
>
> commit c102f07ca0b04f2cb49cfc161c83f6239d17f491
> Author: Junil Lee <junil0814.lee@lge.com>
> Date: Wed Jan 20 14:58:18 2016 -0800
>
> zsmalloc: fix migrate_zspage-zs_free race condition
>
>
> -ss
>
> .
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [RFC]mm/zsmalloc,: trigger BUG_ON in function zs_map_object.
2017-03-29 0:20 ` Minchan Kim
@ 2017-03-29 7:51 ` Yisheng Xie
-1 siblings, 0 replies; 10+ messages in thread
From: Yisheng Xie @ 2017-03-29 7:51 UTC (permalink / raw)
To: Minchan Kim
Cc: ngupta, sergey.senozhatsky.work, linux-mm,
Linux Kernel Mailing List, Xishi Qiu, Hanjun Guo
Hi Minchan,
Thanks for your comment!
On 2017/3/29 8:20, Minchan Kim wrote:
> Hello,
>
> On Tue, Mar 28, 2017 at 03:20:22PM +0800, Yisheng Xie wrote:
>> Hi, all,
>>
>> We had backport the no-lru migration to linux-4.1, meanwhile change the
>> ZS_MAX_ZSPAGE_ORDER to 3. Then we met a BUG_ON(!page[1]).
>
> Hmm, I don't know how you backported.
Yes, maybe caused by our unsuitable backport.
>
> There isn't any problem with default ZS_MAX_ZSPAGE_ORDER. Right?
> So, it happens only if you changed it to 3?
I will check whether it will default ZS_MAX_ZSPAGE_ORDER.
>
> Could you tell me what is your base kernel? and what zram/zsmalloc
> version(ie, from what kernel version) you backported to your
> base kernel?
>
We backport from kernel v4.8-rc8 to kernel v4.1.
>>
>> It rarely happen, and presently, what I get is:
>> [6823.316528s]obj=a160701f, obj_idx=15, class{size:2176,objs_per_zspage:15,pages_per_zspage:8}
>> [...]
>> [6823.316619s]BUG: failure at /home/ethan/kernel/linux-4.1/mm/zsmalloc.c:1458/zs_map_object()! ----> BUG_ON(!page[1])
>>
>> It seems that we have allocated an object from a ZS_FULL group?
>> (Actually， I do not get the inuse number of this zspage, which I am trying to.)
>> And presently, I can not find why it happened. Any idea about it?
>
> Although it happens rarely, always above same symptom once it happens?
Yes , though the class size is not the same, which means not from the same class.
however, the (obj_idx == objs_per_zspage) is always true.
Thanks
Yisheng Xie.
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [RFC]mm/zsmalloc,: trigger BUG_ON in function zs_map_object.
@ 2017-03-29 7:51 ` Yisheng Xie
0 siblings, 0 replies; 10+ messages in thread
From: Yisheng Xie @ 2017-03-29 7:51 UTC (permalink / raw)
To: Minchan Kim
Cc: ngupta, sergey.senozhatsky.work, linux-mm,
Linux Kernel Mailing List, Xishi Qiu, Hanjun Guo
Hi Minchan,
Thanks for your comment!
On 2017/3/29 8:20, Minchan Kim wrote:
> Hello,
>
> On Tue, Mar 28, 2017 at 03:20:22PM +0800, Yisheng Xie wrote:
>> Hi, all,
>>
>> We had backport the no-lru migration to linux-4.1, meanwhile change the
>> ZS_MAX_ZSPAGE_ORDER to 3. Then we met a BUG_ON(!page[1]).
>
> Hmm, I don't know how you backported.
Yes, maybe caused by our unsuitable backport.
>
> There isn't any problem with default ZS_MAX_ZSPAGE_ORDER. Right?
> So, it happens only if you changed it to 3?
I will check whether it will default ZS_MAX_ZSPAGE_ORDER.
>
> Could you tell me what is your base kernel? and what zram/zsmalloc
> version(ie, from what kernel version) you backported to your
> base kernel?
>
We backport from kernel v4.8-rc8 to kernel v4.1.
>>
>> It rarely happen, and presently, what I get is:
>> [6823.316528s]obj=a160701f, obj_idx=15, class{size:2176,objs_per_zspage:15,pages_per_zspage:8}
>> [...]
>> [6823.316619s]BUG: failure at /home/ethan/kernel/linux-4.1/mm/zsmalloc.c:1458/zs_map_object()! ----> BUG_ON(!page[1])
>>
>> It seems that we have allocated an object from a ZS_FULL group?
>> (Actuallyi 1/4 ? I do not get the inuse number of this zspage, which I am trying to.)
>> And presently, I can not find why it happened. Any idea about it?
>
> Although it happens rarely, always above same symptom once it happens?
Yes , though the class size is not the same, which means not from the same class.
however, the (obj_idx == objs_per_zspage) is always true.
Thanks
Yisheng Xie.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 10+ messages in thread