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* Issue with stack) on 6.x kernels
@ 2024-05-01  1:48 Kris Van Hees
  2024-05-01 13:58 ` Kris Van Hees
  0 siblings, 1 reply; 3+ messages in thread
From: Kris Van Hees @ 2024-05-01  1:48 UTC (permalink / raw
  To: dtrace, DTrace development list

Newer 6.x kernels (I tried 6.5.0 and 6.8.0) seem to behave differently for
stack() than e.g. 5,15,0,  Test test/unittest/aggs/tst.stack.d FAILs on those
6.x kernels whereas it passes on 5.15.0.  I am not sure yet why there is a
difference, but Eugene, perhaps you can take a look into this?

	Kris

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Issue with stack) on 6.x kernels
  2024-05-01  1:48 Issue with stack) on 6.x kernels Kris Van Hees
@ 2024-05-01 13:58 ` Kris Van Hees
  2024-05-01 17:15   ` [DTrace-devel] " Alan Maguire
  0 siblings, 1 reply; 3+ messages in thread
From: Kris Van Hees @ 2024-05-01 13:58 UTC (permalink / raw
  To: Kris Van Hees; +Cc: dtrace, DTrace development list

On Tue, Apr 30, 2024 at 09:48:02PM -0400, Kris Van Hees wrote:
> Newer 6.x kernels (I tried 6.5.0 and 6.8.0) seem to behave differently for
> stack() than e.g. 5,15,0,  Test test/unittest/aggs/tst.stack.d FAILs on those
> 6.x kernels whereas it passes on 5.15.0.  I am not sure yet why there is a
> difference, but Eugene, perhaps you can take a look into this?
> 
> 	Kris

Here is an example:

$ sudo ./build/run-dtrace -s test/unittest/aggs/tst.stack.d 
[sudo] password for kvanhees: 
  0xffffffffc0129e86                                
  0xffffffffc0129e86                                
  0xffffffffc0129e86                                

              0xffffffffc0130250
              0xffffffffc0130250
              0xffffffffc012b2bb
              0xffffffffc012b83c
              vmlinux`schedule+0x9

The strange thing is that it actually does give good results at times.

So I am not sure what is going on.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [DTrace-devel] Issue with stack) on 6.x kernels
  2024-05-01 13:58 ` Kris Van Hees
@ 2024-05-01 17:15   ` Alan Maguire
  0 siblings, 0 replies; 3+ messages in thread
From: Alan Maguire @ 2024-05-01 17:15 UTC (permalink / raw
  To: Kris Van Hees; +Cc: dtrace, DTrace development list

On 01/05/2024 14:58, Kris Van Hees via DTrace-devel wrote:
> On Tue, Apr 30, 2024 at 09:48:02PM -0400, Kris Van Hees wrote:
>> Newer 6.x kernels (I tried 6.5.0 and 6.8.0) seem to behave differently for
>> stack() than e.g. 5,15,0,  Test test/unittest/aggs/tst.stack.d FAILs on those
>> 6.x kernels whereas it passes on 5.15.0.  I am not sure yet why there is a
>> difference, but Eugene, perhaps you can take a look into this?
>>
>> 	Kris
> 
> Here is an example:
> 
> $ sudo ./build/run-dtrace -s test/unittest/aggs/tst.stack.d 
> [sudo] password for kvanhees: 
>   0xffffffffc0129e86                                
>   0xffffffffc0129e86                                
>   0xffffffffc0129e86                                
> 
>               0xffffffffc0130250
>               0xffffffffc0130250
>               0xffffffffc012b2bb
>               0xffffffffc012b83c
>               vmlinux`schedule+0x9
> 
> The strange thing is that it actually does give good results at times.
> 
> So I am not sure what is going on.
>

here's an upstream thread discussing stacks + fentry:

https://lore.kernel.org/bpf/49b9b6f.1279.18aadb90e05.Coremail.chang-liu22@mails.tsinghua.edu.cn/

Looks like the top few entries relate to the trampoline and fentry program..

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> DTrace-devel mailing list
> DTrace-devel@oss.oracle.com
> https://oss.oracle.com/mailman/listinfo/dtrace-devel

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2024-05-01 17:15 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2024-05-01  1:48 Issue with stack) on 6.x kernels Kris Van Hees
2024-05-01 13:58 ` Kris Van Hees
2024-05-01 17:15   ` [DTrace-devel] " Alan Maguire

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