[ISSUE] `cxl disable-region region0` twice but got same output

[ISSUE] `cxl disable-region region0` twice but got same output

[Cao, Quanquan/曹 全全]

Dear Linux Community Members,

I am writing to seek assistance with a issue that I have encountered 
while testing [Repeat executing the "cxl disable-region region0" 
command]. I have provided a detailed description of the problem along 
with relevant test for reference. I would greatly appreciate it if you 
could spare some time to help me resolve this issue.

Problem Description:

After investigation, it was found that when disabling the region and 
attempting to disable the same region again, the message "cxl region: 
cmd_disable_region: disabled 1 region" is still returned.
I consider this to be unreasonable.


Test Example:

[root@fedora-37-client memory]# cxl list
[
   {
     "memdevs":[
       {
         "memdev":"mem0",
         "ram_size":1073741824,
         "serial":0,
         "host":"0000:0d:00.0"
       }
     ]
   },
   {
     "regions":[
       {
         "region":"region0",
         "resource":27111981056,
         "size":1073741824,
         "type":"ram",
         "interleave_ways":1,
         "interleave_granularity":256,
         "decode_state":"commit"
       }
     ]
   }
]

[root@fedora-37-client ~]# cxl disable-region region0
cxl region: cmd_disable_region: disabled 1 region
[root@fedora-37-client ~]# cxl disable-region region0
cxl region: cmd_disable_region: disabled 1 region

expectation:cmd_disable_region: disabled 0 region


Thank you very much for taking the time to review my issue. I am 
grateful for your assistance and look forward to your response.

Best regards,
Quanquan Cao
caoqq@fujitsu.com

Re: [ISSUE] `cxl disable-region region0` twice but got same output

[Dave Jiang]

On 10/29/23 23:41, Cao, Quanquan/曹 全全 wrote:
> Dear Linux Community Members,
> 
> I am writing to seek assistance with a issue that I have encountered while testing [Repeat executing the "cxl disable-region region0" command]. I have provided a detailed description of the problem along with relevant test for reference. I would greatly appreciate it if you could spare some time to help me resolve this issue.

Hi Quanquan,
I've reproduced the issue. I'll take a look.

> 
> Problem Description:
> 
> After investigation, it was found that when disabling the region and attempting to disable the same region again, the message "cxl region: cmd_disable_region: disabled 1 region" is still returned.
> I consider this to be unreasonable.
> 
> 
> Test Example:
> 
> [root@fedora-37-client memory]# cxl list
> [
>   {
>     "memdevs":[
>       {
>         "memdev":"mem0",
>         "ram_size":1073741824,
>         "serial":0,
>         "host":"0000:0d:00.0"
>       }
>     ]
>   },
>   {
>     "regions":[
>       {
>         "region":"region0",
>         "resource":27111981056,
>         "size":1073741824,
>         "type":"ram",
>         "interleave_ways":1,
>         "interleave_granularity":256,
>         "decode_state":"commit"
>       }
>     ]
>   }
> ]
> 
> [root@fedora-37-client ~]# cxl disable-region region0
> cxl region: cmd_disable_region: disabled 1 region
> [root@fedora-37-client ~]# cxl disable-region region0
> cxl region: cmd_disable_region: disabled 1 region
> 
> expectation:cmd_disable_region: disabled 0 region
> 
> 
> Thank you very much for taking the time to review my issue. I am grateful for your assistance and look forward to your response.
> 
> Best regards,
> Quanquan Cao
> caoqq@fujitsu.com

Re: [ISSUE] `cxl disable-region region0` twice but got same output

[Verma, Vishal L]

On Mon, 2023-10-30 at 14:41 +0800, Cao, Quanquan/曹 全全 wrote:
> 
[..]
> After investigation, it was found that when disabling the region and 
> attempting to disable the same region again, the message "cxl region:
> cmd_disable_region: disabled 1 region" is still returned.
> I consider this to be unreasonable.
> 
> 
> Test Example:
> 
> [root@fedora-37-client memory]# cxl list
> [
>    {
>      "memdevs":[
>        {
>          "memdev":"mem0",
>          "ram_size":1073741824,
>          "serial":0,
>          "host":"0000:0d:00.0"
>        }
>      ]
>    },
>    {
>      "regions":[
>        {
>          "region":"region0",
>          "resource":27111981056,
>          "size":1073741824,
>          "type":"ram",
>          "interleave_ways":1,
>          "interleave_granularity":256,
>          "decode_state":"commit"
>        }
>      ]
>    }
> ]
> 
> [root@fedora-37-client ~]# cxl disable-region region0
> cxl region: cmd_disable_region: disabled 1 region
> [root@fedora-37-client ~]# cxl disable-region region0
> cxl region: cmd_disable_region: disabled 1 region
> 
> expectation:cmd_disable_region: disabled 0 region

This is by design, I think it would be more confusing if the user asks
to disable-region, the response is "disabled 0 regions", and then finds
that the region is actually in the disabled state.

There is also precedent for this, as all disable-<foo> commands in
ndctl and cxl-cli behave the same way.

Perhaps a clarification in the man page makes sense noting this
behavior?

Re: [ISSUE] `cxl disable-region region0` twice but got same output

[Cao, Quanquan/曹 全全]

在 2023/11/1 1:22, Verma, Vishal L 写道:
> On Mon, 2023-10-30 at 14:41 +0800, Cao, Quanquan/曹 全全 wrote:
>>
> [..]
>> After investigation, it was found that when disabling the region and
>> attempting to disable the same region again, the message "cxl region:
>> cmd_disable_region: disabled 1 region" is still returned.
>> I consider this to be unreasonable.
>>
>>
>> Test Example:
>>
>> [root@fedora-37-client memory]# cxl list
>> [
>>     {
>>       "memdevs":[
>>         {
>>           "memdev":"mem0",
>>           "ram_size":1073741824,
>>           "serial":0,
>>           "host":"0000:0d:00.0"
>>         }
>>       ]
>>     },
>>     {
>>       "regions":[
>>         {
>>           "region":"region0",
>>           "resource":27111981056,
>>           "size":1073741824,
>>           "type":"ram",
>>           "interleave_ways":1,
>>           "interleave_granularity":256,
>>           "decode_state":"commit"
>>         }
>>       ]
>>     }
>> ]
>>
>> [root@fedora-37-client ~]# cxl disable-region region0
>> cxl region: cmd_disable_region: disabled 1 region
>> [root@fedora-37-client ~]# cxl disable-region region0
>> cxl region: cmd_disable_region: disabled 1 region
>>
>> expectation:cmd_disable_region: disabled 0 region
> 
> This is by design, I think it would be more confusing if the user asks
> to disable-region, the response is "disabled 0 regions", and then finds
> that the region is actually in the disabled state.
How about adding a hint like ‘region0 already disabled’ before 'disabled 
0 regions'?  I think this could be more friendly for user.

> 
> There is also precedent for this, as all disable-<foo> commands in
> ndctl and cxl-cli behave the same way.
> 
> Perhaps a clarification in the man page makes sense noting this
> behavior?
> 

Re: [ISSUE] `cxl disable-region region0` twice but got same output

[Cao, Quanquan/曹 全全]

在 2023/11/1 1:22, Verma, Vishal L 写道:
> On Mon, 2023-10-30 at 14:41 +0800, Cao, Quanquan/曹 全全 wrote:
>>
> [..]
>> After investigation, it was found that when disabling the region and
>> attempting to disable the same region again, the message "cxl region:
>> cmd_disable_region: disabled 1 region" is still returned.
>> I consider this to be unreasonable.
>>
>>
>> Test Example:
>>
>> [root@fedora-37-client memory]# cxl list
>> [
>>     {
>>       "memdevs":[
>>         {
>>           "memdev":"mem0",
>>           "ram_size":1073741824,
>>           "serial":0,
>>           "host":"0000:0d:00.0"
>>         }
>>       ]
>>     },
>>     {
>>       "regions":[
>>         {
>>           "region":"region0",
>>           "resource":27111981056,
>>           "size":1073741824,
>>           "type":"ram",
>>           "interleave_ways":1,
>>           "interleave_granularity":256,
>>           "decode_state":"commit"
>>         }
>>       ]
>>     }
>> ]
>>
>> [root@fedora-37-client ~]# cxl disable-region region0
>> cxl region: cmd_disable_region: disabled 1 region
>> [root@fedora-37-client ~]# cxl disable-region region0
>> cxl region: cmd_disable_region: disabled 1 region
>>
>> expectation:cmd_disable_region: disabled 0 region
> 
> This is by design, I think it would be more confusing if the user asks
> to disable-region, the response is "disabled 0 regions", and then finds
> that the region is actually in the disabled state.
> 
> There is also precedent for this, as all disable-<foo> commands in
> ndctl and cxl-cli behave the same way.
> 
> Perhaps a clarification in the man page makes sense noting this
> behavior?
> 
About this,i would like to ask if the design adopts the "idempotency" 
pattern