[dm-devel] [PATCH 1/2] multipath.conf(5): remove io-affinity information

[Mike Christie]

On 12/3/22 9:10 AM, Xose Vazquez Perez wrote:
> On 11/30/22 05:56, bmarzins at redhat.com (Benjamin Marzinski) wrote:
> 
>> The multpath-tools do not support the io-affinity path selector.  We
>> always add a repeat count as the path argument. The io-affinity selector
>> doesn't take one. Instead it takes a bitmap of CPUs that a path can run
>> on. This isn't something that lends itself to the kind of
>> auto-assembling that multipathd does. But even if we did want to try to
>> support this path-selector, until we do, we shouldn't be listing it in
>> the multipath.conf documentation.
>>
>> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> 
>> ---
>>   multipath/multipath.conf.5 | 4 ----
>>   1 file changed, 4 deletions(-)
>>
>> diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5
>> index 1fea9d5a..3a45ac89 100644
>> --- a/multipath/multipath.conf.5
>> +++ b/multipath/multipath.conf.5
>> @@ -205,10 +205,6 @@ of outstanding I/O to the path and its relative throughput.
>>   estimation of future service time based on the history of previous I/O submitted
>>   to each path.
>>   .TP
>> -.I "io-affinity 0"
>> -(Since 5.11 kernel) Choose the path for the next bunch of I/O based on a CPU to
>> -path mapping the user passes in and what CPU we are executing on.
>> -.TP
>>   The default is: \fBservice-time 0\fR
>>   .RE
>>   .
> 
> I think the main, and only?, consumer for this path selector is Exadata.

Not exadata but another user in oracle.

The patch is ok with me. We've been setting it up manually. When I get time
to do multipathd support I'll update the docs as well.