Re: [PATCH] eventdev: fix alignment padding

["Mattias Rönnblom" <mattias.ronnblom@ericsson.com>]

On 2023-04-18 13:06, Morten Brørup wrote:
>> From: Sivaprasad Tummala [mailto:sivaprasad.tummala@amd.com]
>> Sent: Tuesday, 18 April 2023 12.46
>>
>> fixed the padding required to align to cacheline size.
>>
>> Fixes: 54f17843a887 ("eventdev: add port maintenance API")
>> Cc: mattias.ronnblom@ericsson.com
>>
>> Signed-off-by: Sivaprasad Tummala <sivaprasad.tummala@amd.com>
>> ---
>>   lib/eventdev/rte_eventdev_core.h | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/lib/eventdev/rte_eventdev_core.h
>> b/lib/eventdev/rte_eventdev_core.h
>> index c328bdbc82..c27a52ccc0 100644
>> --- a/lib/eventdev/rte_eventdev_core.h
>> +++ b/lib/eventdev/rte_eventdev_core.h
>> @@ -65,7 +65,7 @@ struct rte_event_fp_ops {
>>   	/**< PMD Tx adapter enqueue same destination function. */
>>   	event_crypto_adapter_enqueue_t ca_enqueue;
>>   	/**< PMD Crypto adapter enqueue function. */
>> -	uintptr_t reserved[6];
>> +	uintptr_t reserved[5];
>>   } __rte_cache_aligned;
> 
> This fix changes the size (reduces it by one cache line) of the elements in the public rte_event_fp_ops array, and thus breaks the ABI.
> 
> BTW, the patch it fixes, which was dated November 2021, also broke the ABI.

21.11 has a new ABI version, so that's not an issue.

> 
>>
>>   extern struct rte_event_fp_ops rte_event_fp_ops[RTE_EVENT_MAX_DEVS];
>> --
>> 2.34.1