Re: [dpdk-users] compile warning in dpdk lib header files "error: inlining failed in call .... call is unlikely and code size would grow"

[Yuyong Zhang <yuyong.zhang@casa-systems.com>]

Thanks Stephen for the quick response.



For performance considerations, which one is better:



1.     Use –Wno-error=inline to turn off the warning which compiler will not do inline for the warned inline function

or

2.     Modify dpdk header file to add __attribute__((always_inline)) to force complier to always do inline for these functions.



I assume option-2 is better for performance, any suggestions?



Thanks a lot.



Regards,



Yuyong







-----Original Message-----
From: Stephen Hemminger [mailto:stephen@networkplumber.org]
Sent: Friday, September 8, 2017 3:08 PM
To: Yuyong Zhang <yuyong.zhang@casa-systems.com>
Cc: users@dpdk.org
Subject: Re: [dpdk-users] compile warning in dpdk lib header files "error: inlining failed in call .... call is unlikely and code size would grow"



On Fri, 8 Sep 2017 18:45:52 +0000

Yuyong Zhang <yuyong.zhang@casa-systems.com<mailto:yuyong.zhang@casa-systems.com>> wrote:



> Hi,

>

>

>

> I got lots of compile warning when integrating dpdk library such as:

>

>

>

> : error: inlining failed in call to ‘rte_mempool_ops_dequeue_bulk.part.1’: call is unlikely and code size would grow [-Werror=inline]

>

>

>

> : error: inlining failed in call to ‘rte_pktmbuf_free": call is unlikely and code size would grow [-Werror=inline]

>

>

>

> Because company policy strictly enforces "waring as error", I have to fix those issues.



Turn off the warning, or fix the policy.



DPDK does lots of inlining and in some cases the code will be used in unlikely branchs.