Re: [RFC 10/10] trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations

From: Steven Rostedt
Date: Tue Mar 01 2022 - 15:19:04 EST


On Tue, 1 Mar 2022 11:54:57 -0800
Jithu Joseph <jithu.joseph@xxxxxxxxx> wrote:

> + TP_STRUCT__entry(
> + __field( u8, start )
> + __field( u8, stop )
> + __field( u64, status )
> + ),

I'd suggest swapping this to:

__field( u64, status )
__field( u8, start )
__field( u8, stop )

As trace events are usually aligned by 4 bytes (sometimes 8 for archs that
require 8byte alignment for 8 byte words), but any event, putting the
padding at the end of the event is better than in the middle of the event.

Having the u64 come after two u8 (two byes) will pretty much guarantee a 6
bytes hole in the middle of the event.

-- Steve