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Date:   Tue, 1 Mar 2022 17:02:14 -0800
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Subject: Re: [RFC 10/10] trace: platform/x86/intel/ifs: Add trace point to
 track Intel IFS operations
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To:     Steven Rostedt <rostedt@goodmis.org>
CC:     <hdegoede@redhat.com>, <markgross@kernel.org>,
        <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>,
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References: <20220301195457.21152-1-jithu.joseph@intel.com>
 <20220301195457.21152-11-jithu.joseph@intel.com>
 <20220301151744.1ad5e11a@gandalf.local.home>
From:   "Joseph, Jithu" <jithu.joseph@intel.com>
In-Reply-To: <20220301151744.1ad5e11a@gandalf.local.home>
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On 3/1/2022 12:17 PM, Steven Rostedt wrote:
> On Tue,  1 Mar 2022 11:54:57 -0800
> Jithu Joseph <jithu.joseph@intel.com> 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.

Will reorder the fields as you suggested. Appreciate the detailed comment.

Jithu