Received-SPF: pass (google.com: domain of linux-kernel+bounces-19610-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Date: Mon, 8 Jan 2024 13:23:25 +0000
From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Ira Weiny <ira.weiny@intel.com>
CC: Dan Williams <dan.j.williams@intel.com>, Smita Koralahalli
	<Smita.KoralahalliChannabasappa@amd.com>, Shiju Jose <shiju.jose@huawei.com>,
	Yazen Ghannam <yazen.ghannam@amd.com>, "Davidlohr Bueso" <dave@stgolabs.net>,
	Dave Jiang <dave.jiang@intel.com>, "Alison Schofield"
	<alison.schofield@intel.com>, Vishal Verma <vishal.l.verma@intel.com>, Ard
 Biesheuvel <ardb@kernel.org>, <linux-efi@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-cxl@vger.kernel.org>
Subject: Re: [PATCH v5 4/9] cxl/events: Remove passing a UUID to known event
 traces
Message-ID: <20240108132325.00000e9c@Huawei.com>
In-Reply-To: <20231220-cxl-cper-v5-4-1bb8a4ca2c7a@intel.com>
References: <20231220-cxl-cper-v5-0-1bb8a4ca2c7a@intel.com>
	<20231220-cxl-cper-v5-4-1bb8a4ca2c7a@intel.com>
Organization: Huawei Technologies Research and Development (UK) Ltd.
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit

On Wed, 20 Dec 2023 16:17:31 -0800
Ira Weiny <ira.weiny@intel.com> wrote:

> The UUID data is redundant in the known event trace types.  The addition
> of static defines allows the trace macros to create the UUID data inside
> the trace thus removing unnecessary code.
> 
> Have well known trace events use static data to set the uuid field based
> on the event type.
> 
> Suggested-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> 

>  	TP_STRUCT__entry(
>  		CXL_EVT_TP_entry
> @@ -422,7 +424,8 @@ TRACE_EVENT(cxl_dram,
>  	),
>  
>  	TP_fast_assign(
> -		CXL_EVT_TP_fast_assign(cxlmd, log, uuid, rec->hdr);
> +		CXL_EVT_TP_fast_assign(cxlmd, log, rec->hdr);
> +		memcpy(&__entry->hdr_uuid, &CXL_EVENT_DRAM_UUID, sizeof(uuid_t));

Hmm. Why not

		__entry->hdr_uuid = CXL_EVENT_DRAM_UUID;
?

Compiler should be able to squish the stuff in the define down to data as as the
UUID generation logic is pretty simple.

I've not emulated the cper records for these yet, so not tested that works beyond
compiling.

J