Re: [patch] perf.data documentation clarify HEADER_SAMPLE_TOPOLOGY format

From: Jiri Olsa <jolsa@redhat.com>
To: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Chong Jiang <chongjiang@chromium.org>,
	Simon Que <sque@chromium.org>
Subject: Re: [patch] perf.data documentation clarify HEADER_SAMPLE_TOPOLOGY format
Date: Fri, 2 Aug 2019 15:14:40 +0200	[thread overview]
Message-ID: <20190802131440.GC27223@krava> (raw)
In-Reply-To: <alpine.DEB.2.21.1908011425240.14303@macbook-air>

On Thu, Aug 01, 2019 at 02:30:43PM -0400, Vince Weaver wrote:
> 
> The perf.data file format documentation for HEADER_SAMPLE_TOPOLOGY 
> specifies the layout in a confusing manner that doesn't match the rest of 
> the document.  This patch attempts to describe things consistent with the 
> rest of the file.
> 
> Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
> 
> diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt
> index 5f54feb19977..6a7dceaae709 100644
> --- a/tools/perf/Documentation/perf.data-file-format.txt
> +++ b/tools/perf/Documentation/perf.data-file-format.txt
> @@ -298,16 +298,21 @@ Physical memory map and its node assignments.
>  
>  The format of data in MEM_TOPOLOGY is as follows:
>  
> -   0 - version          | for future changes
> -   8 - block_size_bytes | /sys/devices/system/memory/block_size_bytes
> -  16 - count            | number of nodes
> -
> -For each node we store map of physical indexes:
> -
> -  32 - node id          | node index
> -  40 - size             | size of bitmap
> -  48 - bitmap           | bitmap of memory indexes that belongs to node
> -                        | /sys/devices/system/node/node<NODE>/memory<INDEX>
> +	u64 version;            // Currently 1
> +	u64 block_size_bytes;   // /sys/devices/system/memory/block_size_bytes
> +	u64 count;              // number of nodes
> +
> +struct memory_node {
> +        u64 node_id;            // node index
> +        u64 size;               // size of bitmap
> +        struct bitmap {
> +		/* size of bitmap again */
> +                u64 bitmapsize; 
> +		/* bitmap of memory indexes that belongs to node     */
> +		/* /sys/devices/system/node/node<NODE>/memory<INDEX> */
> +                u64 entries[(bitmapsize/64)+1];
> +        }
> +}[count];

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks for doing this,
jirka

>  
>  The MEM_TOPOLOGY can be displayed with following command:
>