Re: [PATCH v5 2/2] perf record: Update docs regarding the maximum limitation of AUX area

[Shuai Xue]

On 2023/9/7 08:43, Shuai Xue wrote:
> The maximum AUX area is limited by the page size of the system. Update
> the documentation to reflect this.
> 
> Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
> ---
>  tools/perf/Documentation/perf-record.txt | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index 680396c56bd1..dfc322d6f1f1 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -292,6 +292,17 @@ OPTIONS
>  	Also, by adding a comma, the number of mmap pages for AUX
>  	area tracing can be specified.
>  
> +	The maximum AUX area is limited by the maximum physically contiguous
> +	memory allocated from slab/slub. It can be calculated with following
> +	formula:
> +
> +	  PAGE_SIZE << MAX_ORDER
> +	( ---------------------- ) * PAGE_SIZE
> +	   sizeof(page_pointer)
> +
> +	For example with 4K pages and MAX_ORDER=10 configured, the maximum AUX
> +	area is 2GiB.
> +
>  -g::
>  	Enables call-graph (stack chain/backtrace) recording for both
>  	kernel space and user space.


Hi, Namhyung,

Since PATCH [1/2] of this series has been merge into perf/core[1], are you happy to
pick this part [2/2] into perf-tools-next?

Thank you.

Best Regards,
Shuai

[1] https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=perf/core&id=54aee5f15b83437f23b2b2469bcf21bdd9823916