Yes, CONFIG_PAGE_POOL_STATS (which first appeared in commit 50de1591 a month ago) does incur additional CPU cost, as do many other options that are enabled in the default arch config, such as CONFIG_CRYPTO_STATS, CONFIG_FSCACHE_STATS and friends. Many debugging options are enabled as well. zgrep -E '(_STATS|_DEBUG)=y' /proc/config.gz It seems that the `linux` package was designed to fit most workloads, as it enables an excessive amount of options and modules that are not usually enabled in other distributions. If you do not like this, you can build a kernel with them disabled[1]. Albeit, the performance tax imposed by enabling these stats, debug options should be trivial compared to other factors such as the compiler used, optimisations, LTO, etc[2]. [1] https://gitlab.archlinux.org/archlinux/packaging/packages/linux [2] https://openbenchmarking.org/result/2305211-NE-EPYCGENOA71#results --- Paul M. Ärloch Debes praebere lingvam scriptvm vt hanc paginam inspicias. ------- Original Message ------- On Thursday, August 10th, 2023 at 8:37 AM, sunying@isrc.iscas.ac.cn wrote:

Hello,

I recently noticed that in Arch Linux 2023.08.01, CONFIG_PAGE_POOL_STATS=y.

As we know, this option incurs additional CPU and memory cost. In addition to enabling this option, these statistics are only available if the driver using the page pool supports exporting this data.

Does enabling this configuration by default have any performance impact? Is it necessary to enable it by default?

Thank you for your time.

------------------------------ Institute of Software Chinese Academy of Sciences

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Mail:sunying@isrc.iscas.ac.cn

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