LKML News v5.15-rc2

[PATCH v1] vmpressure: wake up work only when there is registration event (wangyong)

https://lkml.kernel.org/r/1631548441-2784-1-git-send-email-wang.yong12@zte.com.cn

Currently, vmpressure works are awaken even though there are no vmpressure callbacks. This commit avoids such unnecessary wakeup by counting the number of registered events and skip waking up works if the number is zero.

[PATCH v3 00/76] Optimize list lru memory consumption (Muchun Song)

https://lkml.kernel.org/r/20210914072938.6440-1-songmuchun@bytedance.com

Muchun found kmalloc-32 for list_lru_one allocation consuming 6 GiB of memory on their server. That came from a large number of containers. This patchset aims to optimize the memory consumption by adding the memcg to the list_lru at the first insert, rather than instantiating all at memcg init time.

For creating 10,000 memcg and mounting 10,000 filesystems, this patchset reduced the memory consumption from 24 GiB to 4 GiB.

[MAINTAINER SUMMIT] Folios as a potential Kernel/Maintainers Summit topic? (Theodore Ts’o)

https://lkml.kernel.org/r/YUIwgGzBqX6ZiGgk@mit.edu

Folio is still not merged in the mainline. Ted says, as a file system developer he is eagerly looking forward to what Folios will enable. For the reason, he suggests to have a maintainer summit topic for Folio. In detail, take a place in a LPC BOF room in Friday.

[PATCH 0/2] Fix NUMA without SMP (Geert Uytterhoeven)

https://lkml.kernel.org/r/cover.1631781495.git.geert+renesas@glider.be

There are variables and functions which are used by the NUMA code for SMP-only case. This causes build errors for SuperH architecture, which supports NUMA without SMP. This patch fixes it.

[PATCH] mm: add ztree - new allocator for use via zpool API (Ananda Badmaev)

https://lkml.kernel.org/r/20210916085102.19310-1-a.badmaev@clicknet.pro

This patch provides a backend for zswap, which uses red-black trees for storing compressed objects blocks. This might be able to be used by zram, either.

mmotm 2021-09-16-14-00 uploaded (Andrew Morton)

https://lkml.kernel.org/r/20210916210058.KrWpsFx8b%akpm@linux-foundation.org

Andrew updated the first mmotm after v5.15 merge window had opened. Compared to the last mmotm before the merge window, 351 patches dropped, 74 patches added, and 23 patches modified.

Linux 5.15-rc2 (Linus Torvalds)

https://lkml.kernel.org/r/CAHk-=wirexiZR+VO=H3xemGKOMkh8OasmXaKXTKUmAKYCzi8AQ@mail.gmail.com/

Due to the Werror change, Linus spent lots of time for the build warning fixes. Thouh the change has been not default, Linus apparently wants to eliminate all the warnings. The work is not complete yet, but he really hopes the kernel to built without warning.

Below is the diffstat of the releases in the last two years.

Note that the y-axis is in logarithm. I draw it using https://github.com/sjp38/relstat and https://github.com/sjp38/lazybox using below command:

$ relstat.py --since 2019-09-20 | ~/lazybox/gnuplot/plot.py \
    --data_fmt table --type labeled-lines --xtics_rotate -90 \
    --font "Times New Roman, 5pt" --ylog --pointsize 0.3

And, below is the diffstat of the -rc2 releases in the last two years.