LKML News v5.15

Dynamically allocated memory descriptors (Matthew Wilcox)

https://lkml.kernel.org/r/YXcLqcFhDq3uUwIj@casper.infradead.org

In this mail, Matthew explains his idea on making struct page only two words and how it could work with buddy allocator freelists.

[RFC] mm: Disable NUMA_BALANCING_DEFAULT_ENABLED and TRANSPARENT_HUGEPAGE on PREEMPT_RT (Sebastian Andrzej Siewior)

https://lkml.kernel.org/r/20211026165100.ahz5bkx44lrrw5pt@linutronix.de

Mel told RT patchset could incur spikes on NUMA machines when NUMA_BALANCING and THP are turned on. Sebastian request comments on disabling those on RT enabled kernel by default, but still trying to find a good test for that.

mmotm 2021-10-27-18-32 uploaded (Andrew Morton)

https://lkml.kernel.org/r/20211028013301.pr6m56GoH%akpm@linux-foundation.org

The -mm of the moment tree is updated. This update adds 69 patches, modify 68 patches, drops no patch. 435 patches in total in the -mm tree.

[PATCH] mm: Disable NUMA_BALANCING_DEFAULT_ENABLED and TRANSPARENT_HUGEPAGE on PREEMPT_RT (Sebastian Andrzej)

https://lkml.kernel.org/r/20211028143327.hfbxjze7palrpfgp@linutronix.de

After getting some feedback, this patch removed RFC tag.

incoming (Andrew Morton)

https://lkml.kernel.org/r/20211028143506.5f5d5e2cd1f768a1da864844@linux-foundation.org

11 patches for fixes of v5.15 are posted from Andrew to Linus.

[GIT PULL] Memory folios for v5.16 (Matthew Wilcox)

https://lkml.kernel.org/r/YX4RkYNNZtO9WL0L@casper.infradead.org

Matthew is sending the memory folios pull request again, for v5.16. I personally curious what feedback will come for this time.

This pull request merged in the mainline for v5.16.

Linux 5.15 (Linus Torvalds)

https://lkml.kernel.org/r/CAHk-=wjfbfQobW2jygMvgfJXKmzZNB=UTzBrFs2vTEzVpBXA4Q@mail.gmail.com

The 5.15 of Linux has released in the normal 9 weeks cycle, with DAMON. It started with pains due to the -Werror, but the pace has been normal soon. This also means the merge window for 5.16 is open. DAMON following patches for DAMOS and DAMON-based proactive reclamation are in -next tree. Let’s see if those will be merged in this merge window.

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 2019-11-01 | ~/lazybox/gnuplot/plot.py \
    --data_fmt table --type labeled-lines --xtics_rotate -90 \
    --font "Times New Roman, 5pt" --ylog --pointsize 0.3