LKML News v5.17-rc3

[PATCH] selftests: kselftest framework: Provide “finished” helper (Kees Cook)

https://lkml.kernel.org/r/20220201013717.2464392-1-keescook@chromium.org

Users who want to use ksft_exit() need to figure out the internals of kselftest. This commit adds a helper function for that purpose, namely, ksft_finished().

[LSF/MM/BPF TOPIC] Handling of VMAs (Liam Howlett)

https://lkml.kernel.org/r/20220201150521.owa5axfsmpdvc7uo@revolver

Liam is pointing out the VMAs are quite complicately managed with their cache, tree, linked list, and even reverse mapping. As it now shows its limit with the lock contention and complexity of the handling code, he wants to propose a simpler new way for their management.

[LSF/MM/BPF TOPIC] The Maple Tree (Liam Howlett)

https://lkml.kernel.org/r/20220201150633.jtlwrqfnh4xbhw2f@revolver

Maple tree is a RCU-safe range-based B-tree, which is designed to be used for better VMAs management. He proposes to discuss about how it could be used for many complicated scenarios.

[LSF/MM/BPF TOPIC] mm documentation (Mike Rapoport)

https://lkml.kernel.org/r/YfmD9Pa92xousy5b@kernel.org

Mike Rapoport proposes to discuss how we can improve the mm documentation, which is not so up to date for now.

[LSF/MM/BPF TOPIC] Consolidating representations of the physical memory (Mike Rapoport)

https://lkml.kernel.org/r/YfmEtd3vg/x7uqXx@kernel.org

Currently, the physical memory is represented using multiple structures including memblock, iomem_resource, ‘System Ram’, per-architecture structures. As this makes code inconsistent and complex, Mike is proposing to use single abstraction having [start, end, flags], namely memblock. He is proposing to discuss about this further in LSF/MM/BPF.

[LSF/MM/BPF TOPIC] Amortising direct map fragmentation (Mike Rapoport)

https://lkml.kernel.org/r/YfmFMvNu9oNGryjv@kernel.org

Direct map fragmentation, which causes split of the PUD and PMD-sized mappings in the direct map can lead to performance degradation. Mike proposes to discuss about how we can improve the situation in LSM/MM/BPF.

mmotm 2022-02-01-16-04 uploaded (Andrew Morton)

https://lkml.kernel.org/r/20220202000522.A3834C340EB@smtp.kernel.org

Andrew updated the mmotm. It’s rebased on 5.17-rc2, added 78 new patches, modified 25 existing patches, and dropped 16 patches. In total, 226 patches in the queue.

[PATCH] mm/damon: Add option to monitor only writes (Pedro Demarchi Gomes)

https://lkml.kernel.org/r/20220203131237.298090-1-pedrodemargomes@gmail.com

Pedro is proposing write-only monitoring for DAMON. It’s using soft-dirty bits on virtual address space monitoring primitive.

mmotm 2022-02-03-21-58 uploaded (Andrew Morton)

https://lkml.kernel.org/r/20220204055842.0D8D0C004E1@smtp.kernel.org

Andrew updated the mmotm. It’s still based on 5.17-rc2. This time, it added 20 new patches, modified 50 existing patches, and dropped 4 patches. In total, 242 patches in the queue.

Linux 5.17-rc3 (Linus Torvalds)

https://lkml.kernel.org/r/CAHk-=wiKr3q0ABWL0me+ugjN87zBOFXnBi43=-rBu7+WDKwQVA@mail.gmail.com

The third candidate for v5.17 release has out with normal shape. Filesystem might have unusual diff stat, but it’s not due to single one problematic part. Changes for drivers are still dominating the stat, though.

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 2020-02-07 | ~/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 -rc3 releases in the last two years.