LKML News v6.2

[PATCH] mm/userfaultfd: Support operation on multiple VMAs (Muhammad Usama Anjum)

https://lkml.kernel.org/r/20230213104323.1792839-1-usama.anjum@collabora.com

mwriteprotect_range() handle only single VMA, but there are usecases which need to handle multiple VMAs in a memory range of interest. This commit fixes the case.

[v2 PATCH 0/5] Introduce mempool pages bulk allocator and use it in dm-crypt (Yang Shi)

https://lkml.kernel.org/r/20230214190221.1156876-1-shy828301@gmail.com

Noticeable overhead on disc encryption due to page allocations have found. The overhead was because the allocation logic in dm-crypt allocates one page in each pass of a loop. This patchset introduces a new bulk allocator API and use it for dm-crypt.

[PATCH v3 00/35] Per-VMA locks (Suren Baghdasaryan)

https://lkml.kernel.org/r/20230216051750.3125598-1-surenb@google.com

Third version of the patchset for improving vma locking overhead has posted.

[LSF/MM/BPF TOPIC] Using hardware counters to determine hot/cold pages

https://lkml.kernel.org/r/6bbf2c47-05ab-b78c-3165-2eff18962d6d@linux.ibm.com

PowerPC provides access counter and access affinity details at configurable page size granularity. Aneesh propose to introduce it and discuss about the best ways to integrate it in the Linux kernel.

[LSF/MM/BPF TOPIC] Scalable Pagefaults (Matthew Wilcox)

https://lkml.kernel.org/r/Y+/f9slIaK195fRX@casper.infradead.org

Matthew is proposing yet another topic for continueing the page faults multi CPU scalability issue. He hopes the per-VMA locks patchset to be merged in at least mm tree by the time, and be able to discuss further improvements.

Linux 6.2 (Linus Torvalds)

https://lkml.kernel.org/r/CAHk-=wio46vC4t6xXD-sFqjoPwFm_u515jm3suzmkGxQTeA1_A@mail.gmail.com

Linux v6.2 has released as expected, with the extended schedule. There were some more fixes for some regressions, but Linus didn’t merge those because the maintainers didn’t push. Those would be merged in stable release of 6.2, later.

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 2021-02-20 | ~/lazybox/gnuplot/plot.py \
    --data_fmt table --type labeled-lines --xtics_rotate -90 \
    --font "Times New Roman, 5pt" --ylog --pointsize 0.3