LKML News v5.13

[PATCH v4] mm: introduce reference pages (Peter Collingbourne)

https://lkml.kernel.org/r/20210619092002.1791322-1-pcc@google.com

This patch introduces a new syscall, refpage_create(). This system creates a file descriptor which can be mmap-ed using mmap(), which will be similar to anonymous mapping but the memory will be backed by a reference page instead of the zero page.

[PATCH 0/3] mm/page_reporting: Make page reporting work on arm64 with 64KB page size (Gavin Shan)

https://lkml.kernel.org/r/20210621051152.305224-1-gshan@redhat.com

This patchset makes the page reporting to work on ARM with more realistic threshold, which is 2MB instead of 512MB, when the system’s page size is 64KB. This will be very helpful for memory-fragmented systems.

[LSF/MM TOPIC] Impact on core mm from new hardware features (Dave Hansen)

https://lkml.kernel.org/r/51d3010b-6324-2441-42c0-27bb536c897d@intel.com

Dave is proposing a LSF/MM session for discussion on core mm changes for Intel’s new hardware features including shadow stack, linear address masking, supervisor protection key, and TDX.

[PATCH v12 00/33] Memory folios (Matthew Wilcox)

https://lkml.kernel.org/r/20210622114118.3388190-1-willy@infradead.org

This patchset introduces memory folio, which is a new abstraction for pages of different size. This makes the handling of compound pages be easy.

[PATCH v2 00/46] Folio-enabling the page cache (Matthew Wilcox)

https://lkml.kernel.org/r/20210622121551.3398730-1-willy@infradead.org

This patchset converts filesystems to use memory folios.

[PATCH 1/1] mm: introduce process_reap system call (Suren Baghdasaryan)

https://lkml.kernel.org/r/20210623192822.3072029-1-surenb@google.com

This patch introduces a new system call, process_reap(), which reclaims memory of a dying process from the caller’s context. This can be helpful for reclaiming memory consumed by other process in predictable time.

[PATCH -V9 0/9] Migrate Pages in lieu of discard (Huang Ying)

https://lkml.kernel.org/r/20210625073204.1005986-1-ying.huang@intel.com

A patchset for the tiered memory systems. This patchset makes cold pages to be located in slower memory, like pmem.

Linux 5.13 (Linus Torvalds)

https://lkml.kernel.org/r/CAHk-=wj7E9iTGHbqfgtaTAM09WrVzwXjda2_D59MT8D_1=54Rg@mail.gmail.com

After the seven release candidates, Linux v5.13 is out. It is one of the bigger 5.x releases. It has over 16k commits from over 2k people. Obviously, this also means the merge window for 5.14 has opened.

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 2019-06-28 | ~/lazybox/gnuplot/plot.py \
    --data_fmt table --type labeled-lines --xtics_rotate -90 \
    --font "Times New Roman, 5pt" --ylog --pointsize 0.3