[PATCH v16 QEMU 4/3 RFC] memory: Add support for MADV_FREE as mechanism to lazy discard pages https://lkml.kernel.org/r/20200103212339.29849.99817.stgit@localhost.localdomain
This RFC patch modifies QEMU to able to use MADV_FREE for discard of pages to avoid the page zeroing cost.
Linux 5.5-rc5 https://lkml/kernel.org/r/CAHk-=whwmJQwwMD06VfPapDmc52LFQhG3HP6VyVLXVA=nYi_ow@mail.gmail.com
Time files, rc5 released. Last week was also another calm week due to the new year holidays, and thus this release is small. Linus expects it will be changed in this upcoming weeks, or 5.
[PATCH V11 RESEND] mm/debug: Add tests validating architecture page table helpers https://lkml.kernel.org/r/1577162322-30303-1-git-send-email-anshuman.khandual@arm.com
This patchset adds tests for the page table helpers. Those tests covers basic page table entry transformations including old, young, dirty, clean, write, write protect etc. The tests are not using the kselftest or kunit, but implemented as a kernel module with new file, mm/debug_vm_pgtable.c.
Linux 5.5-rc4 https://lkml.kernel.org/r/CAHk-=wjq2b9GkLzpaDE-Xryu5c0zMM72BqkJKeZVsX+4ymH6aA@mail.gmail.com
Due to the holidays, last week was unsurprisingly quiet. Torvalds says it was hardly even worth making an rc release.
PROBLEM: Large (256MB) CMA allocation fails from time to time when using Intel VT-d https://lkml.kernel.org/r/5e75d900cb50457784ee1d2050b511ec@MAILER13.tech.ceia
The author reports a CMA allocation failure that occurs time to time if the system is using Intel VT-d.
[PATCHv2 0/3] Allow ZRAM to use any zpool-compatible backend https://lkml.kernel.org/r/20191219151928.ad4ccf732b64b7f8a26116db@gmail.com
ZRAM is an in-memory block device that compresses the content. Currently, ZRAM is used only with zsmalloc. However, the zsmalloc is not an optimal selection in some environment.
[PATCHSET 0/5] Support for RWF_UNCACHED https://lkml.kernel.org/r/20191210162454.8608-1-axboe@kernel.dk
As the buffered IO uses the page cache, an intensive buffered IO workload using very huge file can cause memory pressure by inflating the page cache. Changing the workload to do direct IO can solve this problem, but the modification is not so simple. Jens Axboe thus implemented RWF_UNCACHED flag, which skips use of the page cache if the given IO target is not in the page cache already.
Splitting the mmap_sem https://lkml.kernel.org/r/20191203222147.GV20752@bombadil.infradead.org
The mmap_sem is a big scalability bottleneck and there are several projects for solving it. In this mail, Matthew Wilcox suggests his plan for his solution and asks whether a exceptional case in his solution is acceptable to other people.
Linux 5.5-rc1 https://lkml.kernel.org/r/CAHk-=wiEJK=yo9vEhX_4b4ROvCqUA_rjK7g996h-5MbfOMeDrw@mail.gmail.com
Linux 5.5 merge window closed and the -rc1 has released. It was a tiny bit larger release compared to recent several releases, but fairly regular overall.
[PATCH RFC v3 00/36] Add KernelMemorySanitizer infrastructure https://lkml.kernel.org/r/20191122112621.204798-1-glider@google.com
Google’s third KMSAN RFC patchset that detects errors caused by accessing uninitialized memory areas. Like other SAN series, it has been used in Google syzkaller and found over 200 bugs in the last two years.
LSF/MM/BPF: 2020: Call for Proposals https://lkml.kernel.org/r/20191122172502.vffyfxlqejthjib6@macbook-pro-91.dhcp.thefacebook.com
LSF/MM’s CFP for the next year was released. From next year, BPF sessions will be added to LSF/MM, so the name has changed to LSF/MM/BPF.
[PATCH 00/13] Finish off [smp_]read_barrier_depends() https://lkml.kernel.org/r/20191108170120.22331-1-will@kernel.org
The memory model element which is depends only on Alpha, smp_read_barrier_depends() is built into READ_ONCE(), so that you don’t have to worry about Alpha in non-alpha-specific kernel code. Nevertheless, the author of this patchset concerned about the continuing uploads of the code that cares it. This patchset removes the description of the feature from all documentation and comments in the kernel code.
[PATCH v4 00/10] Add Kernel Concurrency Sanitizer (KCSAN) https://lkml.
Linux 5.4-rc7 https://lkml.kernel.org/r/CAHk-=wivmGEOTha5XkRHgH6VwfiroiN+PFVMNK3B0r-d0eFLPQ@mail.gmail.com
일곱번째 rc 버전이 릴리즈 되었습니다. 지난 rc6 때도 변경량이 생각보다 많아 토발즈가 고민했는데, 이번주도 토발즈가 원했던 것보단 변경량이 많았다고 하는군요. 다음주에 rc8 을 낼지 5.4 정식 버전을 낼지는 좀 더 고민해 봐야겠다고 합니다.
[PATCH V8] mm/debug: Add tests validating architecture page table helpers https://lkml.kernel.org/r/1572240562-23630-1-git-send-email-anshuman.khandual@arm.com
아키텍쳐별 페이지 테이블 헬퍼 등을 테스트 하는 코드를 추가하는 패치입니다. CONFIG_DEBUG_VM_PGTABLE 컨피규레이션이 켜져 있으면 동작합니다.
[PATCH RFC v2 00/25] Add KernelMemorySanitizer infrastructure https://lkml.kernel.org/r/20191030142237.249532-1-glider@google.com
초기화 되지 않은 메모리 영역에 액세스 하는 에러를 찾아주는 KMSAN 을 커널에 추가하는 패치입니다. KCSAN 과 비슷하게 syzkaller 를 통해 돌아가게끔 되어 있군요.
False positive 문제가 존재할 수는 있는 모양입니다만, 구글 내부에서 syzbot 을 통해 테스트 한 환경에서는 중요한 false positive 는 나오지 않은 모양입니다.
[PATCH 00/12] mm: remove __ARCH_HAS_4LEVEL_HACK https://lkml.kernel.org/r/1571822941-29776-1-git-send-email-rppt@kernel.org
서로 다른 아키텍쳐 간의 페이지 테이블 구조로 인해 사용해야 했던 __ARCH_HAS_4LEVEL_HACK 을 제거하는 패치입니다. Alpha, arm, c6x 등의 아키텍쳐가 변경되는군요. UML, qemu 등에서 부팅 테스트를 거쳤군요.
Linux 5.4-rc5 https://lkml.kernel.org/r/CAHk-=wgpewLxHxnO71tFHh=M4C4iUofJykMqq3r=eRyxUyVsiw@mail.gmail.com
다섯번째 rc 버전 릴리즈입니다. 하지만 안타깝게도 이번 릴리즈는 마냥 조용하진 않았다는군요. 최근의 다른 rc5 들에 비하면 조금 큰 크기의 릴리즈가 되었습니다. 그렇다곤 해도 아주 특이할 만한 정도는 아니라 토발즈도 큰 걱정은 없다는군요.