RISC-V Linux 内核及周边技术动态第 97 期

时间：20240623
编辑：晓瑜
仓库：RISC-V Linux 内核技术调研活动
赞助：PLCT Lab, ISCAS

内核动态

RISC-V 架构支持

v1: riscv: allwinner: ClockworkPi and DevTerm devicetrees

The regulator bindings were recently resent and landed , so now is the time to get the rest of the stragglers in.

v3: RISC-V: Provide the frequency of time CSR via hwprobe

A handful of user-visible behavior is based on the frequency of the time CSR.

[PATCH RESEND bpf-next v4 0/3] Add 12-argument support for RV64 bpf trampoline

This patch adds 12 function arguments support for riscv64 bpf trampoline.

v2: riscv: Idle thread using Zawrs extension

This is the second version of idle thread based on Zawrs extension.

v5: riscv: Optimize crc32 with Zbc extension

As suggested by the B-ext spec, the Zbc (carry-less multiplication) instructions can be used to accelerate CRC calculations.

v3: riscv: Add support for xtheadvector

xtheadvector is a custom extension that is based upon riscv vector version 0.7.1 . All of the vector routines have been modified to support this alternative vector version based upon whether xtheadvector was determined to be supported at boot.

v1: riscv: add support for Zaamo and Zalrsc extensions

Since commit e87412e621f1 (“integrate Zaamo and Zalrsc text (#1304)”), the A extension has been described as a set of instructions provided by Zaamo and Zalrsc. Add these two extensions.

v7: Add support for a few Zc* extensions, Zcmop and Zimop

Add support for (yet again) more RVA23U64 missing extensions. Add support for Zimop, Zcmop, Zca, Zcf, Zcd and Zcb extensions ISA string parsing, hwprobe and kvm support.

v1: riscv: sophgo: add mailbox support for cv18x SoCs

Add mailbox support for Sophgo cv18x SoCs, and test on both cv1800b SoC for milkv-duo and cv1812h SoC for milkv-duo256m

v1: RISC-V: cmdline: Add support for ‘memmap’ parameter

Implement support for parsing ‘memmap’ kernel command line parameter.

v1: RISC-V: Provide the frequency of mtime via hwprobe

A handful of user-visible behavior is based on the frequency of the machine-mode time.

v4: mmc: sdhci-of-dwcmshc: Add Sophgo SG2042 support

The reason for merging the two parts into one patchset is mainly to facilitate review, especially to facilitate viewing why we need to improve the framework and what benefits it will bring to us.

v3: Add I2C support on TH1520

This adds I2C support in the device tree of the T-Head TH1520 RISCV-SoC and a default configuration for the BeagleV-Ahead.

v1: riscv: enable HAVE_ARCH_STACKLEAK

Add support for the stackleak feature. Whenever the kernel returns to user space the kernel stack is filled with a poison value.

v1: riscv: add initial support for SpacemiT K1

Add initial support for it to allow more people to participate in building drivers to mainline for it.

v1: clk: thead: Add support for TH1520 AP_SUBSYS clock controller

This series adds support for the AP sub-system clock controller in the T-Head TH1520 . Yangtao Li originally submitted this series in May work in progress to me.

LoongArch 架构支持

v1: LoongArch: KVM: Sync pending interrupt when getting ESTAT from user mode

Currently interrupt is posted and cleared with async mode, and it is saved in SW state vcpu::arch::irq_pending and vcpu::arch::irq_clear.

v1: LoongArch: Always enumerate MADT and setup logical-physical CPU mapping

Some drivers want to use cpu_logical_map(), early_cpu_to_node() and some other CPU mapping APIs, even if we use “nr_cpus=1” to hard limit the CPU number.

进程调度

v4: perf sched map: Add command-name, fuzzy-name options to filter the output map

By default, perf sched map prints sched-in events for all the tasks which may not be required all the time as it prints lot of symbols and rows to the terminal.

v1: freezer,sched: Preventing kthreads with D-state from being woken up during freeze

Sometimes althought a kthread was set to be freezable, the thread’s state also could be TASK_UNINTERRUPTIBLE because of some blocked reasons, such as msleep, wait_for_complete, mutex and so on…

内存管理

v2: tools/mm: Introduce a tool to assess swap entry allocation for thp_swapout

we’re rarely hitting 100% even in the worst case without “-a” and with “-s,” which is good news!

v2: mm/gup: Clear the LRU flag of a page before adding to LRU batch

To solve the problem above, we modify the logic of adding to LRU batch.

v1: mm: rename no_progress_loops to reclaim_retries. variable no_progress_loops exectly means reclaim retry counts, renameing makes it easier to understand. and has the same style as variable compaction_retries.

v1: add support for mm-local memory allocations

In a series posted a few years ago , a proposal was put forward to allow the kernel to allocate memory local to a mm and thus push it out of reach for current and future speculation-based cross-process attacks.

v1: hugetlb: force allocating surplus hugepages on mempolicy allowed nodes

So allocate surplus hugepages in one of the nodes the current process belongs to.

v2: mm/zsmalloc: change back to per-size_class lock

v1: add zpdesc memory descriptor for zswap.zpool

According to Metthew’s plan, the page descriptor will be replace by a 8 bytes mem_desc on destination purpose.

v3: Improve the copy of task comm

This approach will facilitate future extensions to the task comm.

v2: filemap: add trace events for get_pages, map_pages, and fault

To allow precise tracking of page caches accessed, add new tracepoints that trigger when a process actually accesses them.

v2: mm: ksm: Consider the number of ksm_mm_slot in the general_profit calculation

This patch introduces a new variable to keep track of the number of allocated ksm_mm_slots. By doing so, KSM will be able to provide a more accurate number of the gains made.

v2: mm/migrate: make migrate_pages_batch() stats consistent.

As Ying pointed out in, stats->nr_thp_failed needs to be updated to avoid stats inconsistency between MIGRATE_SYNC and MIGRATE_ASYNC when calling migrate_pages_batch().

v2: mm/page_alloc: Separate THP PCP into movable and non-movable categories

Since commit 5d0a661d808f (“mm/page_alloc: use only one PCP list for THP-sized allocations”) no longer differentiates the migration type of pages in THP-sized PCP list, it’s possible that non-movable allocation requests may get a CMA page from the list, in some cases, it’s not acceptable.