linux-dev/Documentation/features, branch master

Merge tag 'xtensa-20220804' of https://github.com/jcmvbkbc/linux-xtensa

2022-08-04T22:35:58Z

Pull xtensa updates from Max Filippov: - support KCOV - enable ARCH_HAS_GCOV_PROFILE_ALL - minor ISS network driver cleanups * tag 'xtensa-20220804' of https://github.com/jcmvbkbc/linux-xtensa: xtensa: enable ARCH_HAS_GCOV_PROFILE_ALL xtensa: enable KCOV support xtensa: iss: fix handling error cases in iss_net_configure() xtensa: iss/network: provide release() callback xtensa: iss/network: drop 'devices' list

Merge tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

2022-08-03T02:12:45Z

Pull RCU updates from Paul McKenney: - Documentation updates - Miscellaneous fixes - Callback-offload updates, perhaps most notably a new RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be offloaded at boot time, regardless of kernel boot parameters. This is useful to battery-powered systems such as ChromeOS and Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot parameter prevents offloaded callbacks from interfering with real-time workloads and with energy-efficiency mechanisms - Polled grace-period updates, perhaps most notably making these APIs account for both normal and expedited grace periods - Tasks RCU updates, perhaps most notably reducing the CPU overhead of RCU tasks trace grace periods by more than a factor of two on a system with 15,000 tasks. The reduction is expected to increase with the number of tasks, so it seems reasonable to hypothesize that a system with 150,000 tasks might see a 20-fold reduction in CPU overhead - Torture-test updates - Updates that merge RCU's dyntick-idle tracking into context tracking, thus reducing the overhead of transitioning to kernel mode from either idle or nohz_full userspace execution for kernels that track context independently of RCU. This is expected to be helpful primarily for kernels built with CONFIG_NO_HZ_FULL=y * tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (98 commits) rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings rcu: Diagnose extended sync_rcu_do_polled_gp() loops rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings rcutorture: Test polled expedited grace-period primitives rcu: Add polled expedited grace-period primitives rcutorture: Verify that polled GP API sees synchronous grace periods rcu: Make Tiny RCU grace periods visible to polled APIs rcu: Make polled grace-period API account for expedited grace periods rcu: Switch polled grace-period APIs to ->gp_seq_polled rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty rcu/nocb: Add option to opt rcuo kthreads out of RT priority rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread() rcu/nocb: Add an option to offload all CPUs on boot rcu/nocb: Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload() direct call rcu/nocb: Invert rcu_state.barrier_mutex VS hotplug lock locking order rcu/nocb: Add/del rdp to iterate from rcuog itself rcu/tree: Add comment to describe GP-done condition in fqs loop rcu: Initialize first_gp_fqs at declaration in rcu_gp_fqs() rcu/kvfree: Remove useless monitor_todo flag rcu: Cleanup RCU urgency state for offline CPU ...

xtensa: enable ARCH_HAS_GCOV_PROFILE_ALL

2022-07-14T07:54:47Z

Select ARCH_HAS_GCOV_PROFILE_ALL and set GCOV_PROFILE = n inside arch/xtensa/boot/lib. Signed-off-by: Max Filippov

xtensa: enable KCOV support

2022-07-14T07:54:46Z

Select ARCH_HAS_KCOV and set KCOV_INSTRUMENT = n inside arch/xtensa/boot/lib. Signed-off-by: Max Filippov

context_tracking: Split user tracking Kconfig

2022-06-30T00:04:09Z

Context tracking is going to be used not only to track user transitions but also idle/IRQs/NMIs. The user tracking part will then become a separate feature. Prepare Kconfig for that. [ frederic: Apply Max Filippov feedback. ] Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Neeraj Upadhyay Cc: Uladzislau Rezki Cc: Joel Fernandes Cc: Boqun Feng Cc: Nicolas Saenz Julienne Cc: Marcelo Tosatti Cc: Xiongfeng Wang Cc: Yu Liao Cc: Phil Auld Cc: Paul Gortmaker Cc: Alex Belits Signed-off-by: Paul E. McKenney Reviewed-by: Nicolas Saenz Julienne Tested-by: Nicolas Saenz Julienne

arm64: Add HAVE_IOREMAP_PROT support

2022-06-27T11:22:31Z

With ioremap_prot() definition from generic ioremap, also move pte_pgprot() from hugetlbpage.c into pgtable.h, then arm64 could have HAVE_IOREMAP_PROT, which will enable generic_access_phys() code, it is useful for debug, eg, gdb. Acked-by: Catalin Marinas Reviewed-by: Anshuman Khandual Signed-off-by: Kefeng Wang Link: https://lore.kernel.org/r/20220607125027.44946-7-wangkefeng.wang@huawei.com Signed-off-by: Will Deacon

Documentation/features: Update the arch support status files

2022-06-09T15:35:57Z

The arch support status files don't match reality as of v5.19-rc1, use the features-refresh.sh to refresh all the arch-support.txt files in place. The main effect is to add entries for the new loong architecture. Signed-off-by: Zheng Zengkai Link: https://lore.kernel.org/r/20220609025656.143460-1-zhengzengkai@huawei.com Signed-off-by: Jonathan Corbet

Merge tag 'asm-generic-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2022-05-26T17:50:30Z

Pull asm-generic updates from Arnd Bergmann: "The asm-generic tree contains three separate changes for linux-5.19: - The h8300 architecture is retired after it has been effectively unmaintained for a number of years. This is the last architecture we supported that has no MMU implementation, but there are still a few architectures (arm, m68k, riscv, sh and xtensa) that support CPUs with and without an MMU. - A series to add a generic ticket spinlock that can be shared by most architectures with a working cmpxchg or ll/sc type atomic, including the conversion of riscv, csky and openrisc. This series is also a prerequisite for the loongarch64 architecture port that will come as a separate pull request. - A cleanup of some exported uapi header files to ensure they can be included from user space without relying on other kernel headers" * tag 'asm-generic-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: h8300: remove stale bindings and symlink sparc: add asm/stat.h to UAPI compile-test coverage powerpc: add asm/stat.h to UAPI compile-test coverage mips: add asm/stat.h to UAPI compile-test coverage riscv: add linux/bpf_perf_event.h to UAPI compile-test coverage kbuild: prevent exported headers from including , agpgart.h: do not include from exported header csky: Move to generic ticket-spinlock RISC-V: Move to queued RW locks RISC-V: Move to generic spinlocks openrisc: Move to ticket-spinlock asm-generic: qrwlock: Document the spinlock fairness requirements asm-generic: qspinlock: Indicate the use of mixed-size atomics asm-generic: ticket-lock: New generic ticket-based spinlock remove the h8300 architecture

xtensa: enable ARCH_HAS_DEBUG_VM_PGTABLE

2022-05-02T02:51:57Z

xtensa kernels successfully build and run with CONFIG_DEBUG_VM_PGTABLE=y, enable arch support for it. Reviewed-by: Anshuman Khandual Signed-off-by: Max Filippov

xtensa: enable HAVE_VIRT_CPU_ACCOUNTING_GEN

2022-05-02T02:51:22Z

There's no direct cputime_t manipulation in the xtensa arch code, so generic virt CPU accounting may be enabled. Signed-off-by: Max Filippov