lwn.git/tools, branch docs-5.2a

docs: livepatch: convert docs to ReST and rename to *.rst

2019-05-07T22:05:49+00:00

Convert livepatch documentation to ReST format. The changes are mostly trivial, as the documents are already on a good shape. Just a few markup changes are needed for Sphinx to properly parse the docs. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - The in-file TOC becomes a comment, in order to skip it from the output, as Sphinx already generates an index there. - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Petr Mladek Acked-by: Miroslav Benes Acked-by: Josh Poimboeuf Acked-by: Joe Lawrence Reviewed-by: Kamalesh Babulal Signed-off-by: Jonathan Corbet

Merge tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

2019-03-16T20:47:14+00:00

Pull pidfd system call from Christian Brauner: "This introduces the ability to use file descriptors from /proc// as stable handles on struct pid. Even if a pid is recycled the handle will not change. For a start these fds can be used to send signals to the processes they refer to. With the ability to use /proc/ fds as stable handles on struct pid we can fix a long-standing issue where after a process has exited its pid can be reused by another process. If a caller sends a signal to a reused pid it will end up signaling the wrong process. With this patchset we enable a variety of use cases. One obvious example is that we can now safely delegate an important part of process management - sending signals - to processes other than the parent of a given process by sending file descriptors around via scm rights and not fearing that the given process will have been recycled in the meantime. It also allows for easy testing whether a given process is still alive or not by sending signal 0 to a pidfd which is quite handy. There has been some interest in this feature e.g. from systems management (systemd, glibc) and container managers. I have requested and gotten comments from glibc to make sure that this syscall is suitable for their needs as well. In the future I expect it to take on most other pid-based signal syscalls. But such features are left for the future once they are needed. This has been sitting in linux-next for quite a while and has not caused any issues. It comes with selftests which verify basic functionality and also test that a recycled pid cannot be signaled via a pidfd. Jon has written about a prior version of this patchset. It should cover the basic functionality since not a lot has changed since then: https://lwn.net/Articles/773459/ The commit message for the syscall itself is extensively documenting the syscall, including it's functionality and extensibility" * tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: selftests: add tests for pidfd_send_signal() signal: add pidfd_send_signal() syscall

Merge tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2019-03-16T20:05:32+00:00

Pull device-dax updates from Dan Williams: "New device-dax infrastructure to allow persistent memory and other "reserved" / performance differentiated memories, to be assigned to the core-mm as "System RAM". Some users want to use persistent memory as additional volatile memory. They are willing to cope with potential performance differences, for example between DRAM and 3D Xpoint, and want to use typical Linux memory management apis rather than a userspace memory allocator layered over an mmap() of a dax file. The administration model is to decide how much Persistent Memory (pmem) to use as System RAM, create a device-dax-mode namespace of that size, and then assign it to the core-mm. The rationale for device-dax is that it is a generic memory-mapping driver that can be layered over any "special purpose" memory, not just pmem. On subsequent boots udev rules can be used to restore the memory assignment. One implication of using pmem as RAM is that mlock() no longer keeps data off persistent media. For this reason it is recommended to enable NVDIMM Security (previously merged for 5.0) to encrypt pmem contents at rest. We considered making this recommendation an actively enforced requirement, but in the end decided to leave it as a distribution / administrator policy to allow for emulation and test environments that lack security capable NVDIMMs. Summary: - Replace the /sys/class/dax device model with /sys/bus/dax, and include a compat driver so distributions can opt-in to the new ABI. - Allow for an alternative driver for the device-dax address-range - Introduce the 'kmem' driver to hotplug / assign a device-dax address-range to the core-mm. - Arrange for the device-dax target-node to be onlined so that the newly added memory range can be uniquely referenced by numa apis" NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because we currently have special - and very annoying rules in the kernel about accessing PMEM only with the "MC safe" accessors, because machine checks inside the regular repeat string copy functions can be fatal in some (not described) circumstances. And apparently the PMEM modules can cause that a lot more than regular RAM. The argument is that this happens because PMEM doesn't necessarily get scrubbed at boot like RAM does, but that is planned to be added for the user space tooling. Quoting Dan from another email: "The exposure can be reduced in the volatile-RAM case by scanning for and clearing errors before it is onlined as RAM. The userspace tooling for that can be in place before v5.1-final. There's also runtime notifications of errors via acpi_nfit_uc_error_notify() from background scrubbers on the DIMM devices. With that mechanism the kernel could proactively clear newly discovered poison in the volatile case, but that would be additional development more suitable for v5.2. I understand the concern, and the need to highlight this issue by tapping the brakes on feature development, but I don't see PMEM as RAM making the situation worse when the exposure is also there via DAX in the PMEM case. Volatile-RAM is arguably a safer use case since it's possible to repair pages where the persistent case needs active application coordination" * tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: device-dax: "Hotplug" persistent memory for use like normal RAM mm/resource: Let walk_system_ram_range() search child resources mm/memory-hotplug: Allow memory resources to be children mm/resource: Move HMM pr_debug() deeper into resource code mm/resource: Return real error codes from walk failures device-dax: Add a 'modalias' attribute to DAX 'bus' devices device-dax: Add a 'target_node' attribute device-dax: Auto-bind device after successful new_id acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node device-dax: Add /sys/class/dax backwards compatibility device-dax: Add support for a dax override driver device-dax: Move resource pinning+mapping into the common driver device-dax: Introduce bus + driver model device-dax: Start defining a dax bus model device-dax: Remove multi-resource infrastructure device-dax: Kill dax_region base device-dax: Kill dax_region ida

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2019-03-15T22:00:28+00:00

Pull KVM updates from Paolo Bonzini: "ARM: - some cleanups - direct physical timer assignment - cache sanitization for 32-bit guests s390: - interrupt cleanup - introduction of the Guest Information Block - preparation for processor subfunctions in cpu models PPC: - bug fixes and improvements, especially related to machine checks and protection keys x86: - many, many cleanups, including removing a bunch of MMU code for unnecessary optimizations - AVIC fixes Generic: - memcg accounting" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (147 commits) kvm: vmx: fix formatting of a comment KVM: doc: Document the life cycle of a VM and its resources MAINTAINERS: Add KVM selftests to existing KVM entry Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()" KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char() KVM: PPC: Fix compilation when KVM is not enabled KVM: Minor cleanups for kvm_main.c KVM: s390: add debug logging for cpu model subfunctions KVM: s390: implement subfunction processor calls arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2 KVM: arm/arm64: Remove unused timer variable KVM: PPC: Book3S: Improve KVM reference counting KVM: PPC: Book3S HV: Fix build failure without IOMMU support Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()" x86: kvmguest: use TSC clocksource if invariant TSC is exposed KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns KVM: x86/mmu: Consolidate kvm_mmu_zap_all() and kvm_mmu_zap_mmio_sptes() KVM: x86/mmu: WARN if zapping a MMIO spte results in zapping children ...

Merge branch 'akpm' (patches from Andrew)

2019-03-14T22:10:10+00:00

Merge misc patches from Andrew Morton: - a little bit more MM - a few fixups [ The "little bit more MM" is actually just one of the three patches Andrew sent for mm/filemap.c, I'm still mulling over two more of them from Josef Bacik - Linus ] * emailed patches from Andrew Morton : include/linux/swap.h: use offsetof() instead of custom __swapoffset macro tools/testing/selftests/proc/proc-pid-vm.c: test with vsyscall in mind zram: default to lzo-rle instead of lzo filemap: pass vm_fault to the mmap ra helpers

tools/testing/selftests/proc/proc-pid-vm.c: test with vsyscall in mind

2019-03-14T21:36:20+00:00

: selftests: proc: proc-pid-vm : ======================================== : proc-pid-vm: proc-pid-vm.c:277: main: Assertion `rv == strlen(buf0)' failed. : Aborted Because the vsyscall mapping is enabled. Read from vsyscall page to tell if vsyscall is being used. Link: http://lkml.kernel.org/r/20190307183204.GA11405@avx2 Link: http://lkml.kernel.org/r/20190219094722.GB28258@shao2-debian Fixes: 34aab6bec23e7e9 ("proc: test /proc/*/maps, smaps, smaps_rollup, statm") Signed-off-by: Alexey Dobriyan Reported-by: kernel test robot Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2019-03-14T17:30:06+00:00

Pull more power management updates from Rafael Wysocki: "These are mostly fixes and cleanups on top of the previously merged power management material for 5.1-rc1 with one cpupower utility update that wasn't pushed earlier due to unfortunate timing. Specifics: - Fix registration of new cpuidle governors partially broken during the 5.0 development cycle by mistake (Rafael Wysocki). - Avoid integer overflows in the menu cpuidle governor by making it discard the overflowing data points upfront (Rafael Wysocki). - Fix minor mistake in the recent update of the iowait boost computation in the intel_pstate driver (Rafael Wysocki). - Drop incorrect __init annotation from one function in the pxa2xx cpufreq driver (Arnd Bergmann). - Fix the operating performance points (OPP) framework initialization for devices in multiple power domains if only one of them is scalable (Rajendra Nayak). - Fix mistake in dev_pm_opp_set_rate() which causes it to skip updating the performance state if the new frequency is the same as the old one (Viresh Kumar). - Rework the cancellation of wakeup source timers to avoid potential issues with it and do some cleanups unlocked by that change (Viresh Kumar, Rafael Wysocki). - Clean up the code computing the active/suspended time of devices in the PM-runtime framework after recent changes (Ulf Hansson). - Make the power management infrastructure code use pr_fmt() consistently (Joe Perches). - Clean up the generic power domains (genpd) framework somewhat (Aisheng Dong). - Improve kerneldoc comments for two functions in the cpufreq core (Rafael Wysocki). - Fix typo in a PM QoS file description comment (Aisheng Dong). - Update the handling of CPU boost frequencies in the cpupower utility (Abhishek Goel)" * tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpuidle: governor: Add new governors to cpuidle_governors again cpufreq: intel_pstate: Fix up iowait_boost computation PM / OPP: Update performance state when freq == old_freq PM / wakeup: Drop wakeup_source_drop() PM / wakeup: Rework wakeup source timer cancellation PM / domains: Remove one unnecessary blank line PM / Domains: Return early for all errors in _genpd_power_off() PM / Domains: Improve warn for multiple states but no governor OPP: Fix handling of multiple power domains PM / QoS: Fix typo in file description cpufreq: pxa2xx: remove incorrect __init annotation PM-runtime: Call pm_runtime_active|suspended_time() from sysfs PM-runtime: Consolidate code to get active/suspended time PM: Add and use pr_fmt() cpufreq: Improve kerneldoc comments for cpufreq_cpu_get/put() cpuidle: menu: Avoid overflows when computing variance tools/power/cpupower: Display boost frequency separately

Merge branches 'pm-opp' and 'pm-tools'

2019-03-14T09:53:22+00:00

* pm-opp: PM / OPP: Update performance state when freq == old_freq OPP: Fix handling of multiple power domains * pm-tools: tools/power/cpupower: Display boost frequency separately

Merge branch 'akpm' (patches from Andrew)

2019-03-12T17:39:53+00:00

Merge misc updates from Andrew Morton: - a few misc things - the rest of MM - remove flex_arrays, replace with new simple radix-tree implementation * emailed patches from Andrew Morton : (38 commits) Drop flex_arrays sctp: convert to genradix proc: commit to genradix generic radix trees selinux: convert to kvmalloc md: convert to kvmalloc openvswitch: convert to kvmalloc of: fix kmemleak crash caused by imbalance in early memory reservation mm: memblock: update comments and kernel-doc memblock: split checks whether a region should be skipped to a helper function memblock: remove memblock_{set,clear}_region_flags memblock: drop memblock_alloc_*_nopanic() variants memblock: memblock_alloc_try_nid: don't panic treewide: add checks for the return value of memblock_alloc*() swiotlb: add checks for the return value of memblock_alloc*() init/main: add checks for the return value of memblock_alloc*() mm/percpu: add checks for the return value of memblock_alloc*() sparc: add checks for the return value of memblock_alloc*() ia64: add checks for the return value of memblock_alloc*() arch: don't memset(0) memory returned by memblock_alloc() ...

Drop flex_arrays

2019-03-12T17:04:03+00:00

All existing users have been converted to generic radix trees Link: http://lkml.kernel.org/r/20181217131929.11727-8-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet Acked-by: Dave Hansen Cc: Alexey Dobriyan Cc: Al Viro Cc: Eric Paris Cc: Marcelo Ricardo Leitner Cc: Matthew Wilcox Cc: Neil Horman Cc: Paul Moore Cc: Pravin B Shelar Cc: Shaohua Li Cc: Stephen Smalley Cc: Vlad Yasevich Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds