Re: [PATCH 2/3] x86/alternatives,jump_label: Provide better text_poke() batching interface

Hi Peter, On Tue, 27 Aug 2019 20:06:24 +0200 Peter Zijlstra wrote: > Adding another text_poke_bp_batch() user made me realize the interface > is all sorts of wrong. The text poke vector should be internal to the > implementation. > > This then results in a trivial interface: > >

Re: [PATCH 3/3] x86/ftrace: Use text_poke()

On Wed, 2 Oct 2019 18:35:26 +0200 Daniel Bristot de Oliveira wrote: > ftrace was already batching the updates, for instance, causing 3 IPIs to > enable > all functions. The text_poke() batching also works. But because of the limited > buffer [ see the reply to the patch 2/3 ], it is flushing

RE: [PATCH] Input: hyperv-keyboard: Add the support of hibernation

> From: dmitry.torok...@gmail.com > Sent: Monday, September 30, 2019 4:07 PM > > On Mon, Sep 30, 2019 at 10:09:27PM +, Dexuan Cui wrote: > > > From: dmitry.torok...@gmail.com > > > Sent: Friday, September 27, 2019 5:32 PM > > > > ... > > > > pm_wakeup_pending() is tested in a lot of places

Re: [PATCH v2 00/21] Refine memblock API

(trimmed the CC) On Wed, Oct 02, 2019 at 06:14:11AM -0500, Adam Ford wrote: > On Wed, Oct 2, 2019 at 2:36 AM Mike Rapoport wrote: > > > > Before the patch: > > # cat /sys/kernel/debug/memblock/memory >0: 0x1000..0x8fff > # cat /sys/kernel/debug/memblock/reserved >0:

Re: [PATCH v3 2/3] media: i2c: Add IMX290 CMOS image sensor driver

Hi Sakari, On Wed, Oct 02, 2019 at 01:37:15PM +0300, Sakari Ailus wrote: > Hi Manivannan, > > On Wed, Oct 02, 2019 at 12:12:00AM +0530, Manivannan Sadhasivam wrote: > > Hi Sakari, > > > > On Mon, Sep 23, 2019 at 12:22:09PM +0300, Sakari Ailus wrote: > > > Hi Manivannan, > > > > > > On Fri, Aug

Re: [PATCH v2 3/3] RISC-V: Move SBI related macros under uapi.

On Sat, Sep 28, 2019 at 3:51 AM Christoph Hellwig wrote: > > On Thu, Sep 26, 2019 at 05:09:15PM -0700, Atish Patra wrote: > > All SBI related macros can be reused by KVM RISC-V and userspace tools > > such as kvmtool, qemu-kvm. SBI calls can also be emulated by userspace > > if required. Any

Re: [rfc] mm, hugetlb: allow hugepage allocations to excessively reclaim

On Wed 02-10-19 16:03:03, David Rientjes wrote: > Hugetlb allocations use __GFP_RETRY_MAYFAIL to aggressively attempt to get > hugepages that the user needs. Commit b39d0ee2632d ("mm, page_alloc: > avoid expensive reclaim when compaction may not succeed") intends to > improve allocator behind

Re: [PATCH 1/2] misc: add cc1101 devicetree binding

Hello Rob, Am 02.10.2019 um 16:19 schrieb Rob Herring: On Sun, Sep 22, 2019 at 08:03:55AM +0200, Heiko Schocher wrote: add devicetree binding for cc1101 misc driver. Signed-off-by: Heiko Schocher --- .../devicetree/bindings/misc/cc1101.txt | 27 +++ 1 file changed,

Re: [PATCH v2 0/3] media: cedrus: improvements

Dne četrtek, 03. oktober 2019 ob 00:23:07 CEST je Paul Kocialkowski napisal(a): > Hi, > > On Wed 02 Oct 19, 21:35, Jernej Skrabec wrote: > > This is continuation of https://lkml.org/lkml/2019/5/30/1459 with several > > patches removed (2 merged, others needs redesign) and one added. > > Thanks

Re: [PATCH] dt-bindings: memory-controllers: exynos5422-dmc: Correct example syntax and memory region

Hi Krzysztof, On 10/2/19 7:44 PM, Krzysztof Kozlowski wrote: > After adding the interrupt properties to Exynos5422 DMC bindings > example, the mapped memory region must be big enough to access > performance counters registers. > > Fix also syntax errors (semicolons) and adjust indentation. > >

Re: [PATCH v2 2/3] RISC-V: Add basic support for SBI v0.2

On Fri, Sep 27, 2019 at 5:39 AM Atish Patra wrote: > > The SBI v0.2 introduces a base extension which is backward compatible > with v0.1. Implement all helper functions and minimum required SBI > calls from v0.2 for now. All other base extension function will be > added later as per need. > As

Re: [PATCH v2 2/3] media: cedrus: Fix H264 default reference index count

Dne četrtek, 03. oktober 2019 ob 00:06:50 CEST je Paul Kocialkowski napisal(a): > Hi, > > On Wed 02 Oct 19, 21:35, Jernej Skrabec wrote: > > Reference index count in VE_H264_PPS should come from PPS control. > > However, this is not really important, because reference index count is > > in our

[PATCH v8 19/19] RISC-V: KVM: Add MAINTAINERS entry

Add myself as maintainer for KVM RISC-V and Atish as designated reviewer. Signed-off-by: Atish Patra Signed-off-by: Anup Patel Acked-by: Paolo Bonzini Reviewed-by: Paolo Bonzini Reviewed-by: Alexander Graf --- MAINTAINERS | 10 ++ 1 file changed, 10 insertions(+) diff --git

[PATCH v8 17/19] RISC-V: KVM: Forward unhandled SBI calls to userspace

Instead of returning error to Guest for unhandled SBI calls, we should forward such SBI calls to KVM user-space tool (QEMU/KVMTOOL). This way KVM userspace tool can do something about unhandled SBI calls: 1. Print unhandled SBI call details and kill the Guest 2. Emulate unhandled SBI call and

[PATCH v8 18/19] RISC-V: KVM: Document RISC-V specific parts of KVM API.

Document RISC-V specific parts of the KVM API, such as: - The interrupt numbers passed to the KVM_INTERRUPT ioctl. - The states supported by the KVM_{GET,SET}_MP_STATE ioctls. - The registers supported by the KVM_{GET,SET}_ONE_REG interface and the encoding of those register ids. - The exit

[PATCH v8 13/19] RISC-V: KVM: Add timer functionality

From: Atish Patra The RISC-V hypervisor specification doesn't have any virtual timer feature. Due to this, the guest VCPU timer will be programmed via SBI calls. The host will use a separate hrtimer event for each guest VCPU to provide timer functionality. We inject a virtual timer interrupt to

[PATCH v8 11/19] RISC-V: KVM: Implement stage2 page table programming

This patch implements all required functions for programming the stage2 page table for each Guest/VM. At high-level, the flow of stage2 related functions is similar from KVM ARM/ARM64 implementation but the stage2 page table format is quite different for KVM RISC-V. Signed-off-by: Anup Patel

[PATCH v8 10/19] RISC-V: KVM: Implement VMID allocator

We implement a simple VMID allocator for Guests/VMs which: 1. Detects number of VMID bits at boot-time 2. Uses atomic number to track VMID version and increments VMID version whenever we run-out of VMIDs 3. Flushes Guest TLBs on all host CPUs whenever we run-out of VMIDs 4. Force updates HW

[PATCH v8 15/19] RISC-V: KVM: Implement ONE REG interface for FP registers

From: Atish Patra Add a KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctl interface for floating point registers such as F0-F31 and FCSR. This support is added for both 'F' and 'D' extensions. Signed-off-by: Atish Patra Signed-off-by: Anup Patel Acked-by: Paolo Bonzini Reviewed-by: Paolo Bonzini

[PATCH v8 14/19] RISC-V: KVM: FP lazy save/restore

From: Atish Patra This patch adds floating point (F and D extension) context save/restore for guest VCPUs. The FP context is saved and restored lazily only when kernel enter/exits the in-kernel run loop and not during the KVM world switch. This way FP save/restore has minimal impact on KVM

[PATCH v8 16/19] RISC-V: KVM: Add SBI v0.1 support

From: Atish Patra The KVM host kernel running in HS-mode needs to handle SBI calls coming from guest kernel running in VS-mode. This patch adds SBI v0.1 support in KVM RISC-V. All the SBI calls are implemented correctly except remote tlb flushes. For remote TLB flushes, we are doing full TLB

[PATCH v8 12/19] RISC-V: KVM: Implement MMU notifiers

This patch implements MMU notifiers for KVM RISC-V so that Guest physical address space is in-sync with Host physical address space. This will allow swapping, page migration, etc to work transparently with KVM RISC-V. Signed-off-by: Anup Patel Acked-by: Paolo Bonzini Reviewed-by: Paolo Bonzini

[PATCH v8 06/19] RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls

For KVM RISC-V, we use KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls to access VCPU config and registers from user-space. We have three types of VCPU registers: 1. CONFIG - these are VCPU config and capabilities 2. CORE - these are VCPU general purpose registers 3. CSR- these are VCPU control and

[PATCH v8 08/19] RISC-V: KVM: Handle MMIO exits for VCPU

We will get stage2 page faults whenever Guest/VM access SW emulated MMIO device or unmapped Guest RAM. This patch implements MMIO read/write emulation by extracting MMIO details from the trapped load/store instruction and forwarding the MMIO read/write to user-space. The actual MMIO emulation

[PATCH v8 07/19] RISC-V: KVM: Implement VCPU world-switch

This patch implements the VCPU world-switch for KVM RISC-V. The KVM RISC-V world-switch (i.e. __kvm_riscv_switch_to()) mostly switches general purpose registers, SSTATUS, STVEC, SSCRATCH and HSTATUS CSRs. Other CSRs are switched via vcpu_load() and vcpu_put() interface in kvm_arch_vcpu_load() and

[PATCH v8 09/19] RISC-V: KVM: Handle WFI exits for VCPU

We get illegal instruction trap whenever Guest/VM executes WFI instruction. This patch handles WFI trap by blocking the trapped VCPU using kvm_vcpu_block() API. The blocked VCPU will be automatically resumed whenever a VCPU interrupt is injected from user-space or from in-kernel IRQCHIP

[PATCH v8 01/19] RISC-V: Add bitmap reprensenting ISA features common across CPUs

This patch adds riscv_isa bitmap which represents Host ISA features common across all Host CPUs. The riscv_isa is not same as elf_hwcap because elf_hwcap will only have ISA features relevant for user-space apps whereas riscv_isa will have ISA features relevant to both kernel and user-space apps.

[PATCH v8 02/19] RISC-V: Add hypervisor extension related CSR defines

This patch extends asm/csr.h by adding RISC-V hypervisor extension related defines. Signed-off-by: Anup Patel Acked-by: Paolo Bonzini Reviewed-by: Paolo Bonzini Reviewed-by: Alexander Graf --- arch/riscv/include/asm/csr.h | 58 1 file changed, 58

[PATCH v8 04/19] RISC-V: KVM: Implement VCPU create, init and destroy functions

This patch implements VCPU create, init and destroy functions required by generic KVM module. We don't have much dynamic resources in struct kvm_vcpu_arch so these functions are quite simple for KVM RISC-V. Signed-off-by: Anup Patel Acked-by: Paolo Bonzini Reviewed-by: Paolo Bonzini

[PATCH v8 05/19] RISC-V: KVM: Implement VCPU interrupts and requests handling

This patch implements VCPU interrupts and requests which are both asynchronous events. The VCPU interrupts can be set/unset using KVM_INTERRUPT ioctl from user-space. In future, the in-kernel IRQCHIP emulation will use kvm_riscv_vcpu_set_interrupt() and kvm_riscv_vcpu_unset_interrupt() functions

[PATCH v8 00/19] KVM RISC-V Support

This series adds initial KVM RISC-V support. Currently, we are able to boot RISC-V 64bit Linux Guests with multiple VCPUs. Few key aspects of KVM RISC-V added by this series are: 1. Minimal possible KVM world-switch which touches only GPRs and few CSRs. 2. Full Guest/VM switch is done via

[PATCH v8 03/19] RISC-V: Add initial skeletal KVM support

This patch adds initial skeletal KVM RISC-V support which has: 1. A simple implementation of arch specific VM functions except kvm_vm_ioctl_get_dirty_log() which will implemeted in-future as part of stage2 page loging. 2. Stubs of required arch specific VCPU functions except

Re: [PATCH 1/3] x86/alternatives: Teach text_poke_bp() to emulate instructions

Hi Peter, On Tue, 27 Aug 2019 20:06:23 +0200 Peter Zijlstra wrote: > In preparation for static_call and variable size jump_label support, > teach text_poke_bp() to emulate instructions, namely: > > JMP32, JMP8, CALL, NOP2, NOP_ATOMIC5 > > The current text_poke_bp() takes a @handler argument

Re: [rfc] mm, hugetlb: allow hugepage allocations to excessively reclaim

On Wed 02-10-19 16:37:57, Linus Torvalds wrote: > On Wed, Oct 2, 2019 at 4:03 PM David Rientjes wrote: > > > > Since hugetlb allocations have explicitly preferred to loop and do reclaim > > and compaction, exempt them from this new behavior at least for the time > > being. It is not shown that

Re: [PATCH RFC] reboot: hotplug cpus in migrate_to_reboot_cpu()

On Wed, Oct 2, 2019 at 7:41 PM Hsin-Yi Wang wrote: > > Currently system reboots use arch specific codes (eg. smp_send_stop) to > offline non reboot cpus. Some arch like arm64, arm, and x86... set offline > masks to cpu without really offlining them. Thus it causes some race > condition and kernel

[PATCH] ALSA: hda/realtek: Reduce the Headphone static noise on XPS 9350/9360

Headphone on XPS 9350/9360 produces a background white noise. The The noise level somehow correlates with "Headphone Mic Boost", when it sets to 1 the noise disappears. However, doing this has a side effect, which also decreases the overall headphone volume so I didn't send the patch upstream.

linux-next: Tree for Oct 3

Hi all, Changes since 20191002: New tree: tomoyo My fixes tree contains: 04e6dac68d9b ("powerpc/64s/radix: fix for "tidy up TLB flushing code" and !CONFIG_PPC_RADIX_MMU") The amdgpu tree gained a conflict against Linus' tree. The keys tree with gained a conflict aga

[PATCH] arm64: dts: qcom: sdm845: Add APSS watchdog node

Add a node describing the watchdog found in the application subsystem. Signed-off-by: Bjorn Andersson --- arch/arm64/boot/dts/qcom/sdm845.dtsi | 6 ++ 1 file changed, 6 insertions(+) diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi index

[PATCH v1 0/2] mmc: sdhci-of-arasan: Add Support for Intel LGM SDXC

The current arasan sdhci PHY configuration isn't compatible with the PHY on Intel's LGM(Lightning Mountain) SoC devices. Therefore, add a new compatible, to adapt the Intel's LGM SDXC PHY with arasan-sdhc controller to configure the PHY. Linux code base : V5.4-rc1 Ramuthevar Vadivel Murugan

[PATCH v1 1/2] dt-bindings: mmc: sdhci-of-arasan: Add new compatible for Intel LGM SDXC

From: Ramuthevar Vadivel Murugan Add a new compatible to use the sdhc-arasan host controller driver with the eMMC PHY on Intel's Lightning Mountain(LGM) SoC. Signed-off-by: Ramuthevar Vadivel Murugan --- Documentation/devicetree/bindings/mmc/arasan,sdhci.txt | 17 + 1 file

[PATCH v1 2/2] mmc: sdhci-of-arasan: Add Support for Intel LGM SDXC

From: Ramuthevar Vadivel Murugan The current arasan sdhci PHY configuration isn't compatible with the PHY on Intel's LGM(Lightning Mountain) SoC devices. Therefore, add a new compatible, to adapt the Intel's LGM SDXC PHY with arasan-sdhc controller to configure the PHY. Signed-off-by:

[PATCH] vfio/type1: remove hugepage checks in is_invalid_reserved_pfn()

Currently, no hugepage split code can transfer the reserved bit from head to tail during the split, so checking the head can't make a difference in a racing condition with hugepage spliting. The buddy wouldn't allow a driver to allocate an hugepage if any subpage is reserved in the e820 map at

RE: [PATCH] can: m_can: add support for one shot mode

Gentle Ping > -Original Message- > From: Pankaj Sharma > Subject: [PATCH] can: m_can: add support for one shot mode > > According to the CAN Specification (see ISO 11898-1:2015, 8.3.4 Recovery > Management), the M_CAN provides means for automatic retransmission of > frames that have

Re: [PATCH 0/3] PCI: pciehp: Do not turn off slot if presence comes up after link

On Wed, Oct 02, 2019 at 05:13:58PM -0500, Alex G. wrote: > On 10/1/19 11:13 PM, Lukas Wunner wrote: > > On Tue, Oct 01, 2019 at 05:14:16PM -0400, Stuart Hayes wrote: > > > This patch set is based on a patch set [1] submitted many months ago by > > > Alexandru Gagniuc, who is no longer working on

KMSAN: uninit-value in cxusb_rc_query

Hello, syzbot found the following crash on: HEAD commit:cebbfdbc kmsan: merge set_no_shadow_page() and set_no_orig.. git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=1277527e60 kernel config:

KMSAN: uninit-value in sr9800_bind

Hello, syzbot found the following crash on: HEAD commit:124037e0 kmsan: drop inlines, rename do_kmsan_task_create() git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=10f7e0cd60 kernel config:

Re: Stop breaking the CSRNG

On Wed, Oct 02, 2019 at 06:55:33PM +0200, Kurt Roeckx wrote: > > But it seems people are now thinking about breaking getrandom() too, > to let it return data when it's not initialized by default. Please > don't. "It's complicated" The problem is that whether a CRNG can be considered secure is a

[RFC][PATCH] dt-bindings: usb: rt1711h: Add connector bindings

Add connector binding documentation for Richtek RT1711H Type-C chip driver It was noted by Rob Herring that the rt1711h binding docs doesn't include the connector binding. Thus this patch adds such documentation following the details in Documentation/devicetree/bindings/usb/typec-tcpci.txt CC:

[PATCH 2/2] HID: google: Detect base folded usage instead of hard-coding whiskers

Some other hammer-like device will emit a similar code, let's look for the folded event in HID usage table, instead of hard-coding whiskers in many places. Signed-off-by: Nicolas Boichat --- drivers/hid/hid-google-hammer.c | 53 - 1 file changed, 25

[PATCH 1/2] HID: google: add magnemite/masterball USB ids

Add 2 additional hammer-like devices. Signed-off-by: Nicolas Boichat --- drivers/hid/hid-google-hammer.c | 4 drivers/hid/hid-ids.h | 2 ++ 2 files changed, 6 insertions(+) diff --git a/drivers/hid/hid-google-hammer.c b/drivers/hid/hid-google-hammer.c index

[PATCH RFC] reboot: hotplug cpus in migrate_to_reboot_cpu()

Currently system reboots use arch specific codes (eg. smp_send_stop) to offline non reboot cpus. Some arch like arm64, arm, and x86... set offline masks to cpu without really offlining them. Thus it causes some race condition and kernel warning comes out sometimes when system reboots. We can do

[PATCH v2] kbuild: update compile-test header list for v5.4-rc2

Commit 6dc280ebeed2 ("coda: remove uapi/linux/coda_psdev.h") removed a header in question. Some more build errors were fixed. Add more headers into the test coverage. Signed-off-by: Masahiro Yamada --- Changes in v2: - remove linux/coda_psdev.h as well usr/include/Makefile | 10 --

RE: [PATCH 0/2] peci: aspeed: Add AST2600 compatible

Hi Jae Hyun, Thanks for the feedback. For now should I use GitHub pull-request to submit the patches of PECI-related change to OpenBMC dev-5.3 tree only? Regards, Chiawei * Email Confidentiality Notice DISCLAIMER: This message (and any attachments) may contain

Re: [PATCH] scsi: ch: add include guard to chio.h

Hi, On Mon, Jul 29, 2019 at 1:47 AM Masahiro Yamada wrote: > > Add a header include guard just in case. > > Signed-off-by: Masahiro Yamada > --- Ping? > include/uapi/linux/chio.h | 11 --- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/include/uapi/linux/chio.h

Re: [PATCH] kasan: fix the missing underflow in memmove and memcpy with CONFIG_KASAN_GENERIC=y

On Wed, 2019-10-02 at 15:57 +0200, Dmitry Vyukov wrote: > On Wed, Oct 2, 2019 at 2:15 PM Walter Wu wrote: > > > > On Mon, 2019-09-30 at 12:36 +0800, Walter Wu wrote: > > > On Fri, 2019-09-27 at 21:41 +0200, Dmitry Vyukov wrote: > > > > On Fri, Sep 27, 2019 at 4:22 PM Walter Wu > > > > wrote: >

Re: [PATCH] compiler: enable CONFIG_OPTIMIZE_INLINING forcibly

On Thu, Oct 3, 2019 at 5:46 AM Linus Torvalds wrote: > > On Wed, Oct 2, 2019 at 5:56 AM Geert Uytterhoeven > wrote: > > > > > > > > Then use the C preprocessor to force the inlining. I'm sorry it's not > > > as pretty as static inline functions. > > > > Which makes us lose the baby^H^H^H^Htype

Re: [PATCH] Make SPLIT_RSS_COUNTING configurable

On Wed, Oct 2, 2019 at 6:56 PM Qian Cai wrote: > > On Oct 2, 2019, at 4:29 PM, Daniel Colascione wrote: > > > > Adding the correct linux-mm address. > > > > > >> On Wed, Oct 2, 2019 at 1:25 PM Daniel Colascione wrote: > >> > >> Using the new config option, users can disable SPLIT_RSS_COUNTING

Re: [PATCH 5/6] arm64: tegra: Add XUSB and pad controller on Tegra194

On 10/2/19 6:11 PM, Thierry Reding wrote: > On Wed, Oct 02, 2019 at 04:00:50PM +0800, JC Kuo wrote: >> Adds the XUSB pad and XUSB controllers on Tegra194. >> >> Signed-off-by: JC Kuo >> --- >> arch/arm64/boot/dts/nvidia/tegra194.dtsi | 130 +++ >> 1 file changed, 130

Re: [PATCH 5/6] arm64: tegra: Add XUSB and pad controller on Tegra194

On 10/2/19 6:10 PM, Thierry Reding wrote: > On Wed, Oct 02, 2019 at 04:00:50PM +0800, JC Kuo wrote: >> Adds the XUSB pad and XUSB controllers on Tegra194. >> >> Signed-off-by: JC Kuo >> --- >> arch/arm64/boot/dts/nvidia/tegra194.dtsi | 130 +++ >> 1 file changed, 130

Re: [PATCH 3/6] phy: tegra: xusb: Add Tegra194 support

On 10/2/19 6:02 PM, Thierry Reding wrote: > On Wed, Oct 02, 2019 at 04:00:48PM +0800, JC Kuo wrote: >> Add support for the XUSB pad controller found on Tegra194 SoCs. It is >> mostly similar to the same IP found on Tegra186, but the number of >> pads exposed differs, as do the programming

Re: [PATCH] Make SPLIT_RSS_COUNTING configurable

> On Oct 2, 2019, at 4:29 PM, Daniel Colascione wrote: > > Adding the correct linux-mm address. > > >> On Wed, Oct 2, 2019 at 1:25 PM Daniel Colascione wrote: >> >> Using the new config option, users can disable SPLIT_RSS_COUNTING to >> get increased accuracy in user-visible mm counters.

Re: [PATCH 4/6] dt-bindings: phy: tegra: Add Tegra194 support

Thanks Thierry. I will fix the typo in the next revision. On 10/2/19 5:44 PM, Thierry Reding wrote: > On Wed, Oct 02, 2019 at 04:00:49PM +0800, JC Kuo wrote: >> Extend the bindings to cover the set of features found in Tegra194. >> Note that, technically, there are four more supplies connected to

Re: [PATCH] kheaders: making headers archive reproducible

Hi Dmitry, (+CC Ben Hutchings, who might be interested) On Sun, Sep 22, 2019 at 10:38 PM Dmitry Goldin wrote: > > From: Dmitry Goldin > > In commit 43d8ce9d65a5 ("Provide in-kernel headers to make > extending kernel easier") a new mechanism was introduced, for kernels > >=5.2, which embeds

[PATCH tip/core/rcu 7/9] rcutorture: Make in-kernel-loop testing more brutal

From: "Paul E. McKenney" The rcu_torture_fwd_prog_nr() tests the ability of RCU to tolerate in-kernel busy loops. It invokes rcu_torture_fwd_prog_cond_resched() within its delay loop, which, in PREEMPT && NO_HZ_FULL kernels results in the occasional direct call to schedule(). Now, this direct

[PATCH tip/core/rcu 3/9] rcutorture: Remove CONFIG_HOTPLUG_CPU=n from scenarios

From: "Paul E. McKenney" A number of mainstream CPU families are no longer capable of building kernels having CONFIG_SMP=y and CONFIG_HOTPLUG_CPU=n, so this commit removes this combination from the rcutorture scenarios having it. People wishing to try out this combination may still do so using

[PATCH tip/core/rcu 1/9] rcu: Remove unused function rcutorture_record_progress()

From: Ethan Hansen <1ethanhan...@gmail.com> The function rcutorture_record_progress() is declared in rcu.h, but is never used. This commit therefore removes rcutorture_record_progress() to clean code. Signed-off-by: Ethan Hansen <1ethanhan...@gmail.com> Signed-off-by: Paul E. McKenney ---

[PATCH tip/core/rcu 5/9] rcu: Remove unused variable rcu_perf_writer_state

From: Ethan Hansen <1ethanhan...@gmail.com> The variable rcu_perf_writer_state is declared and initialized, but is never actually referenced. Remove it to clean code. Signed-off-by: Ethan Hansen <1ethanhan...@gmail.com> [ ethansen: Also removed unused macros assigned to that variable. ]

[PATCH tip/core/rcu 2/9] locktorture: Replace strncmp() with str_has_prefix()

From: Chuhong Yuan The strncmp() function is error-prone because it is easy to get the length wrong, especially if the string is subject to change, especially given the need to account for the terminating nul byte. This commit therefore substitutes the newly introduced str_has_prefix(), which

[PATCH tip/core/rcu 9/9] rcu: Suppress levelspread uninitialized messages

From: "Paul E. McKenney" New tools bring new warnings, and with v5.3 comes: kernel/rcu/srcutree.c: warning: 'levelspread[]' may be used uninitialized in this function [-Wuninitialized]: => 121:34 This commit suppresses this warning by initializing the full array to INT_MIN, which will result

[PATCH tip/core/rcu 0/9] Torture-test updates

Hello! This series provides torture-test updates. 1. Remove unused function rcutorture_record_progress(), courtesy of Ethan Hansen. 2. Replace strncmp() with str_has_prefix(), courtesy of Chuhong Yuan. 3. Remove CONFIG_HOTPLUG_CPU=n from scenarios. 4. Emulate

[PATCH tip/core/rcu 8/9] locking: locktorture: Do not include rwlock.h directly

From: "Wolfgang M. Reimer" Including rwlock.h directly will cause kernel builds to fail if CONFIG_PREEMPT_RT is defined. The correct header file (rwlock_rt.h OR rwlock.h) will be included by spinlock.h which is included by locktorture.c anyway. Remove the include of linux/rwlock.h.

[PATCH tip/core/rcu 4/9] rcutorture: Emulate dyntick aspect of userspace nohz_full sojourn

From: "Paul E. McKenney" During an actual call_rcu() flood, there would be frequent trips to userspace (in-kernel call_rcu() floods must be otherwise housebroken). Userspace execution on nohz_full CPUs implies an RCU dyntick idle/not-idle transition pair, so this commit adds emulation of that

[PATCH tip/core/rcu 6/9] rcutorture: Separate warnings for each failure type

From: "Paul E. McKenney" Currently, each of six different types of failure triggers a single WARN_ON_ONCE(), and it is then necessary to stare at the rcu_torture_stats(), Reader Pipe, and Reader Batch lines looking for inappropriately non-zero values. This can be annoying and error-prone, so

[PATCH tip/core/rcu 5/9] fs/afs: Replace rcu_swap_protected() with rcu_replace()

From: "Paul E. McKenney" This commit replaces the use of rcu_swap_protected() with the more intuitively appealing rcu_replace() as a step towards removing rcu_swap_protected(). Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=z7-ggtm6wcvtyytxza1+bhqta4gg...@mail.gmail.com/ Reported-by:

[PATCH tip/core/rcu 9/9] net/sched: Replace rcu_swap_protected() with rcu_replace()

From: "Paul E. McKenney" This commit replaces the use of rcu_swap_protected() with the more intuitively appealing rcu_replace() as a step towards removing rcu_swap_protected(). Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=z7-ggtm6wcvtyytxza1+bhqta4gg...@mail.gmail.com/ Reported-by:

[PATCH tip/core/rcu 1/9] rcu: Upgrade rcu_swap_protected() to rcu_replace()

From: "Paul E. McKenney" Although the rcu_swap_protected() macro follows the example of swap(), the interactions with RCU make its update of its argument somewhat counter-intuitive. This commit therefore introduces an rcu_replace() that returns the old value of the RCU pointer instead of doing

[PATCH tip/core/rcu 4/9] drivers/scsi: Replace rcu_swap_protected() with rcu_replace()

From: "Paul E. McKenney" This commit replaces the use of rcu_swap_protected() with the more intuitively appealing rcu_replace() as a step towards removing rcu_swap_protected(). Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=z7-ggtm6wcvtyytxza1+bhqta4gg...@mail.gmail.com/ Reported-by:

[PATCH tip/core/rcu 2/9] x86/kvm/pmu: Replace rcu_swap_protected() with rcu_replace()

From: "Paul E. McKenney" This commit replaces the use of rcu_swap_protected() with the more intuitively appealing rcu_replace() as a step towards removing rcu_swap_protected(). Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=z7-ggtm6wcvtyytxza1+bhqta4gg...@mail.gmail.com/ Reported-by:

[PATCH tip/core/rcu 6/9] bpf/cgroup: Replace rcu_swap_protected() with rcu_replace()

From: "Paul E. McKenney" This commit replaces the use of rcu_swap_protected() with the more intuitively appealing rcu_replace() as a step towards removing rcu_swap_protected(). Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=z7-ggtm6wcvtyytxza1+bhqta4gg...@mail.gmail.com/ Reported-by:

[PATCH tip/core/rcu 7/9] net/core: Replace rcu_swap_protected() with rcu_replace()

From: "Paul E. McKenney" This commit replaces the use of rcu_swap_protected() with the more intuitively appealing rcu_replace() as a step towards removing rcu_swap_protected(). Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=z7-ggtm6wcvtyytxza1+bhqta4gg...@mail.gmail.com/ Reported-by:

[PATCH tip/core/rcu 8/9] net/netfilter: Replace rcu_swap_protected() with rcu_replace()

From: "Paul E. McKenney" This commit replaces the use of rcu_swap_protected() with the more intuitively appealing rcu_replace() as a step towards removing rcu_swap_protected(). Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=z7-ggtm6wcvtyytxza1+bhqta4gg...@mail.gmail.com/ Reported-by:

[PATCH tip/core/rcu 3/9] drivers/gpu: Replace rcu_swap_protected() with rcu_replace()

From: "Paul E. McKenney" This commit replaces the use of rcu_swap_protected() with the more intuitively appealing rcu_replace() as a step towards removing rcu_swap_protected(). Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=z7-ggtm6wcvtyytxza1+bhqta4gg...@mail.gmail.com/ Reported-by:

[PATCH tip/core/rcu 0/9] Replace rcu_swap_protected() for v5.5

Hello! This series replaces uses of rcu_swap_protected() with rcu_replace(). A later patch will remove rcu_swap_protected(). 1. Upgrade rcu_swap_protected() to rcu_replace(). 2-9.Replace calls to rcu_swap_protected() with rcu_replace().

[PATCH tip/core/rcu 11/12] rcu: Confine ->core_needs_qs accesses to the corresponding CPU

From: "Paul E. McKenney" Commit 671a63517cf9 ("rcu: Avoid unnecessary softirq when system is idle") fixed a bug that could result in an indefinite number of unnecessary invocations of the RCU_SOFTIRQ handler at the trailing edge of a scheduler-clock interrupt. However, the fix introduced

[PATCH tip/core/rcu 03/12] rcu: Force on tick when invoking lots of callbacks

From: "Paul E. McKenney" Callback invocation can run for a significant time period, and within CONFIG_NO_HZ_FULL=y kernels, this period will be devoid of scheduler-clock interrupts. In-kernel execution without such interrupts can cause all manner of malfunction, with RCU CPU stall warnings

[PATCH tip/core/rcu 10/12] rcu: Reset CPU hints when reporting a quiescent state

From: "Joel Fernandes (Google)" In some cases, tracing shows that need_heavy_qs is still set even though urgent_qs was cleared upon reporting of a quiescent state. One such case is when the softirq reports that a CPU has passed quiescent state. Commit 671a63517cf9 ("rcu: Avoid unnecessary

[PATCH tip/core/rcu 07/12] stop_machine: Use {READ,WRITE)_ONCE() for multi_cpu_stop() ->state

From: "Paul E. McKenney" The multi_stop_data structure's ->state field is updated and read concurrently, so this commit replaces the current C-language accesses with READ_ONCE() and WRITE_ONCE(). Signed-off-by: Paul E. McKenney --- kernel/stop_machine.c | 6 +++--- 1 file changed, 3

[PATCH tip/core/rcu 01/12] nohz: Add TICK_DEP_BIT_RCU

From: Frederic Weisbecker If a nohz_full CPU is looping in the kernel, the scheduling-clock tick might nevertheless remain disabled. In !PREEMPT kernels, this can prevent RCU's attempts to enlist the aid of that CPU's executions of cond_resched(), which can in turn result in an arbitrarily

[PATCH tip/core/rcu 06/12] rcu: Make CPU-hotplug removal operations enable tick

From: "Paul E. McKenney" CPU-hotplug removal operations run the multi_cpu_stop() function, which relies on the scheduler to gain control from whatever is running on the various online CPUs, including any nohz_full CPUs running long loops in kernel-mode code. Lack of the scheduler-clock

[PATCH tip/core/rcu 02/12] time: Export tick start/stop functions for rcutorture

From: "Paul E. McKenney" It turns out that rcutorture needs to ensure that the scheduling-clock interrupt is enabled in CONFIG_NO_HZ_FULL kernels before starting on CPU-bound in-kernel processing. This commit therefore exports tick_nohz_dep_set_task(), tick_nohz_dep_clear_task(), and

[PATCH tip/core/rcu 09/12] rcu: Force nohz_full tick on upon irq enter instead of exit

From: "Paul E. McKenney" There is interrupt-exit code that forces on the tick for nohz_full CPUs failing to respond to the current grace period in a timely fashion. However, this code must compare ->dynticks_nmi_nesting to the value 2 in the interrupt-exit fastpath. This commit therefore moves

[PATCH tip/core/rcu 04/12] rcutorture: Force on tick for readers and callback flooders

From: "Paul E. McKenney" Readers and callback flooders in the rcutorture stress-test suite run for extended time periods by design. They do take pains to relinquish the CPU from time to time, but in some cases this relies on the scheduler being active, which in turn relies on the

[PATCH tip/core/rcu 12/12] rcu: Make kernel-mode nohz_full CPUs invoke the RCU core processing

From: "Paul E. McKenney" If a nohz_full CPU is idle or executing in userspace, it makes good sense to keep it out of RCU core processing. After all, the RCU grace-period kthread can see its quiescent states and all of its callbacks are offloaded, so there is nothing for RCU core processing to

[PATCH tip/core/rcu 05/12] stop_machine: EXP Provide RCU quiescent state in multi_cpu_stop()

From: "Paul E. McKenney" When multi_cpu_stop() loops waiting for other tasks, it can trigger an RCU CPU stall warning. This can be misleading because what is instead needed is information on whatever task is blocking multi_cpu_stop(). This commit therefore inserts an RCU quiescent state into

[PATCH tip/core/rcu 08/12] rcu: Force tick on for nohz_full CPUs not reaching quiescent states

From: "Paul E. McKenney" CPUs running for long time periods in the kernel in nohz_full mode might leave the scheduling-clock interrupt disabled for then full duration of their in-kernel execution. This can (among other things) delay grace periods. This commit therefore forces the tick back on

[PATCH tip/core/rcu 0/12] NO_HZ fixes for v5.5

Hello! This series contains various fixes for NO_HZ and NO_HZ_FULL problems, including re-enabling the tick during long-term kernel-mode execution. 1. Add TICK_DEP_BIT_RCU (which allows RCU-specific tick re-enabling), courtesy of Frederic Weisbecker. 2. Export tick start/stop

[PATCH tip/core/rcu 3/8] workqueue: Convert for_each_wq to use built-in list check

From: "Joel Fernandes (Google)" Because list_for_each_entry_rcu() can now check for holding a lock as well as for being in an RCU read-side critical section, this commit replaces the workqueue_sysfs_unregister() function's use of assert_rcu_or_wq_mutex() and list_for_each_entry_rcu() with

[PATCH tip/core/rcu 6/8] rcu: Update descriptions for rcu_nocb_wake tracepoint

From: "Paul E. McKenney" Signed-off-by: Paul E. McKenney --- include/trace/events/rcu.h | 35 +-- 1 file changed, 21 insertions(+), 14 deletions(-) diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h index afa8985..4609f2e 100644 ---

[PATCH tip/core/rcu 5/8] rcu: Remove obsolete descriptions for rcu_barrier tracepoint

From: "Paul E. McKenney" Signed-off-by: Paul E. McKenney --- include/trace/events/rcu.h | 2 -- 1 file changed, 2 deletions(-) diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h index 694bd04..afa8985 100644 --- a/include/trace/events/rcu.h +++ b/include/trace/events/rcu.h

[PATCH tip/core/rcu 4/8] rcu: Ensure that ->rcu_urgent_qs is set before resched IPI

From: "Joel Fernandes (Google)" The RCU-specific resched_cpu() function sends a resched IPI to the specified CPU, which can be used to force the tick on for a given nohz_full CPU. This is needed when this nohz_full CPU is looping in the kernel while blocking the current grace period. However,

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