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2013-05-14powerpc: select HAVE_CONTEXT_TRACKING for pSeriesLi Zhong1-0/+1
Start context tracking support from pSeries. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Use the new schedule_user API on userspace preemptionLi Zhong2-1/+12
This patch corresponds to [PATCH] x86: Use the new schedule_user API on userspace preemption commit 0430499ce9d78691f3985962021b16bf8f8a8048 Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Exit user context on notify resumeLi Zhong1-0/+5
This patch allows RCU usage in do_notify_resume, e.g. signal handling. It corresponds to [PATCH] x86: Exit RCU extended QS on notify resume commit edf55fda35c7dc7f2d9241c3abaddaf759b457c6 Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Exception hooks for context tracking subsystemLi Zhong3-45/+112
This is the exception hooks for context tracking subsystem, including data access, program check, single step, instruction breakpoint, machine check, alignment, fp unavailable, altivec assist, unknown exception, whose handlers might use RCU. This patch corresponds to [PATCH] x86: Exception hooks for userspace RCU extended QS commit 6ba3c97a38803883c2eee489505796cb0a727122 But after the exception handling moved to generic code, and some changes in following two commits: 56dd9470d7c8734f055da2a6bac553caf4a468eb context_tracking: Move exception handling to generic code 6c1e0256fad84a843d915414e4b5973b7443d48d context_tracking: Restore correct previous context state on exception exit it is able for exception hooks to use the generic code above instead of a redundant arch implementation. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Syscall hooks for context tracking subsystemLi Zhong2-2/+10
This is the syscall slow path hooks for context tracking subsystem, corresponding to [PATCH] x86: Syscall hooks for userspace RCU extended QS commit bf5a3c13b939813d28ce26c01425054c740d6731 TIF_MEMDIE is moved to the second 16-bits (with value 17), as it seems there is no asm code using it. TIF_NOHZ is added to _TIF_SYCALL_T_OR_A, so it is better for it to be in the same 16 bits with others in the group, so in the asm code, andi. with this group could work. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc/booke64: Fix kernel hangs at kernel_dbg_excScott Wood2-4/+11
MSR_DE is not cleared on entry to the kernel, and we don't clear it explicitly outside of debug code. If we have MSR_DE set in prime_debug_regs(), and the new thread has events enabled in DBCR0 (e.g. ICMP is set in thread->dbsr0, even though it was cleared in the real DBCR0 when the thread got scheduled out), we'll end up taking a debug exception in the kernel when DBCR0 is loaded. DSRR0 will not point to an exception vector, and the kernel ends up hanging at kernel_dbg_exc. Fix this by always clearing MSR_DE when we load new debug state. Another observed source of kernel_dbg_exc hangs is with the branch taken event. If this event is active, but we take a non-debug trap (e.g. a TLB miss or an asynchronous interrupt) before the next branch. We end up taking a branch-taken debug exception on the initial branch instruction of the exception vector, but because the debug exception is DBSR_BT rather than DBSR_IC we branch to kernel_dbg_exc before even checking the DSRR0 address. Fix this by checking for DBSR_BT as well as DBSR_IC, which is what 32-bit does and what the comments suggest was intended in the 64-bit code as well. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Fix irq_set_affinity() return valuesAlexander Gordeev4-4/+4
Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Provide __bswapdi2David Woodhouse3-1/+24
Some versions of GCC apparently expect this to be provided by libgcc. Updates from Mikey to fix 32 bit version and adding "r" to registers. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc/powernv: Fix starting of secondary CPUs on OPALv2 and v3Benjamin Herrenschmidt1-6/+56
The current code fails to handle kexec on OPALv2. This fixes it and adds code to improve the situation on OPALv3 where we can query the CPU status from the firmware and decide what to do based on that. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc/powernv: Detect OPAL v3 API versionBenjamin Herrenschmidt4-4/+13
Future firmwares will support that new version Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Fix MAX_STACK_TRACE_ENTRIES too low warning againLi Zhong3-4/+1
Saw this warning again, and this time from the ret_from_fork path. It seems we could clear the back chain earlier in copy_thread(), which could cover both path, and also fix potential lockdep usage in schedule_tail(), or exception occurred before we clear the back chain. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Make CONFIG_RTAS_PROC depend on CONFIG_PROC_FSMichael Ellerman1-1/+1
We are getting build errors with CONFIG_PROC_FS=n: arch/powerpc/kernel/rtas_flash.c In function 'rtas_flash_init': 745:33: error: unused variable 'f' [-Werror=unused-variable] But rtas_flash.c should not be built when CONFIG_PROC_FS=n, beacause all it does is provide a /proc interface to the RTAS flash routines. CONFIG_RTAS_FLASH already depends on CONFIG_RTAS_PROC, to indicate that it depends on the RTAS proc support, but CONFIG_RTAS_PROC does not depend on CONFIG_PROC_FS. So fix that. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Bring all threads online prior to migration/hibernationRobert Jennings3-0/+137
This patch brings online all threads which are present but not online prior to migration/hibernation. After migration/hibernation those threads are taken back offline. During migration/hibernation all online CPUs must call H_JOIN, this is required by the hypervisor. Without this patch, threads that are offline (H_CEDE'd) will not be woken to make the H_JOIN call and the OS will be deadlocked (all threads either JOIN'd or CEDE'd). Cc: <stable@kernel.org> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc/rtas_flash: Fix validate_flash buffer overflow issueVasant Hegde1-4/+6
ibm,validate-flash-image RTAS call output buffer contains 150 - 200 bytes of data on latest system. Presently we have output buffer size as 64 bytes and we use sprintf to copy data from RTAS buffer to local buffer. This causes kernel oops (see below call trace). This patch increases local buffer size to 256 and also uses snprintf instead of sprintf to copy data from RTAS buffer. Kernel call trace : ------------------- Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=1024 NUMA pSeries Modules linked in: nfs fscache lockd auth_rpcgss nfs_acl sunrpc fuse loop dm_mod ipv6 ipv6_lib usb_storage ehea(X) sr_mod qlge ses cdrom enclosure st be2net sg ext3 jbd mbcache usbhid hid ohci_hcd ehci_hcd usbcore qla2xxx usb_common sd_mod crc_t10dif scsi_dh_hp_sw scsi_dh_rdac scsi_dh_alua scsi_dh_emc scsi_dh lpfc scsi_transport_fc scsi_tgt ipr(X) libata scsi_mod Supported: Yes NIP: 4520323031333130 LR: 4520323031333130 CTR: 0000000000000000 REGS: c0000001b91779b0 TRAP: 0400 Tainted: G X (3.0.13-0.27-ppc64) MSR: 8000000040009032 <EE,ME,IR,DR> CR: 44022488 XER: 20000018 TASK = c0000001bca1aba0[4736] 'cat' THREAD: c0000001b9174000 CPU: 36 GPR00: 4520323031333130 c0000001b9177c30 c000000000f87c98 000000000000009b GPR04: c0000001b9177c4a 000000000000000b 3520323031333130 2032303133313031 GPR08: 3133313031350a4d 000000000000009b 0000000000000000 c0000000003664a4 GPR12: 0000000022022448 c000000003ee6c00 0000000000000002 00000000100e8a90 GPR16: 00000000100cb9d8 0000000010093370 000000001001d310 0000000000000000 GPR20: 0000000000008000 00000000100fae60 000000000000005e 0000000000000000 GPR24: 0000000010129350 46573738302e3030 2046573738302e30 300a4d4720323031 GPR28: 333130313520554e 4b4e4f574e0a4d47 2032303133313031 3520323031333130 NIP [4520323031333130] 0x4520323031333130 LR [4520323031333130] 0x4520323031333130 Call Trace: [c0000001b9177c30] [4520323031333130] 0x4520323031333130 (unreliable) Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc/kexec: Fix kexec when using VMX optimised memcpyAnton Blanchard1-0/+4
commit b3f271e86e5a (powerpc: POWER7 optimised memcpy using VMX and enhanced prefetch) uses VMX when it is safe to do so (ie not in interrupt). It also looks at the task struct to decide if we have to save the current tasks' VMX state. kexec calls memcpy() at a point where the task struct may have been overwritten by the new kexec segments. If it has been overwritten then when memcpy -> enable_altivec looks up current->thread.regs->msr we get a cryptic oops or lockup. I also notice we aren't initialising thread_info->cpu, which means smp_processor_id is broken. Fix that too. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@vger.kernel.org> # 3.6+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Fix build errors STRICT_MM_TYPECHECKSAneesh Kumar K.V3-5/+5
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc/mm: Use the correct mask value when looking at pgtable addressAneesh Kumar K.V1-1/+1
Our pgtable are 2*sizeof(pte_t)*PTRS_PER_PTE which is PTE_FRAG_SIZE. Instead of depending on frag size, mask with PMD_MASKED_BITS. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-10powerpc: hard_irq_disable(): Call trace_hardirqs_off after disablingScott Wood1-2/+3
lockdep.c has this: /* * So we're supposed to get called after you mask local IRQs, * but for some reason the hardware doesn't quite think you did * a proper job. */ if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) return; Since irqs_disabled() is based on soft_enabled(), that (not just the hard EE bit) needs to be 0 before we call trace_hardirqs_off. Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-05-10powerpc/powernv: Improve kexec reliabilityBenjamin Herrenschmidt7-0/+56
We add a machine_shutdown hook that frees the OPAL interrupts (so they get masked at the source and don't fire while kexec'ing) and which triggers an IODA reset on all the PCIe host bridges which will have the effect of blocking all DMAs and subsequent PCIs interrupts. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-08powerpc/powernv: Properly drop characters if console is closedBenjamin Herrenschmidt1-0/+7
If the firmware returns an error such as "closed" (or hardware error), we should drop characters. Currently we only do that when a firmware compatible with OPAL v2 APIs is detected, in the code that calls opal_console_write_buffer_space(), which didn't exist with OPAL v1 (or didn't work). However, when enabling early debug consoles, the flag indicating that v2 is supported isn't set yet, causing us, in case of errors or closed console, to spin forever. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-08powerpc: Add an in memory udbg consoleAlistair Popple5-0/+134
This patch adds a new udbg early debug console which utilises statically defined input and output buffers stored within the kernel BSS. It is primarily designed to assist with bring up of new hardware which may not have a working console but which has a method of reading/writing kernel memory. This version incorporates comments made by Ben H (thanks!). Changes from v1: - Add memory barriers. - Ensure updating of read/write positions is atomic. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-07powerpc: Make hard_irq_disable() do the right thing vs. irq tracingBenjamin Herrenschmidt1-9/+7
If hard_irq_disable() is called while interrupts are already soft-disabled (which is the most common case) all is already well. However you can (and in some cases want) to call it while everything is enabled (to make sure you don't get a lazy even, for example before entry into KVM guests) and in this case we need to inform the irq tracer that the irqs are going off. We have to change the inline into a macro to avoid an include circular dependency hell hole. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/topology: Fix spurr attribute permissionBenjamin Herrenschmidt1-1/+1
We are registering the attribute with permission 0600 but it doesn't have a store callback, which causes WARN_ON's during boot. Fix the permission. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/pci: Support per-aperture memory offsetBenjamin Herrenschmidt10-104/+54
The PCI core supports an offset per aperture nowadays but our arch code still has a single offset per host bridge representing the difference betwen CPU memory addresses and PCI MMIO addresses. This is a problem as new machines and hypervisor versions are coming out where the 64-bit windows will have a different offset (basically mapped 1:1) from the 32-bit windows. This fixes it by using separate offsets. In the long run, we probably want to get rid of that intermediary struct pci_controller and have those directly stored into the pci_host_bridge as they are parsed but this will be a more invasive change. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/cell/iommu: Improve error message for missing nodeBenjamin Herrenschmidt1-1/+1
Some devices don't have a correct node ID and thus can't be attached to an iommu. The message displayed by the iommu code isn't very useful if you don't have a device-tree node as it tries to print the device-tree path but not the struct device name. Improve this by printing the device name as well. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/cell/spufs: Fix status attribute permissionBenjamin Herrenschmidt1-1/+1
We are registering the attribute with permission 0644 but it doesn't have a store callback, which causes WARN_ON's during boot. Fix the permission. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06irqdomain: Allow quiet failure modeBenjamin Herrenschmidt2-6/+28
Some interrupt controllers refuse to map interrupts marked as "protected" by firwmare. Since we try to map everyting in the device-tree on some platforms, we end up with a lot of nasty WARN's in the boot log for what is a normal situation on those machines. This defines a specific return code (-EPERM) from the host map() callback which cause irqdomain to fail silently. MPIC is updated to return this when hitting a protected source printing only a single line message for diagnostic purposes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/pnv: Fix "compatible" property for P8 PHBBenjamin Herrenschmidt1-1/+1
The property should be "ibm,power8-pciex", not "ibm,p8-pciex". The latter was changed in FW because it was inconsistent with the rest of the nodes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/pci: Don't add bogus empty resources to PHBsBenjamin Herrenschmidt1-14/+16
When converting to use the new pci_add_resource_offset() we didn't properly account for empty resources (0 flags) and add those bogons to the PHBs. The result is some annoying messages in the log. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/powerpnv: Properly handle failure starting CPUsBenjamin Herrenschmidt1-1/+3
If OPAL returns an error, propagate it upward rather than spinning seconds waiting for a CPU that will never show up Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/cputable: Advertise support for ISEL/HTM/DSCR/TAR on POWER8Nishanth Aravamudan1-0/+5
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/cputable: Advertise ISEL support on appropriate embedded processorsNishanth Aravamudan1-0/+5
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/cputable: Advertise DSCR support on P7/P7+Nishanth Aravamudan1-0/+4
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/cputable: Reserve bits in HWCAP2 for new featuresNishanth Aravamudan2-0/+11
Also, make HTM's presence dependent on the .config option. Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/pseries: Perform proper max_bus_speed detectionKleber Sacilotto de Souza5-0/+70
On pseries machines the detection for max_bus_speed should be done through an OpenFirmware property. This patch adds a function to perform this detection and a hook to perform dynamic adding of the function only for pseries. This is done by overwriting the weak pcibios_root_bridge_prepare function which is called by pci_create_root_bus(). From: Lucas Kannebley Tavares <lucaskt@linux.vnet.ibm.com> Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/pseries: Force 32 bit MSIs for devices that require itBrian King2-3/+20
The following patch implements a new PAPR change which allows the OS to force the use of 32 bit MSIs, regardless of what the PCI capabilities indicate. This is required for some devices that advertise support for 64 bit MSIs but don't actually support them. Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/tm: Fix null pointer deference in flush_hash_pageMichael Neuling1-0/+1
Make sure that current->thread.reg exists before we deference it in flush_hash_page. Signed-off-by: Michael Neuling <mikey@neuling.org> Reported-by: John J Miller <millerjo@us.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc/powernv: Defer OPAL exception handler registrationJeremy Kerr1-2/+13
Currently, the OPAL exception vectors are registered before the feature fixups are processed. This means that the now-firmware-owned vectors will likely be overwritten by the kernel. This change moves the exception registration code to an early initcall, rather than at machine_init time. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-06powerpc: Emulate non privileged DSCR read and writeAnton Blanchard2-2/+12
POWER8 allows read and write of the DSCR in userspace. We added kernel emulation so applications could always use the instructions regardless of the CPU type. Unfortunately there are two SPRs for the DSCR and we only added emulation for the privileged one. Add code to match the non privileged one. A simple test was created to verify the fix: http://ozlabs.org/~anton/junkcode/user_dscr_test.c Without the patch we get a SIGILL and it passes with the patch. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-05Merge tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds110-2270/+8522
Pull kvm updates from Gleb Natapov: "Highlights of the updates are: general: - new emulated device API - legacy device assignment is now optional - irqfd interface is more generic and can be shared between arches x86: - VMCS shadow support and other nested VMX improvements - APIC virtualization and Posted Interrupt hardware support - Optimize mmio spte zapping ppc: - BookE: in-kernel MPIC emulation with irqfd support - Book3S: in-kernel XICS emulation (incomplete) - Book3S: HV: migration fixes - BookE: more debug support preparation - BookE: e6500 support ARM: - reworking of Hyp idmaps s390: - ioeventfd for virtio-ccw And many other bug fixes, cleanups and improvements" * tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits) kvm: Add compat_ioctl for device control API KVM: x86: Account for failing enable_irq_window for NMI window request KVM: PPC: Book3S: Add API for in-kernel XICS emulation kvm/ppc/mpic: fix missing unlock in set_base_addr() kvm/ppc: Hold srcu lock when calling kvm_io_bus_read/write kvm/ppc/mpic: remove users kvm/ppc/mpic: fix mmio region lists when multiple guests used kvm/ppc/mpic: remove default routes from documentation kvm: KVM_CAP_IOMMU only available with device assignment ARM: KVM: iterate over all CPUs for CPU compatibility check KVM: ARM: Fix spelling in error message ARM: KVM: define KVM_ARM_MAX_VCPUS unconditionally KVM: ARM: Fix API documentation for ONE_REG encoding ARM: KVM: promote vfp_host pointer to generic host cpu context ARM: KVM: add architecture specific hook for capabilities ARM: KVM: perform HYP initilization for hotplugged CPUs ARM: KVM: switch to a dual-step HYP init code ARM: KVM: rework HYP page table freeing ARM: KVM: enforce maximum size for identity mapped code ARM: KVM: move to a KVM provided HYP idmap ...
2013-05-05Give the OID registry file module info to avoid kernel taintingDavid Howells1-0/+5
Give the OID registry file module information so that it doesn't taint the kernel when compiled as a module and loaded. Reported-by: Dros Adamson <Weston.Adamson@netapp.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Trond Myklebust <Trond.Myklebust@netapp.com> cc: stable@vger.kernel.org cc: linux-nfs@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-05Merge branch 'timers-nohz-for-linus' of ↵Linus Torvalds31-119/+990
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull 'full dynticks' support from Ingo Molnar: "This tree from Frederic Weisbecker adds a new, (exciting! :-) core kernel feature to the timer and scheduler subsystems: 'full dynticks', or CONFIG_NO_HZ_FULL=y. This feature extends the nohz variable-size timer tick feature from idle to busy CPUs (running at most one task) as well, potentially reducing the number of timer interrupts significantly. This feature got motivated by real-time folks and the -rt tree, but the general utility and motivation of full-dynticks runs wider than that: - HPC workloads get faster: CPUs running a single task should be able to utilize a maximum amount of CPU power. A periodic timer tick at HZ=1000 can cause a constant overhead of up to 1.0%. This feature removes that overhead - and speeds up the system by 0.5%-1.0% on typical distro configs even on modern systems. - Real-time workload latency reduction: CPUs running critical tasks should experience as little jitter as possible. The last remaining source of kernel-related jitter was the periodic timer tick. - A single task executing on a CPU is a pretty common situation, especially with an increasing number of cores/CPUs, so this feature helps desktop and mobile workloads as well. The cost of the feature is mainly related to increased timer reprogramming overhead when a CPU switches its tick period, and thus slightly longer to-idle and from-idle latency. Configuration-wise a third mode of operation is added to the existing two NOHZ kconfig modes: - CONFIG_HZ_PERIODIC: [formerly !CONFIG_NO_HZ], now explicitly named as a config option. This is the traditional Linux periodic tick design: there's a HZ tick going on all the time, regardless of whether a CPU is idle or not. - CONFIG_NO_HZ_IDLE: [formerly CONFIG_NO_HZ=y], this turns off the periodic tick when a CPU enters idle mode. - CONFIG_NO_HZ_FULL: this new mode, in addition to turning off the tick when a CPU is idle, also slows the tick down to 1 Hz (one timer interrupt per second) when only a single task is running on a CPU. The .config behavior is compatible: existing !CONFIG_NO_HZ and CONFIG_NO_HZ=y settings get translated to the new values, without the user having to configure anything. CONFIG_NO_HZ_FULL is turned off by default. This feature is based on a lot of infrastructure work that has been steadily going upstream in the last 2-3 cycles: related RCU support and non-periodic cputime support in particular is upstream already. This tree adds the final pieces and activates the feature. The pull request is marked RFC because: - it's marked 64-bit only at the moment - the 32-bit support patch is small but did not get ready in time. - it has a number of fresh commits that came in after the merge window. The overwhelming majority of commits are from before the merge window, but still some aspects of the tree are fresh and so I marked it RFC. - it's a pretty wide-reaching feature with lots of effects - and while the components have been in testing for some time, the full combination is still not very widely used. That it's default-off should reduce its regression abilities and obviously there are no known regressions with CONFIG_NO_HZ_FULL=y enabled either. - the feature is not completely idempotent: there is no 100% equivalent replacement for a periodic scheduler/timer tick. In particular there's ongoing work to map out and reduce its effects on scheduler load-balancing and statistics. This should not impact correctness though, there are no known regressions related to this feature at this point. - it's a pretty ambitious feature that with time will likely be enabled by most Linux distros, and we'd like you to make input on its design/implementation, if you dislike some aspect we missed. Without flaming us to crisp! :-) Future plans: - there's ongoing work to reduce 1Hz to 0Hz, to essentially shut off the periodic tick altogether when there's a single busy task on a CPU. We'd first like 1 Hz to be exposed more widely before we go for the 0 Hz target though. - once we reach 0 Hz we can remove the periodic tick assumption from nr_running>=2 as well, by essentially interrupting busy tasks only as frequently as the sched_latency constraints require us to do - once every 4-40 msecs, depending on nr_running. I am personally leaning towards biting the bullet and doing this in v3.10, like the -rt tree this effort has been going on for too long - but the final word is up to you as usual. More technical details can be found in Documentation/timers/NO_HZ.txt" * 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits) sched: Keep at least 1 tick per second for active dynticks tasks rcu: Fix full dynticks' dependency on wide RCU nocb mode nohz: Protect smp_processor_id() in tick_nohz_task_switch() nohz_full: Add documentation. cputime_nsecs: use math64.h for nsec resolution conversion helpers nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config nohz: Reduce overhead under high-freq idling patterns nohz: Remove full dynticks' superfluous dependency on RCU tree nohz: Fix unavailable tick_stop tracepoint in dynticks idle nohz: Add basic tracing nohz: Select wide RCU nocb for full dynticks nohz: Disable the tick when irq resume in full dynticks CPU nohz: Re-evaluate the tick for the new task after a context switch nohz: Prepare to stop the tick on irq exit nohz: Implement full dynticks kick nohz: Re-evaluate the tick from the scheduler IPI sched: New helper to prevent from stopping the tick in full dynticks sched: Kick full dynticks CPU that have more than one task enqueued. perf: New helper to prevent full dynticks CPUs from stopping tick perf: Kick full dynticks CPU if events rotation is needed ...
2013-05-05Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds5-26/+51
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc fixes plus a small hw-enablement patch for Intel IB model 58 uncore events" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/lbr: Demand proper privileges for PERF_SAMPLE_BRANCH_KERNEL perf/x86/intel/lbr: Fix LBR filter perf/x86: Blacklist all MEM_*_RETIRED events for Ivy Bridge perf: Fix vmalloc ring buffer pages handling perf/x86/intel: Fix unintended variable name reuse perf/x86/intel: Add support for IvyBridge model 58 Uncore perf/x86/intel: Fix typo in perf_event_intel_uncore.c x86: Eliminate irq_mis_count counted in arch_irq_stat
2013-05-05Merge tag 'modules-next-for-linus' of ↵Linus Torvalds23-139/+201
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull mudule updates from Rusty Russell: "We get rid of the general module prefix confusion with a binary config option, fix a remove/insert race which Never Happens, and (my favorite) handle the case when we have too many modules for a single commandline. Seriously, the kernel is full, please go away!" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: modpost: fix unwanted VMLINUX_SYMBOL_STR expansion X.509: Support parse long form of length octets in Authority Key Identifier module: don't unlink the module until we've removed all exposure. kernel: kallsyms: memory override issue, need check destination buffer length MODSIGN: do not send garbage to stderr when enabling modules signature modpost: handle huge numbers of modules. modpost: add -T option to read module names from file/stdin. modpost: minor cleanup. genksyms: pass symbol-prefix instead of arch module: fix symbol versioning with symbol prefixes CONFIG_SYMBOL_PREFIX: cleanup.
2013-05-05Merge branch 'for-linus' of ↵Linus Torvalds33-41/+41
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull single_open() leak fixes from Al Viro: "A bunch of fixes for a moderately common class of bugs: file with single_open() done by its ->open() and seq_release as its ->release(). That leaks; fortunately, it's not _too_ common (either people manage to RTFM that says "When using single_open(), the programmer should use single_release() instead of seq_release() in the file_operations structure to avoid a memory leak", or they just copy a correct instance), but grepping through the tree has caught quite a pile. All of that is, AFAICS, -stable fodder, for as far as the patches apply. I tried to carve it up into reasonably-sized pieces (more or less "comes from the same tree")" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: rcutrace: single_open() leaks gadget: single_open() leaks staging: single_open() leaks megaraid: single_open() leak wireless: single_open() leaks input: single_open() leak rtc: single_open() leaks ds1620: single_open() leak sh: single_open() leaks parisc: single_open() leaks mips: single_open() leaks ia64: single_open() leaks h8300: single_open() leaks cris: single_open() leaks arm: single_open() leaks
2013-05-05Merge branch 'ipc-cleanups'Linus Torvalds1-44/+42
Merge ipc fixes and cleanups from my IPC branch. The ipc locking has always been pretty ugly, and the scalability fixes to some degree made it even less readable. We had two cases of double unlocks in error paths due to this (one rcu read unlock, one semaphore unlock), and this fixes the bugs I found while trying to clean things up a bit so that we are less likely to have more. * ipc-cleanups: ipc: simplify rcu_read_lock() in semctl_nolock() ipc: simplify semtimedop/semctl_main() common error path handling ipc: move sem_obtain_lock() rcu locking into the only caller ipc: fix double sem unlock in semctl error path ipc: move the rcu_read_lock() from sem_lock_and_putref() into callers ipc: sem_putref() does not need the semaphore lock any more ipc: move rcu_read_unlock() out of sem_unlock() and into callers
2013-05-05kvm: Add compat_ioctl for device control APIScott Wood1-0/+3
This API shouldn't have 32/64-bit issues, but VFS assumes it does unless told otherwise. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-05perf/x86/intel/lbr: Demand proper privileges for PERF_SAMPLE_BRANCH_KERNELPeter Zijlstra1-3/+10
We should always have proper privileges when requesting kernel data. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: eranian@google.com Link: http://lkml.kernel.org/r/20130503121256.230745028@chello.nl [ Fix build error reported by fengguang.wu@intel.com, propagate error code back. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/n/tip-v0x9ky3ahzr6nm3c6ilwrili@git.kernel.org
2013-05-05rcutrace: single_open() leaksAl Viro1-4/+4
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-05gadget: single_open() leaksAl Viro2-2/+2
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>