- 25 Jun, 2019 2 commits
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Adrian Hunter authored
Commit f08046cb ("perf thread-stack: Represent jmps to the start of a different symbol") had the side-effect of introducing more stack entries before return from kernel space. When user space is also traced, those entries are popped before entry to user space, but when user space is not traced, they get stuck at the bottom of the stack, making the stack grow progressively larger. Fix by detecting a return-from-kernel branch type, and popping kernel addresses from the stack then. Note, the problem and fix affect the exported Call Graph / Tree but not the callindent option used by "perf script --call-trace". Example: perf-with-kcore record example -e intel_pt//k -- ls perf-with-kcore script example --itrace=bep -s ~/libexec/perf-core/scripts/python/export-to-sqlite.py example.db branches calls ~/libexec/perf-core/scripts/python/exported-sql-viewer.py example.db Menu option: Reports -> Context-Sensitive Call Graph Before: (showing Call Path column only) Call Path
▶ perf ▼ ls ▼ 12111:12111▶ setup_new_exec▶ __task_pid_nr_ns▶ perf_event_pid_type▶ perf_event_comm_output▶ perf_iterate_ctx▶ perf_iterate_sb▶ perf_event_comm▶ __set_task_comm▶ load_elf_binary▶ search_binary_handler▶ __do_execve_file.isra.41▶ __x64_sys_execve▶ do_syscall_64 ▼ entry_SYSCALL_64_after_hwframe ▼ swapgs_restore_regs_and_return_to_usermode ▼ native_iret▶ error_entry▶ do_page_fault ▼ error_exit ▼ retint_user▶ prepare_exit_to_usermode ▼ native_iret▶ error_entry▶ do_page_fault ▼ error_exit ▼ retint_user▶ prepare_exit_to_usermode ▼ native_iret▶ error_entry▶ do_page_fault ▼ error_exit ▼ retint_user▶ prepare_exit_to_usermode▶ native_iret After: (showing Call Path column only) Call Path▶ perf ▼ ls ▼ 12111:12111▶ setup_new_exec▶ __task_pid_nr_ns▶ perf_event_pid_type▶ perf_event_comm_output▶ perf_iterate_ctx▶ perf_iterate_sb▶ perf_event_comm▶ __set_task_comm▶ load_elf_binary▶ search_binary_handler▶ __do_execve_file.isra.41▶ __x64_sys_execve▶ do_syscall_64▶ entry_SYSCALL_64_after_hwframe▶ page_fault ▼ entry_SYSCALL_64 ▼ do_syscall_64▶ __x64_sys_brk▶ __x64_sys_access▶ __x64_sys_openat▶ __x64_sys_newfstat▶ __x64_sys_mmap▶ __x64_sys_close▶ __x64_sys_read▶ __x64_sys_mprotect▶ __x64_sys_arch_prctl▶ __x64_sys_munmap▶ exit_to_usermode_loop▶ __x64_sys_set_tid_address▶ __x64_sys_set_robust_list▶ __x64_sys_rt_sigaction▶ __x64_sys_rt_sigprocmask▶ __x64_sys_prlimit64▶ __x64_sys_statfs▶ __x64_sys_ioctl▶ __x64_sys_getdents64▶ __x64_sys_write▶ __x64_sys_exit_group Committer notes: The first arg to the perf-with-kcore needs to be the same for the 'record' and 'script' lines, otherwise we'll record the perf.data file and kcore_dir/ files in one directory ('example') to then try to use it from the 'bep' directory, fix the instructions above it so that both use 'example'. Signed-off-by:Adrian Hunter <adrian.hunter@intel.com> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@vger.kernel.org Fixes: f08046cb ("perf thread-stack: Represent jmps to the start of a different symbol") Link: http://lkml.kernel.org/r/20190619064429.14940-2-adrian.hunter@intel.comSigned-off-by:
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Numfor Mbiziwo-Tiapo authored
Change the include path so that progress.c can find cache.h since it was previously searching in the wrong directory. Committer notes: $ ls -la tools/perf/ui/../cache.h ls: cannot access 'tools/perf/ui/../cache.h': No such file or directory So it really should include ../../util/cache.h, or plain cache.h, since we have -Iutil in INC_FLAGS in tools/perf/Makefile.config Signed-off-by:
Numfor Mbiziwo-Tiapo <nums@google.com> Cc: Jiri Olsa <jolsa@redhat.com>, Cc: Luke Mujica <lukemujica@google.com>, Cc: Stephane Eranian <eranian@google.com> To: Ian Rogers <irogers@google.com> Link: https://lkml.kernel.org/n/tip-pud8usyutvd2npg2vpsygncz@git.kernel.orgSigned-off-by:
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- 24 Jun, 2019 11 commits
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Ian Rogers authored
Currently perf_rotate_context assumes that if the context's nr_events != nr_active a rotation is necessary for perf event multiplexing. With cgroups, nr_events is the total count of events for all cgroups and nr_active will not include events in a cgroup other than the current task's. This makes rotation appear necessary for cgroups when it is not. Add a perf_event_context flag that is set when rotation is necessary. Clear the flag during sched_out and set it when a flexible sched_in fails due to resources. Signed-off-by:
Ian Rogers <irogers@google.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/20190601082722.44543-1-irogers@google.comSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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Jiri Olsa authored
Getting the apply_quirk bool from new rapl_model_match array. And because apply_quirk was the last remaining piece of data in rapl_cpu_match, replacing it with rapl_model_match as device table. The switch to new perf_msr_probe detection API is done. Signed-off-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
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Jiri Olsa authored
We no longer need model specific attribute arrays, because we get all this detected in rapl_events_attrs. Signed-off-by:
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Jiri Olsa authored
There's no need to have special code for getting the bit and MSR value for given event. We can now easily get it from rapl_msrs array. Also getting rid of RAPL_IDX_*, which is no longer needed and replacing INTEL_RAPL* with PERF_RAPL* enums. Signed-off-by:
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Jiri Olsa authored
We get rapl_cntr_mask from perf_msr_probe call, as a replacement for current intel_rapl_init_fun::cntr_mask value for each model. Signed-off-by:
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Jiri Olsa authored
Using perf_msr_probe function to probe for RAPL MSRs. Adding new rapl_model_match device table, that gathers events info for given model, following the MSR and cstate module design. It will replace the current rapl_cpu_match device table and detection code in following patches. Signed-off-by:
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Jiri Olsa authored
Using perf_msr_probe function to probe for cstate events. The functionality is the same, with one exception, that perf_msr_probe checks for rdmsr to return value != 0 for given MSR register. Using the new attribute groups and adding the events via pmu::attr_update. Signed-off-by:
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Jiri Olsa authored
Using perf_msr_probe function to probe for msr events. The functionality is the same, with one exception, that perf_msr_probe checks for rdmsr to return value != 0 for given MSR register. Using the new attribute groups and adding the events via pmu::attr_update. Signed-off-by:
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Jiri Olsa authored
Adding perf_msr_probe function to provide interface for checking up on MSR register and set the related attribute group visibility. User defines following struct for each MSR register: struct perf_msr { u64 msr; struct attribute_group *grp; bool (*test)(int idx, void *data); bool no_check; }; Where: msr - is the MSR address attrs - is attribute groups array to add if the check passed test - is test function pointer no_check - is bool that bypass the check and adds the attribute without any test The array of struct perf_msr is passed into: perf_msr_probe(struct perf_msr *msr, int cnt, bool zero, void *data) Together with: cnt - which is the number of struct msr array elements data - which is user pointer passed to the test function zero - allow counters that returns zero on rdmsr The perf_msr_probe will executed test code, read the MSR and check the value is != 0. If all these tests pass, related attribute group is kept visible. Also adding PMU_EVENT_GROUP macro helper to define attribute group for single attribute. It will be used in following patches. Signed-off-by: -
Ingo Molnar authored
Signed-off-by: -
Ingo Molnar authored
Signed-off-by:
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- 23 Jun, 2019 5 commits
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Fenghua Yu authored
Since two new sysfs interface files are created for umwait control, add an ABI document entry for the files: /sys/devices/system/cpu/umwait_control/enable_c02 /sys/devices/system/cpu/umwait_control/max_time [ tglx: Made the write value instructions readable ] Signed-off-by:
Fenghua Yu <fenghua.yu@intel.com> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Reviewed-by:
Ashok Raj <ashok.raj@intel.com> Cc: "Borislav Petkov" <bp@alien8.de> Cc: "H Peter Anvin" <hpa@zytor.com> Cc: "Andy Lutomirski" <luto@kernel.org> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Tony Luck" <tony.luck@intel.com> Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com> Link: https://lkml.kernel.org/r/1560994438-235698-6-git-send-email-fenghua.yu@intel.com
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Fenghua Yu authored
IA32_UMWAIT_CONTROL[31:2] determines the maximum time in TSC-quanta that processor can stay in C0.1 or C0.2. A zero value means no maximum time. Each instruction sets its own deadline in the instruction's implicit input EDX:EAX value. The instruction wakes up if the time-stamp counter reaches or exceeds the specified deadline, or the umwait maximum time expires, or a store happens in the monitored address range in umwait. The administrator can write an unsigned 32-bit number to /sys/devices/system/cpu/umwait_control/max_time to change the default value. Note that a value of zero means there is no limit. The lower two bits of the value must be zero. [ tglx: Simplify the write function. Massage changelog ] Signed-off-by:
Tony Luck <tony.luck@intel.com> Cc: "Borislav Petkov" <bp@alien8.de> Cc: "H Peter Anvin" <hpa@zytor.com> Cc: "Andy Lutomirski" <luto@kernel.org> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com> Link: https://lkml.kernel.org/r/1560994438-235698-5-git-send-email-fenghua.yu@intel.com
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Fenghua Yu authored
C0.2 state in umwait and tpause instructions can be enabled or disabled on a processor through IA32_UMWAIT_CONTROL MSR register. By default, C0.2 is enabled and the user wait instructions results in lower power consumption with slower wakeup time. But in real time systems which require faster wakeup time although power savings could be smaller, the administrator needs to disable C0.2 and all umwait invocations from user applications use C0.1. Create a sysfs interface which allows the administrator to control C0.2 state during run time. Andy Lutomirski suggested to turn off local irqs before writing the MSR to ensure the cached control value is not changed by a concurrent sysfs write from a different CPU via IPI. [ tglx: Simplified the update logic in the write function and got rid of all the convoluted type casts. Added a shared update function and made the namespace consistent. Moved the sysfs create invocation. Massaged changelog ] Signed-off-by:
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Fenghua Yu authored
umwait or tpause allows the processor to enter a light-weight power/performance optimized state (C0.1 state) or an improved power/performance optimized state (C0.2 state) for a period specified by the instruction or until the system time limit or until a store to the monitored address range in umwait. IA32_UMWAIT_CONTROL MSR register allows the OS to enable/disable C0.2 on the processor and to set the maximum time the processor can reside in C0.1 or C0.2. By default C0.2 is enabled so the user wait instructions can enter the C0.2 state to save more power with slower wakeup time. Andy Lutomirski proposed to set the maximum umwait time to 100000 cycles by default. A quote from Andy: "What I want to avoid is the case where it works dramatically differently on NO_HZ_FULL systems as compared to everything else. Also, UMWAIT may behave a bit differently if the max timeout is hit, and I'd like that path to get exercised widely by making it happen even on default configs." A sysfs interface to adjust the time and the C0.2 enablement is provided in a follow up change. [ tglx: Renamed MSR_IA32_UMWAIT_CONTROL_MAX_TIME to MSR_IA32_UMWAIT_CONTROL_TIME_MASK because the constant is used as mask throughout the code. Massaged comments and changelog ] Signed-off-by:
Andy Lutomirski <luto@kernel.org> Cc: "Borislav Petkov" <bp@alien8.de> Cc: "H Peter Anvin" <hpa@zytor.com> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Tony Luck" <tony.luck@intel.com> Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com> Link: https://lkml.kernel.org/r/1560994438-235698-3-git-send-email-fenghua.yu@intel.com
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Fenghua Yu authored
umonitor, umwait, and tpause are a set of user wait instructions. umonitor arms address monitoring hardware using an address. The address range is determined by using CPUID.0x5. A store to an address within the specified address range triggers the monitoring hardware to wake up the processor waiting in umwait. umwait instructs the processor to enter an implementation-dependent optimized state while monitoring a range of addresses. The optimized state may be either a light-weight power/performance optimized state (C0.1 state) or an improved power/performance optimized state (C0.2 state). tpause instructs the processor to enter an implementation-dependent optimized state C0.1 or C0.2 state and wake up when time-stamp counter reaches specified timeout. The three instructions may be executed at any privilege level. The instructions provide power saving method while waiting in user space. Additionally, they can allow a sibling hyperthread to make faster progress while this thread is waiting. One example of an application usage of umwait is when waiting for input data from another application, such as a user level multi-threaded packet processing engine. Availability of the user wait instructions is indicated by the presence of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5]. Detailed information on the instructions and CPUID feature WAITPKG flag can be found in the latest Intel Architecture Instruction Set Extensions and Future Features Programming Reference and Intel 64 and IA-32 Architectures Software Developer's Manual. Signed-off-by:
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- 22 Jun, 2019 22 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommuLinus Torvalds authored
Pull iommu fix from Joerg Roedel: "Revert a commit from the previous pile of fixes which causes new lockdep splats. It is better to revert it for now and work on a better and more well tested fix" * tag 'iommu-fix-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: Revert "iommu/vt-d: Fix lock inversion between iommu->lock and device_domain_lock"
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Peter Xu authored
This reverts commit 7560cc3c. With 5.2.0-rc5 I can easily trigger this with lockdep and iommu=pt: ====================================================== WARNING: possible circular locking dependency detected 5.2.0-rc5 #78 Not tainted ------------------------------------------------------ swapper/0/1 is trying to acquire lock: 00000000ea2b3beb (&(&iommu->lock)->rlock){+.+.}, at: domain_context_mapping_one+0xa5/0x4e0 but task is already holding lock: 00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (device_domain_lock){....}: _raw_spin_lock_irqsave+0x3c/0x50 dmar_insert_one_dev_info+0xbb/0x510 domain_add_dev_info+0x50/0x90 dev_prepare_static_identity_mapping+0x30/0x68 intel_iommu_init+0xddd/0x1422 pci_iommu_init+0x16/0x3f do_one_initcall+0x5d/0x2b4 kernel_init_freeable+0x218/0x2c1 kernel_init+0xa/0x100 ret_from_fork+0x3a/0x50 -> #0 (&(&iommu->lock)->rlock){+.+.}: lock_acquire+0x9e/0x170 _raw_spin_lock+0x25/0x30 domain_context_mapping_one+0xa5/0x4e0 pci_for_each_dma_alias+0x30/0x140 dmar_insert_one_dev_info+0x3b2/0x510 domain_add_dev_info+0x50/0x90 dev_prepare_static_identity_mapping+0x30/0x68 intel_iommu_init+0xddd/0x1422 pci_iommu_init+0x16/0x3f do_one_initcall+0x5d/0x2b4 kernel_init_freeable+0x218/0x2c1 kernel_init+0xa/0x100 ret_from_fork+0x3a/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(device_domain_lock); lock(&(&iommu->lock)->rlock); lock(device_domain_lock); lock(&(&iommu->lock)->rlock); *** DEADLOCK *** 2 locks held by swapper/0/1: #0: 00000000033eb13d (dmar_global_lock){++++}, at: intel_iommu_init+0x1e0/0x1422 #1: 00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0 stack backtrace: CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc5 #78 Hardware name: LENOVO 20KGS35G01/20KGS35G01, BIOS N23ET50W (1.25 ) 06/25/2018 Call Trace: dump_stack+0x85/0xc0 print_circular_bug.cold.57+0x15c/0x195 __lock_acquire+0x152a/0x1710 lock_acquire+0x9e/0x170 ? domain_context_mapping_one+0xa5/0x4e0 _raw_spin_lock+0x25/0x30 ? domain_context_mapping_one+0xa5/0x4e0 domain_context_mapping_one+0xa5/0x4e0 ? domain_context_mapping_one+0x4e0/0x4e0 pci_for_each_dma_alias+0x30/0x140 dmar_insert_one_dev_info+0x3b2/0x510 domain_add_dev_info+0x50/0x90 dev_prepare_static_identity_mapping+0x30/0x68 intel_iommu_init+0xddd/0x1422 ? printk+0x58/0x6f ? lockdep_hardirqs_on+0xf0/0x180 ? do_early_param+0x8e/0x8e ? e820__memblock_setup+0x63/0x63 pci_iommu_init+0x16/0x3f do_one_initcall+0x5d/0x2b4 ? do_early_param+0x8e/0x8e ? rcu_read_lock_sched_held+0x55/0x60 ? do_early_param+0x8e/0x8e kernel_init_freeable+0x218/0x2c1 ? rest_init+0x230/0x230 kernel_init+0xa/0x100 ret_from_fork+0x3a/0x50 domain_context_mapping_one() is taking device_domain_lock first then iommu lock, while dmar_insert_one_dev_info() is doing the reverse. That should be introduced by commit: 7560cc3c ("iommu/vt-d: Fix lock inversion between iommu->lock and device_domain_lock", 2019-05-27) So far I still cannot figure out how the previous deadlock was triggered (I cannot find iommu lock taken before calling of iommu_flush_dev_iotlb()), however I'm pretty sure that that change should be incomplete at least because it does not fix all the places so we're still taking the locks in different orders, while reverting that commit is very clean to me so far that we should always take device_domain_lock first then the iommu lock. We can continue to try to find the real culprit mentioned in 7560cc3c, but for now I think we should revert it to fix current breakage. CC: Joerg Roedel <joro@8bytes.org> CC: Lu Baolu <baolu.lu@linux.intel.com> CC: dave.jiang@intel.com Signed-off-by:
Peter Xu <peterx@redhat.com> Tested-by:
Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by:
Joerg Roedel <jroedel@suse.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pciLinus Torvalds authored
Pull PCI fix from Bjorn Helgaas: "If an IOMMU is present, ignore the P2PDMA whitelist we added for v5.2 because we don't yet know how to support P2PDMA in that case (Logan Gunthorpe)" * tag 'pci-v5.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: PCI/P2PDMA: Ignore root complex whitelist when an IOMMU is present
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Three driver fixes (and one version number update): a suspend hang in ufs, a qla hard lock on module removal and a qedi panic during discovery" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: qla2xxx: Fix hardlockup in abort command during driver remove scsi: ufs: Avoid runtime suspend possibly being blocked forever scsi: qedi: update driver version to 8.37.0.20 scsi: qedi: Check targetname while finding boot target information
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc fixes from Michael Ellerman: "This is a frustratingly large batch at rc5. Some of these were sent earlier but were missed by me due to being distracted by other things, and some took a while to track down due to needing manual bisection on old hardware. But still we clearly need to improve our testing of KVM, and of 32-bit, so that we catch these earlier. Summary: seven fixes, all for bugs introduced this cycle. - The commit to add KASAN support broke booting on 32-bit SMP machines, due to a refactoring that moved some setup out of the secondary CPU path. - A fix for another 32-bit SMP bug introduced by the fast syscall entry implementation for 32-bit BOOKE. And a build fix for the same commit. - Our change to allow the DAWR to be force enabled on Power9 introduced a bug in KVM, where we clobber r3 leading to a host crash. - The same commit also exposed a previously unreachable bug in the nested KVM handling of DAWR, which could lead to an oops in a nested host. - One of the DMA reworks broke the b43legacy WiFi driver on some people's powermacs, fix it by enabling a 30-bit ZONE_DMA on 32-bit. - A fix for TLB flushing in KVM introduced a new bug, as it neglected to also flush the ERAT, this could lead to memory corruption in the guest. Thanks to: Aaro Koskinen, Christoph Hellwig, Christophe Leroy, Larry Finger, Michael Neuling, Suraj Jitindar Singh" * tag 'powerpc-5.2-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac KVM: PPC: Book3S HV: Only write DAWR[X] when handling h_set_dawr in real mode KVM: PPC: Book3S HV: Fix r3 corruption in h_set_dabr() powerpc/32: fix build failure on book3e with KVM powerpc/booke: fix fast syscall entry on SMP powerpc/32s: fix initial setup of segment registers on secondary CPU -
Marcel Holtmann authored
When trying to align the minimum encryption key size requirement for Bluetooth connections, it turns out doing this in a central location in the HCI connection handling code is not possible. Original Bluetooth version up to 2.0 used a security model where the L2CAP service would enforce authentication and encryption. Starting with Bluetooth 2.1 and Secure Simple Pairing that model has changed into that the connection initiator is responsible for providing an encrypted ACL link before any L2CAP communication can happen. Now connecting Bluetooth 2.1 or later devices with Bluetooth 2.0 and before devices are causing a regression. The encryption key size check needs to be moved out of the HCI connection handling into the L2CAP channel setup. To achieve this, the current check inside hci_conn_security() has been moved into l2cap_check_enc_key_size() helper function and then called from four decisions point inside L2CAP to cover all combinations of Secure Simple Pairing enabled devices and device using legacy pairing and legacy service security model. Fixes: d5bb334a ("Bluetooth: Align minimum encryption key size for LE and BR/EDR connections") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203643Signed-off-by:
Marcel Holtmann <marcel@holtmann.org> Cc: stable@vger.kernel.org Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Konstantin Khlebnikov authored
Since commit 7d5905dc ("x86 / CPU: Always show current CPU frequency in /proc/cpuinfo") open and read of /proc/cpuinfo sends IPI to all CPUs. Many applications read /proc/cpuinfo at the start for trivial reasons like counting cores or detecting cpu features. While sensitive workloads like DPDK network polling don't like any interrupts. Integrates this feature with cpu isolation and do not send IPIs to CPUs without housekeeping flag HK_FLAG_MISC (set by nohz_full). Code that requests cpu frequency like show_cpuinfo() falls back to the last frequency set by the cpufreq driver if this method returns 0. Signed-off-by:
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by:
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Tony W Wang-oc authored
Same as Intel, Zhaoxin MP CPUs support C3 share cache and on all recent Zhaoxin platforms ARB_DISABLE is a nop. So set related flags correctly in the same way as Intel does. Signed-off-by:
Tony W Wang-oc <TonyWWang-oc@zhaoxin.com> Signed-off-by:
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Tony W Wang-oc authored
Zhaoxin CPUs have NONSTOP TSC feature, so enable the ACPI driver support for it. Signed-off-by:
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Tony W Wang-oc authored
Add x86 architecture support for new Zhaoxin processors. Carve out initialization code needed by Zhaoxin processors into a separate compilation unit. To identify Zhaoxin CPU, add a new vendor type X86_VENDOR_ZHAOXIN for system recognition. Signed-off-by:
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Andy Shevchenko authored
Split Tremont based Atoms from the rest to keep logical grouping. Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
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Thomas Gleixner authored
Explain how the GS/FS based addressing can be utilized in user space applications along with the differences between the generic prctl() based GS/FS base control and the FSGSBASE version available on newer CPUs. Originally-by:
Andi Kleen <ak@linux.intel.com> Signed-off-by:
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Andi Kleen authored
The kernel needs to explicitly enable FSGSBASE. So, the application needs to know if it can safely use these instructions. Just looking at the CPUID bit is not enough because it may be running in a kernel that does not enable the instructions. One way for the application would be to just try and catch the SIGILL. But that is difficult to do in libraries which may not want to overwrite the signal handlers of the main application. Enumerate the enabled FSGSBASE capability in bit 1 of AT_HWCAP2 in the ELF aux vector. AT_HWCAP2 is already used by PPC for similar purposes. The application can access it open coded or by using the getauxval() function in newer versions of glibc. [ tglx: Massaged changelog ] Signed-off-by:
Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by:
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Andy Lutomirski authored
Now that FSGSBASE is fully supported, remove unsafe_fsgsbase, enable FSGSBASE by default, and add nofsgsbase to disable it. Signed-off-by:
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Chang S. Bae authored
This validates that GS and GSBASE are independently preserved in ptracer commands. Suggested-by:
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Andy Lutomirski authored
This validates that GS and GSBASE are independently preserved across context switches. [ chang: Use FSGSBASE instructions directly instead of .byte ] Signed-off-by:
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Chang S. Bae authored
On a FSGSBASE system, the way to handle GSBASE in the paranoid path is different from the existing SWAPGS-based entry/exit path handling. Document the reason and what has to be done for FSGSBASE enabled systems. [ tglx: Massaged doc and changelog ] Signed-off-by:
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Chang S. Bae authored
Without FSGSBASE, user space cannot change GSBASE other than through a PRCTL. The kernel enforces that the user space GSBASE value is postive as negative values are used for detecting the kernel space GSBASE value in the paranoid entry code. If FSGSBASE is enabled, user space can set arbitrary GSBASE values without kernel intervention, including negative ones, which breaks the paranoid entry assumptions. To avoid this, paranoid entry needs to unconditionally save the current GSBASE value independent of the interrupted context, retrieve and write the kernel GSBASE and unconditionally restore the saved value on exit. The restore happens either in paranoid_exit or in the special exit path of the NMI low level code. All other entry code pathes which use unconditional SWAPGS are not affected as they do not depend on the actual content. [ tglx: Massaged changelogs and comments ] Suggested-by:
H. Peter Anvin <hpa@zytor.com> Suggested-by:
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Chang S. Bae authored
GSBASE is used to find per-CPU data in the kernel. But when GSBASE is unknown, the per-CPU base can be found from the per_cpu_offset table with a CPU NR. The CPU NR is extracted from the limit field of the CPUNODE entry in GDT, or by the RDPID instruction. This is a prerequisite for using FSGSBASE in the low level entry code. Also, add the GAS-compatible RDPID macro as binutils 2.21 do not support it. Support is added in version 2.27. [ tglx: Massaged changelog ] Suggested-by:
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Chang S. Bae authored
When FSGSBASE is enabled, the GSBASE handling in paranoid entry will need to retrieve the kernel GSBASE which requires that the kernel page table is active. As the CR3 switch to the kernel page tables (PTI is active) does not depend on kernel GSBASE, move the CR3 switch in front of the GSBASE handling. Comment the EBX content while at it. No functional change. [ tglx: Rewrote changelog and comments ] Signed-off-by:
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Chang S. Bae authored
When FSGSBASE is enabled, copying threads and reading fsbase and gsbase using ptrace must read the actual values. When copying a thread, use save_fsgs() and copy the saved values. For ptrace, the bases must be read from memory regardless of the selector if FSGSBASE is enabled. [ tglx: Invoke __rdgsbase_inactive() with interrupts disabled ] [ luto: Massage changelog ] Suggested-by:
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