- 20 Mar, 2020 4 commits
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Johannes Weiner authored
When switching tasks running on a CPU, the psi state of a cgroup containing both of these tasks does not change. Right now, we don't exploit that, and can perform many unnecessary state changes in nested hierarchies, especially when most activity comes from one leaf cgroup. This patch implements an optimization where we only update cgroups whose state actually changes during a task switch. These are all cgroups that contain one task but not the other, up to the first shared ancestor. When both tasks are in the same group, we don't need to update anything at all. We can identify the first shared ancestor by walking the groups of the incoming task until we see TSK_ONCPU set on the local CPU; that's the first group that also contains the outgoing task. The new psi_task_switch() is similar to psi_task_change(). To allow code reuse, move the task flag maintenance code into a new function and the poll/avg worker wakeups into the shared psi_group_change(). Suggested-by:
Peter Zijlstra <peterz@infradead.org> Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Johannes Weiner authored
For simplicity, cpu pressure is defined as having more than one runnable task on a given CPU. This works on the system-level, but it has limitations in a cgrouped reality: When cpu.max is in use, it doesn't capture the time in which a task is not executing on the CPU due to throttling. Likewise, it doesn't capture the time in which a competing cgroup is occupying the CPU - meaning it only reflects cgroup-internal competitive pressure, not outside pressure. Enable tracking of currently executing tasks, and then change the definition of cpu pressure in a cgroup from NR_RUNNING > 1 to NR_RUNNING > ON_CPU which will capture the effects of cpu.max as well as competition from outside the cgroup. After this patch, a cgroup running `stress -c 1` with a cpu.max setting of 5000 10000 shows ~50% continuous CPU pressure. Signed-off-by:
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Paul Turner authored
Currently, when updating the affinity of tasks via either cpusets.cpus, or, sched_setaffinity(); tasks not currently running within the newly specified mask will be arbitrarily assigned to the first CPU within the mask. This (particularly in the case that we are restricting masks) can result in many tasks being assigned to the first CPUs of their new masks. This: 1) Can induce scheduling delays while the load-balancer has a chance to spread them between their new CPUs. 2) Can antogonize a poor load-balancer behavior where it has a difficult time recognizing that a cross-socket imbalance has been forced by an affinity mask. This change adds a new cpumask interface to allow iterated calls to distribute within the intersection of the provided masks. The cases that this mainly affects are: - modifying cpuset.cpus - when tasks join a cpuset - when modifying a task's affinity via sched_setaffinity(2) Signed-off-by:Paul Turner <pjt@google.com> Signed-off-by:
Josh Don <joshdon@google.com> Signed-off-by:
Qais Yousef <qais.yousef@arm.com> Tested-by:
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Vincent Guittot authored
When a cfs rq is throttled, the latter and its child are removed from the leaf list but their nr_running is not changed which includes staying higher than 1. When a task is enqueued in this throttled branch, the cfs rqs must be added back in order to ensure correct ordering in the list but this can only happens if nr_running == 1. When cfs bandwidth is used, we call unconditionnaly list_add_leaf_cfs_rq() when enqueuing an entity to make sure that the complete branch will be added. Similarly unthrottle_cfs_rq() can stop adding cfs in the list when a parent is throttled. Iterate the remaining entity to ensure that the complete branch will be added in the list. Reported-by:
Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by:
Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by:
Dietmar Eggemann <dietmar.eggemann@arm.com> Tested-by:
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- 06 Mar, 2020 24 commits
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Ingo Molnar authored
drivers/base/arch_topology.c is only built if CONFIG_GENERIC_ARCH_TOPOLOGY=y, resulting in such build failures: cpufreq_cooling.c:(.text+0x1e7): undefined reference to `arch_set_thermal_pressure' Move it to sched/core.c instead, and keep it enabled on x86 despite us not having a arch_scale_thermal_pressure() facility there, to build-test this thing. Cc: Thara Gopinath <thara.gopinath@linaro.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:Ingo Molnar <mingo@kernel.org>
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Qais Yousef authored
In task_woken_rt() and switched_to_rto() we try trigger push-pull if the task is unfit. But the logic is found lacking because if the task was the only one running on the CPU, then rt_rq is not in overloaded state and won't trigger a push. The necessity of this logic was under a debate as well, a summary of the discussion can be found in the following thread: https://lore.kernel.org/lkml/20200226160247.iqvdakiqbakk2llz@e107158-lin.cambridge.arm.com/ Remove the logic for now until a better approach is agreed upon. Signed-off-by:
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Qais Yousef authored
When implemented RT Capacity Awareness; the logic was done such that if a task was running on a fitting CPU, then it was sticky and we would try our best to keep it there. But as Steve suggested, to adhere to the strict priority rules of RT class; allow pulling an RT task to unfitting CPU to ensure it gets a chance to run ASAP. LINK: https://lore.kernel.org/lkml/20200203111451.0d1da58f@oasis.local.home/Suggested-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Qais Yousef authored
By introducing a new cpupri_find_fitness() function that takes the fitness_fn as an argument and only called when asym_system static key is enabled. cpupri_find() is now a wrapper function that calls cpupri_find_fitness() passing NULL as a fitness_fn, hence disabling the logic that handles fitness by default. LINK: https://lore.kernel.org/lkml/c0772fca-0a4b-c88d-fdf2-5715fcf8447b@arm.com/Reported-by:
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Qais Yousef authored
When RT Capacity Aware support was added, the logic in select_task_rq_rt was modified to force a search for a fitting CPU if the task currently doesn't run on one. But if the search failed, and the search was only triggered to fulfill the fitness request; we could end up selecting a new CPU unnecessarily. Fix this and re-instate the original behavior by ensuring we bail out in that case. This behavior change only affected asymmetric systems that are using util_clamp to implement capacity aware. None asymmetric systems weren't affected. LINK: https://lore.kernel.org/lkml/20200218041620.GD28029@codeaurora.org/Reported-by:
Pavan Kondeti <pkondeti@codeaurora.org> Signed-off-by:
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Qais Yousef authored
When searching for the best lowest_mask with a fitness_fn passed, make sure we record the lowest_level that returns a valid lowest_mask so that we can use that as a fallback in case we fail to find a fitting CPU at all levels. The intention in the original patch was not to allow a down migration to unfitting CPU. But this missed the case where we are already running on unfitting one. With this change now RT tasks can still move between unfitting CPUs when they're already running on such CPU. And as Steve suggested; to adhere to the strict priority rules of RT, if a task is already running on a fitting CPU but due to priority it can't run on it, allow it to downmigrate to unfitting CPU so it can run. Reported-by:
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Vincent Guittot authored
Even when a cgroup is throttled, the group se of a child cgroup can still be enqueued and its gse->on_rq stays true. When a task is enqueued on such child, we still have to update the load_avg and increase h_nr_running of the throttled cfs. Nevertheless, the 1st for_each_sched_entity() loop is skipped because of gse->on_rq == true and the 2nd loop because the cfs is throttled whereas we have to update both load_avg with the old h_nr_running and increase h_nr_running in such case. The same sequence can happen during dequeue when se moves to parent before breaking in the 1st loop. Note that the update of load_avg will effectively happen only once in order to sync up to the throttled time. Next call for updating load_avg will stop early because the clock stays unchanged. Signed-off-by:
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Vincent Guittot authored
When a cfs_rq is throttled, its group entity is dequeued and its running tasks are removed. We must update runnable_avg with the old h_nr_running and update group_se->runnable_weight with the new h_nr_running at each level of the hierarchy. Reviewed-by:
Ben Segall <bsegall@google.com> Signed-off-by:
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Yu Chen authored
Since commit 06a76fe0 ("sched/deadline: Move DL related code from sched/core.c to sched/deadline.c"), DL related code moved to deadline.c. Make the following two functions static since they're only used in deadline.c: dl_change_utilization() init_dl_rq_bw_ratio() Signed-off-by:
Yu Chen <chen.yu@easystack.cn> Signed-off-by:
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Valentin Schneider authored
The (CFS) scheduler has some extra logic catering to systems with SMT, but that logic won't be compiled in unless the above config is set. Note that the SMT-centric codepaths are gated by the sched_smt_present static key, and the SMT sched_domains will only survive if the platform has SMT. As such, the only impact on !SMT platforms should be a slightly bigger kernel - no behavioural change. Distro kernels already enable it, which makes sense since there already are things like ThunderX2 out in the wild. Enable it for the defconfig. Some deltas =========== FWIW my ELF symbol table diff looks something like this: NAME BEFORE AFTER DELTA update_sd_lb_stats.constprop.135 0 1864 +1864 find_idlest_group.isra.115 0 1808 +1808 update_numa_stats.isra.121 0 628 +628 select_task_rq_fair 3236 3732 +496 compute_energy.isra.112 0 420 +420 score_nearby_nodes.part.120 0 380 +380 __update_idle_core 0 232 +232 nohz_balance_exit_idle.part.127 0 216 +216 sched_slice.isra.99 0 172 +172 update_load_avg.part.107 0 116 +116 wakeup_preempt_entity.isra.101 0 92 +92 sched_cpu_activate 340 396 +56 pick_next_task_idle 8 56 +48 sched_cpu_deactivate 252 292 +40 show_smt_active 44 80 +36 cpu_smt_mask 0 28 +28 set_next_task_idle 4 32 +28 task_numa_work 680 692 +12 cpu_smt_flags 0 8 +8 enqueue_task_fair 2608 2612 +4 wakeup_preempt_entity.isra.104 92 0 -92 update_load_avg 1028 932 -96 task_numa_migrate 1824 1728 -96 sched_slice.isra.102 172 0 -172 nohz_balance_exit_idle.part.130 216 0 -216 task_numa_find_cpu 2116 1868 -248 score_nearby_nodes.part.123 380 0 -380 compute_energy.isra.115 420 0 -420 update_numa_stats.isra.124 472 0 -472 find_idlest_group.isra.118 1808 0 -1808 update_sd_lb_stats.constprop.138 1864 0 -1864 ------------------------------------------------------------------ DELTA SUM +820 As for the sched_domains, this is on a hikey960: before: $ cat /proc/sys/kernel/sched_domain/cpu*/domain*/name | sort | uniq DIE MC after: $ cat /proc/sys/kernel/sched_domain/cpu*/domain*/name | sort | uniq DIE MC Reviewed-by:
Valentin Schneider <valentin.schneider@arm.com> Signed-off-by:
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Valentin Schneider authored
EAS already requires asymmetric CPU capacities to be enabled, and mixing this with SMT is an aberration, but better be safe than sorry. Reviewed-by:
Quentin Perret <qperret@google.com> Signed-off-by:
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Mel Gorman authored
Qian Cai reported the following bug: The linux-next commit ff7db0bf ("sched/numa: Prefer using an idle CPU as a migration target instead of comparing tasks") introduced a boot warning, [ 86.520534][ T1] WARNING: suspicious RCU usage [ 86.520540][ T1] 5.6.0-rc3-next-20200227 #7 Not tainted [ 86.520545][ T1] ----------------------------- [ 86.520551][ T1] kernel/sched/fair.c:5914 suspicious rcu_dereference_check() usage! [ 86.520555][ T1] [ 86.520555][ T1] other info that might help us debug this: [ 86.520555][ T1] [ 86.520561][ T1] [ 86.520561][ T1] rcu_scheduler_active = 2, debug_locks = 1 [ 86.520567][ T1] 1 lock held by systemd/1: [ 86.520571][ T1] #0: ffff8887f4b14848 (&mm->mmap_sem#2){++++}, at: do_page_fault+0x1d2/0x998 [ 86.520594][ T1] [ 86.520594][ T1] stack backtrace: [ 86.520602][ T1] CPU: 1 PID: 1 Comm: systemd Not tainted 5.6.0-rc3-next-20200227 #7 task_numa_migrate() checks for idle cores when updating NUMA-related statistics. This relies on reading a RCU-protected structure in test_idle_cores() via this call chain task_numa_migrate -> update_numa_stats -> numa_idle_core -> test_idle_cores While the locking could be fine-grained, it is more appropriate to acquire the RCU lock for the entire scan of the domain. This patch removes the warning triggered at boot time. Reported-by:
Qian Cai <cai@lca.pw> Reviewed-by:
Paul E. McKenney <paulmck@kernel.org> Signed-off-by:
Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
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Valentin Schneider authored
Building against the tip/sched/core as ff7db0bf ("sched/numa: Prefer using an idle CPU as a migration target instead of comparing tasks") with the arm64 defconfig (which doesn't have CONFIG_SCHED_SMT set) leads to: kernel/sched/fair.c:1525:20: warning: 'test_idle_cores' declared 'static' but never defined [-Wunused-function] static inline bool test_idle_cores(int cpu, bool def); ^~~~~~~~~~~~~~~ Rather than define it in its own CONFIG_SCHED_SMT #define island, bunch it up with test_idle_cores(). Reported-by:
Anshuman Khandual <anshuman.khandual@arm.com> Reported-by:
Naresh Kamboju <naresh.kamboju@linaro.org> Reviewed-by:
Lukasz Luba <lukasz.luba@arm.com> [mgorman@techsingularity.net: Edit changelog, minor style change] Signed-off-by:
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Thara Gopinath authored
Thermal pressure follows pelt signals which means the decay period for thermal pressure is the default pelt decay period. Depending on SoC characteristics and thermal activity, it might be beneficial to decay thermal pressure slower, but still in-tune with the pelt signals. One way to achieve this is to provide a command line parameter to set a decay shift parameter to an integer between 0 and 10. Signed-off-by:
Thara Gopinath <thara.gopinath@linaro.org> Signed-off-by:
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Thara Gopinath authored
Thermal governors can request for a CPU's maximum supported frequency to be capped in case of an overheat event. This in turn means that the maximum capacity available for tasks to run on the particular CPU is reduced. Delta between the original maximum capacity and capped maximum capacity is known as thermal pressure. Enable cpufreq cooling device to update the thermal pressure in event of a capped maximum frequency. Signed-off-by:
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Thara Gopinath authored
cpu_capacity initially reflects the maximum possible capacity of a CPU. Thermal pressure on a CPU means this maximum possible capacity is unavailable due to thermal events. This patch subtracts the average thermal pressure for a CPU from its maximum possible capacity so that cpu_capacity reflects the remaining maximum capacity. Signed-off-by:
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Thara Gopinath authored
Introduce support in scheduler periodic tick and other CFS bookkeeping APIs to trigger the process of computing average thermal pressure for a CPU. Also consider avg_thermal.load_avg in others_have_blocked which allows for decay of pelt signals. Signed-off-by:
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Thara Gopinath authored
Hook up topology_get_thermal_pressure to arch_scale_thermal_pressure thus enabling scheduler to retrieve instantaneous thermal pressure of a CPU. Signed-off-by:
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Thara Gopinath authored
Hook up topology_get_thermal_pressure to arch_scale_thermal_pressure thus enabling scheduler to retrieve instantaneous thermal pressure of a CPU. Signed-off-by:
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Thara Gopinath authored
Add architecture specific APIs to update and track thermal pressure on a per CPU basis. A per CPU variable thermal_pressure is introduced to keep track of instantaneous per CPU thermal pressure. Thermal pressure is the delta between maximum capacity and capped capacity due to a thermal event. topology_get_thermal_pressure can be hooked into the scheduler specified arch_scale_thermal_pressure to retrieve instantaneous thermal pressure of a CPU. arch_set_thermal_pressure can be used to update the thermal pressure. Considering topology_get_thermal_pressure reads thermal_pressure and arch_set_thermal_pressure writes into thermal_pressure, one can argue for some sort of locking mechanism to avoid a stale value. But considering topology_get_thermal_pressure can be called from a system critical path like scheduler tick function, a locking mechanism is not ideal. This means that it is possible the thermal_pressure value used to calculate average thermal pressure for a CPU can be stale for up to 1 tick period. Signed-off-by:
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Thara Gopinath authored
Introduce the arch_scale_thermal_pressure() callback to retrieve per CPU thermal pressure. Signed-off-by:
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Thara Gopinath authored
Extrapolating on the existing framework to track rt/dl utilization using pelt signals, add a similar mechanism to track thermal pressure. The difference here from rt/dl utilization tracking is that, instead of tracking time spent by a CPU running a RT/DL task through util_avg, the average thermal pressure is tracked through load_avg. This is because thermal pressure signal is weighted time "delta" capacity unlike util_avg which is binary. "delta capacity" here means delta between the actual capacity of a CPU and the decreased capacity a CPU due to a thermal event. In order to track average thermal pressure, a new sched_avg variable avg_thermal is introduced. Function update_thermal_load_avg can be called to do the periodic bookkeeping (accumulate, decay and average) of the thermal pressure. Reviewed-by:
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Chris Wilson authored
As the vtime is sampled under loose seqcount protection by kcpustat, the vtime fields may change as the code flows. Where logic dictates a field has a static value, use a READ_ONCE. Signed-off-by:
Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by:
Frederic Weisbecker <frederic@kernel.org> Signed-off-by:
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Ingo Molnar authored
Signed-off-by:
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- 03 Mar, 2020 1 commit
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git://git.samba.org/sfrench/cifs-2.6Linus Torvalds authored
Pull cifs fixes from Steve French: "Five small cifs/smb3 fixes, two for stable (one for a reconnect problem and the other fixes a use case when renaming an open file)" * tag '5.6-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: Use #define in cifs_dbg cifs: fix rename() by ensuring source handle opened with DELETE bit cifs: add missing mount option to /proc/mounts cifs: fix potential mismatch of UNC paths cifs: don't leak -EAGAIN for stat() during reconnect
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- 02 Mar, 2020 4 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Ingo Molnar: "Misc fixes: a pkeys fix for a bug that triggers with weird BIOS settings, and two Xen PV fixes: a paravirt interface fix, and pagetable dumping fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Fix dump_pagetables with Xen PV x86/ioperm: Add new paravirt function update_io_bitmap() x86/pkeys: Manually set X86_FEATURE_OSPKE to preserve existing changes
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull scheduler fix from Ingo Molnar: "Fix a scheduler statistics bug" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix statistics for find_idlest_group()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf fixes from Ingo Molnar: "No kernel side changes, all tooling fixes plus two tooling cleanups that were committed late in the merge window alongside the perf annotate fixes, delayed by Arnaldo's European trip" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) perf annotate: Fix segfault with source toggle perf annotate: Align struct annotate_args perf annotate: Simplify disasm_line allocation and freeing code perf annotate: Remove privsize from symbol__annotate() args perf probe: Check return value of strlist__add() for -ENOMEM perf config: Document missing config options perf annotate: Fix perf config option description perf annotate: Prefer cmdline option over default config perf annotate: Make perf config effective perf config: Introduce perf_config_u8() perf annotate: Fix --show-nr-samples for tui/stdio2 perf annotate: Fix --show-total-period for tui/stdio2 perf annotate/tui: Re-render title bar after switching back from script browser tools headers UAPI: Update tools's copy of kvm.h headers tools arch x86: Sync the msr-index.h copy with the kernel sources perf arch powerpc: Sync powerpc syscall.tbl with the kernel sources perf auxtrace: Add auxtrace_record__read_finish() perf arm-spe: Fix endless record after being terminated perf cs-etm: Fix endless record after being terminated perf intel-bts: Fix endless record after being terminated ...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull EFI fixes from Ingo Molnar: "Three fixes to EFI mixed boot mode, mostly related to x86-64 vmap stacks activated years ago, bug-fixed recently for EFI, which had knock-on effects of various 1:1 mapping assumptions in mixed mode. There's also a READ_ONCE() fix for reading an mmap-ed EFI firmware data field only once, out of caution" * 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: READ_ONCE rng seed size before munmap efi/x86: Handle by-ref arguments covering multiple pages in mixed mode efi/x86: Remove support for EFI time and counter services in mixed mode efi/x86: Align GUIDs to their size in the mixed mode runtime wrapper
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- 01 Mar, 2020 5 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4Linus Torvalds authored
Pull ext4 fixes from Ted Ts'o: "Two more bug fixes (including a regression) for 5.6" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: potential crash on allocation error in ext4_alloc_flex_bg_array() jbd2: fix data races at struct journal_head
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git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull KVM fixes from Paolo Bonzini: "More bugfixes, including a few remaining "make W=1" issues such as too large frame sizes on some configurations. On the ARM side, the compiler was messing up shadow stacks between EL1 and EL2 code, which is easily fixed with __always_inline" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: VMX: check descriptor table exits on instruction emulation kvm: x86: Limit the number of "kvm: disabled by bios" messages KVM: x86: avoid useless copy of cpufreq policy KVM: allow disabling -Werror KVM: x86: allow compiling as non-module with W=1 KVM: Pre-allocate 1 cpumask variable per cpu for both pv tlb and pv ipis KVM: Introduce pv check helpers KVM: let declaration of kvm_get_running_vcpus match implementation KVM: SVM: allocate AVIC data structures based on kvm_amd module parameter arm64: Ask the compiler to __always_inline functions used by KVM at HYP KVM: arm64: Define our own swab32() to avoid a uapi static inline KVM: arm64: Ask the compiler to __always_inline functions used at HYP kvm: arm/arm64: Fold VHE entry/exit work into kvm_vcpu_run_vhe() KVM: arm/arm64: Fix up includes for trace.h
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Oliver Upton authored
KVM emulates UMIP on hardware that doesn't support it by setting the 'descriptor table exiting' VM-execution control and performing instruction emulation. When running nested, this emulation is broken as KVM refuses to emulate L2 instructions by default. Correct this regression by allowing the emulation of descriptor table instructions if L1 hasn't requested 'descriptor table exiting'. Fixes: 07721fee ("KVM: nVMX: Don't emulate instructions in guest mode") Reported-by:
Jan Kiszka <jan.kiszka@web.de> Cc: stable@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by:
Oliver Upton <oupton@google.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linuxLinus Torvalds authored
Pull i2c fixes from Wolfram Sang: "I2C has three driver bugfixes for you. We agreed on the Mac regression to go in via I2C" * 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: macintosh: therm_windtunnel: fix regression when instantiating devices i2c: altera: Fix potential integer overflow i2c: jz4780: silence log flood on txabrt
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- 29 Feb, 2020 2 commits
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Dan Carpenter authored
If sbi->s_flex_groups_allocated is zero and the first allocation fails then this code will crash. The problem is that "i--" will set "i" to -1 but when we compare "i >= sbi->s_flex_groups_allocated" then the -1 is type promoted to unsigned and becomes UINT_MAX. Since UINT_MAX is more than zero, the condition is true so we call kvfree(new_groups[-1]). The loop will carry on freeing invalid memory until it crashes. Fixes: 7c990728 ("ext4: fix potential race between s_flex_groups online resizing and access") Reviewed-by:
Suraj Jitindar Singh <surajjs@amazon.com> Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@kernel.org Link: https://lore.kernel.org/r/20200228092142.7irbc44yaz3by7nb@kili.mountainSigned-off-by:
Theodore Ts'o <tytso@mit.edu>
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Wolfram Sang authored
Removing attach_adapter from this driver caused a regression for at least some machines. Those machines had the sensors described in their DT, too, so they didn't need manual creation of the sensor devices. The old code worked, though, because manual creation came first. Creation of DT devices then failed later and caused error logs, but the sensors worked nonetheless because of the manually created devices. When removing attach_adaper, manual creation now comes later and loses the race. The sensor devices were already registered via DT, yet with another binding, so the driver could not be bound to it. This fix refactors the code to remove the race and only manually creates devices if there are no DT nodes present. Also, the DT binding is updated to match both, the DT and manually created devices. Because we don't know which device creation will be used at runtime, the code to start the kthread is moved to do_probe() which will be called by both methods. Fixes: 3e7bed52 ("macintosh: therm_windtunnel: drop using attach_adapter") Link: https://bugzilla.kernel.org/show_bug.cgi?id=201723Reported-by:
Erhard Furtner <erhard_f@mailbox.org> Tested-by:
Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org # v4.19+
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