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2023-10-10sched/numa: Complete scanning of partial VMAs regardless of PID activityMel Gorman3-4/+18
NUMA Balancing skips VMAs when the current task has not trapped a NUMA fault within the VMA. If the VMA is skipped then mm->numa_scan_offset advances and a task that is trapping faults within the VMA may never fully update PTEs within the VMA. Force tasks to update PTEs for partially scanned PTEs. The VMA will be tagged for NUMA hints by some task but this removes some of the benefit of tracking PID activity within a VMA. A follow-on patch will mitigate this problem. The test cases and machines evaluated did not trigger the corner case so the performance results are neutral with only small changes within the noise from normal test-to-test variance. However, the next patch makes the corner case easier to trigger. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Raghavendra K T <raghavendra.kt@amd.com> Link: https://lore.kernel.org/r/20231010083143.19593-6-mgorman@techsingularity.net
2023-10-10sched/numa: Move up the access pid reset logicRaghavendra K T1-10/+7
Recent NUMA hinting faulting activity is reset approximately every VMA_PID_RESET_PERIOD milliseconds. However, if the current task has not accessed a VMA then the reset check is missed and the reset is potentially deferred forever. Check if the PID activity information should be reset before checking if the current task recently trapped a NUMA hinting fault. [ mgorman@techsingularity.net: Rewrite changelog ] Suggested-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Raghavendra K T <raghavendra.kt@amd.com> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231010083143.19593-5-mgorman@techsingularity.net
2023-10-10sched/numa: Trace decisions related to skipping VMAsMel Gorman3-4/+71
NUMA balancing skips or scans VMAs for a variety of reasons. In preparation for completing scans of VMAs regardless of PID access, trace the reasons why a VMA was skipped. In a later patch, the tracing will be used to track if a VMA was forcibly scanned. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231010083143.19593-4-mgorman@techsingularity.net
2023-10-10sched/numa: Rename vma_numab_state::access_pids[] => ::pids_active[], ↵Mel Gorman3-11/+11
::next_pid_reset => ::pids_active_reset The access_pids[] field name is somewhat ambiguous as no PIDs are accessed. Similarly, it's not clear that next_pid_reset is related to access_pids[]. Rename the fields to more accurately reflect their purpose. [ mingo: Rename in the comments too. ] Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231010083143.19593-3-mgorman@techsingularity.net
2023-10-10sched/numa: Document vma_numab_state fieldsMel Gorman1-0/+21
Document the intended usage of the fields. [ mingo: Reformatted to take less vertical space & tidied it up. ] Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231010083143.19593-2-mgorman@techsingularity.net
2023-10-09sched/topology: Move the declaration of 'schedutil_gov' to kernel/sched/sched.hIngo Molnar2-1/+2
Move it out of the .c file into the shared scheduler-internal header file, to gain type-checking. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Shrikanth Hegde <sshegde@linux.vnet.ibm.com> Cc: Valentin Schneider <vschneid@redhat.com> Link: https://lore.kernel.org/r/20231009060037.170765-3-sshegde@linux.vnet.ibm.com
2023-10-09sched/topology: Change behaviour of the 'sched_energy_aware' sysctl, based ↵Shrikanth Hegde2-39/+76
on the platform The 'sched_energy_aware' sysctl is available for the admin to disable/enable energy aware scheduling(EAS). EAS is enabled only if few conditions are met by the platform. They are, asymmetric CPU capacity, no SMT, schedutil CPUfreq governor, frequency invariant load tracking etc. A platform may boot without EAS capability, but could gain such capability at runtime. For example, changing/registering the cpufreq governor to schedutil. At present, though platform doesn't support EAS, this sysctl returns 1 and it ends up calling build_perf_domains on write to 1 and NOP when writing to 0. That is confusing and un-necessary. Desired behavior would be to have this sysctl to enable/disable the EAS on supported platform. On non-supported platform write to the sysctl would return not supported error and read of the sysctl would return empty. So sched_energy_aware returns empty - EAS is not possible at this moment This will include EAS capable platforms which have at least one EAS condition false during startup, e.g. not using the schedutil cpufreq governor sched_energy_aware returns 0 - EAS is supported but disabled by admin. sched_energy_aware returns 1 - EAS is supported and enabled. User can find out the reason why EAS is not possible by checking info messages. sched_is_eas_possible returns true if the platform can do EAS at this moment. Signed-off-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Valentin Schneider <vschneid@redhat.com> Link: https://lore.kernel.org/r/20231009060037.170765-3-sshegde@linux.vnet.ibm.com
2023-10-09sched/psi: Change update_triggers() to a 'void' functionYang Yang1-4/+3
Update_triggers() always returns now + group->rtpoll_min_period, and the return value is only used by psi_rtpoll_work(), so change update_triggers() to a void function, let group->rtpoll_next_update = now + group->rtpoll_min_period directly. This will avoid unnecessary function return value passing & simplifies the function. [ mingo: Updated changelog ] Suggested-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/202310092024289721617@zte.com.cn
2023-10-09sched/topology: Remove the EM_MAX_COMPLEXITY limitPierre Gondois2-62/+6
The Energy Aware Scheduler (EAS) estimates the energy consumption of placing a task on different CPUs. The goal is to minimize this energy consumption. Estimating the energy of different task placements is increasingly complex with the size of the platform. To avoid having a slow wake-up path, EAS is only enabled if this complexity is low enough. The current complexity limit was set in: b68a4c0dba3b1 ("sched/topology: Disable EAS on inappropriate platforms") ... based on the first implementation of EAS, which was re-computing the power of the whole platform for each task placement scenario, see: 390031e4c309 ("sched/fair: Introduce an energy estimation helper function") ... but the complexity of EAS was reduced in: eb92692b2544d ("sched/fair: Speed-up energy-aware wake-ups") ... and find_energy_efficient_cpu() (feec) algorithm was updated in: 3e8c6c9aac42 ("sched/fair: Remove task_util from effective utilization in feec()") find_energy_efficient_cpu() (feec) is now doing: feec() \_ for_each_pd(pd) [0] // get max_spare_cap_cpu and compute_prev_delta \_ for_each_cpu(pd) [1] \_ eenv_pd_busy_time(pd) [2] \_ for_each_cpu(pd) // compute_energy(pd) without the task \_ eenv_pd_max_util(pd, -1) [3.0] \_ for_each_cpu(pd) \_ em_cpu_energy(pd, -1) \_ for_each_ps(pd) // compute_energy(pd) with the task on prev_cpu \_ eenv_pd_max_util(pd, prev_cpu) [3.1] \_ for_each_cpu(pd) \_ em_cpu_energy(pd, prev_cpu) \_ for_each_ps(pd) // compute_energy(pd) with the task on max_spare_cap_cpu \_ eenv_pd_max_util(pd, max_spare_cap_cpu) [3.2] \_ for_each_cpu(pd) \_ em_cpu_energy(pd, max_spare_cap_cpu) \_ for_each_ps(pd) [3.1] happens only once since prev_cpu is unique. With the same definitions for nr_pd, nr_cpus and nr_ps, the complexity is of: nr_pd * (2 * [nr_cpus in pd] + 2 * ([nr_cpus in pd] + [nr_ps in pd])) + ([nr_cpus in pd] + [nr_ps in pd]) [0] * ( [1] + [2] + [3.0] + [3.2] ) + [3.1] = nr_pd * (4 * [nr_cpus in pd] + 2 * [nr_ps in pd]) + [nr_cpus in prev pd] + nr_ps The complexity limit was set to 2048 in: b68a4c0dba3b1 ("sched/topology: Disable EAS on inappropriate platforms") ... to make "EAS usable up to 16 CPUs with per-CPU DVFS and less than 8 performance states each". For the same platform, the complexity would actually be of: 16 * (4 + 2 * 7) + 1 + 7 = 296 Since the EAS complexity was greatly reduced since the limit was introduced, bigger platforms can handle EAS. For instance, a platform with 112 CPUs with 7 performance states each would not reach it: 112 * (4 + 2 * 7) + 1 + 7 = 2024 To reflect this improvement in the underlying EAS code, remove the EAS complexity check. Note that a limit on the number of CPUs still holds against EM_MAX_NUM_CPUS to avoid overflows during the energy estimation. [ mingo: Updates to the changelog. ] Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lore.kernel.org/r/20231009060037.170765-2-sshegde@linux.vnet.ibm.com
2023-10-09sched/topology: Consolidate and clean up access to a CPU's max compute capacityVincent Guittot8-29/+25
Remove the rq::cpu_capacity_orig field and use arch_scale_cpu_capacity() instead. The scheduler uses 3 methods to get access to a CPU's max compute capacity: - arch_scale_cpu_capacity(cpu) which is the default way to get a CPU's capacity. - cpu_capacity_orig field which is periodically updated with arch_scale_cpu_capacity(). - capacity_orig_of(cpu) which encapsulates rq->cpu_capacity_orig. There is no real need to save the value returned by arch_scale_cpu_capacity() in struct rq. arch_scale_cpu_capacity() returns: - either a per_cpu variable. - or a const value for systems which have only one capacity. Remove rq::cpu_capacity_orig and use arch_scale_cpu_capacity() everywhere. No functional changes. Some performance tests on Arm64: - small SMP device (hikey): no noticeable changes - HMP device (RB5): hackbench shows minor improvement (1-2%) - large smp (thx2): hackbench and tbench shows minor improvement (1%) Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lore.kernel.org/r/20231009103621.374412-2-vincent.guittot@linaro.org
2023-10-09sched/rt: Change the type of 'sysctl_sched_rt_period' from 'unsigned int' to ↵Yajun Deng2-4/+4
'int' Doing this matches the natural type of 'int' based calculus in sched_rt_handler(), and also enables the adding in of a correct upper bounds check on the sysctl interface. [ mingo: Rewrote the changelog. ] Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231008021538.3063250-1-yajun.deng@linux.dev
2023-10-09sched/nohz: Remove unnecessarily complex error handling pattern from ↵Ingo Molnar1-3/+2
find_new_ilb() find_new_ilb() returns nr_cpu_ids on failure - which is the usual cpumask bitops return pattern, but is weird & unnecessary in this context: not only is it a global variable, it it is a +1 out of bounds CPU index and also has different signedness ... Its only user, kick_ilb(), then checks the return against nr_cpu_ids to decide to return. There's no other use. So instead of this, use a standard -1 return on failure to find an idle CPU, as the argument is signed already. Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Link: https://lore.kernel.org/r/20231006102518.2452758-4-mingo@kernel.org
2023-10-09sched/nohz: Use consistent variable names in find_new_ilb() and kick_ilb()Ingo Molnar1-5/+5
Use 'ilb_cpu' consistently in both functions. Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Link: https://lore.kernel.org/r/20231006102518.2452758-3-mingo@kernel.org
2023-10-09sched/nohz: Update idle load-balancing (ILB) commentsIngo Molnar1-14/+16
- Fix incorrect/misleading comments, - clarify some others, - fix typos & grammar, - and use more consistent style throughout. Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Link: https://lore.kernel.org/r/20231006102518.2452758-2-mingo@kernel.org
2023-10-07sched/debug: Print 'tgid' in sched_show_task()Yajun Deng1-3/+3
Multiple blocked tasks are printed when the system hangs. They may have the same parent pid, but belong to different task groups. Printing tgid lets users better know whether these tasks are from the same task group or not. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230720080516.1515297-1-yajun.deng@linux.dev
2023-10-07intel_idle: Add ibrs_off module parameter to force-disable IBRSWaiman Long2-2/+26
Commit bf5835bcdb96 ("intel_idle: Disable IBRS during long idle") disables IBRS when the cstate is 6 or lower. However, there are some use cases where a customer may want to use max_cstate=1 to lower latency. Such use cases will suffer from the performance degradation caused by the enabling of IBRS in the sibling idle thread. Add a "ibrs_off" module parameter to force disable IBRS and the CPUIDLE_FLAG_IRQ_ENABLE flag if set. In the case of a Skylake server with max_cstate=1, this new ibrs_off option will likely increase the IRQ response latency as IRQ will now be disabled. When running SPECjbb2015 with cstates set to C1 on a Skylake system. First test when the kernel is booted with: "intel_idle.ibrs_off": max-jOPS = 117828, critical-jOPS = 66047 Then retest when the kernel is booted without the "intel_idle.ibrs_off" added: max-jOPS = 116408, critical-jOPS = 58958 That means booting with "intel_idle.ibrs_off" improves performance by: max-jOPS: +1.2%, which could be considered noise range. critical-jOPS: +12%, which is definitely a solid improvement. The admin-guide/pm/intel_idle.rst file is updated to add a description about the new "ibrs_off" module parameter. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20230727184600.26768-5-longman@redhat.com
2023-10-07intel_idle: Use __update_spec_ctrl() in intel_idle_ibrs()Waiman Long1-4/+3
When intel_idle_ibrs() is called, it modifies the SPEC_CTRL MSR to 0 in order disable IBRS. However, the new MSR value isn't reflected in x86_spec_ctrl_current which is at odd with the other code that keep track of its state in that percpu variable. Use the new __update_spec_ctrl() to have the x86_spec_ctrl_current percpu value properly updated. Since spec-ctrl.h includes both msr.h and nospec-branch.h, we can remove those from the include file list. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20230727184600.26768-4-longman@redhat.com
2023-10-07x86/idle: Disable IBRS when CPU is offline to improve single-threaded ↵Waiman Long1-0/+8
performance Commit bf5835bcdb96 ("intel_idle: Disable IBRS during long idle") disables IBRS when the CPU enters long idle. However, when a CPU becomes offline, the IBRS bit is still set when X86_FEATURE_KERNEL_IBRS is enabled. That will impact the performance of a sibling CPU. Mitigate this performance impact by clearing all the mitigation bits in SPEC_CTRL MSR when offline. When the CPU is online again, it will be re-initialized and so restoring the SPEC_CTRL value isn't needed. Add a comment to say that native_play_dead() is a __noreturn function, but it can't be marked as such to avoid confusion about the missing MSR restoration code. When DPDK is running on an isolated CPU thread processing network packets in user space while its sibling thread is idle. The performance of the busy DPDK thread with IBRS on and off in the sibling idle thread are: IBRS on IBRS off ------- -------- packets/second: 7.8M 10.4M avg tsc cycles/packet: 282.26 209.86 This is a 25% performance degradation. The test system is a Intel Xeon 4114 CPU @ 2.20GHz. [ mingo: Extended the changelog with performance data from the 0/4 mail. ] Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20230727184600.26768-3-longman@redhat.com
2023-10-07x86/speculation: Add __update_spec_ctrl() helperWaiman Long1-0/+11
Add a new __update_spec_ctrl() helper which is a variant of update_spec_ctrl() that can be used in a noinstr function. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20230727184600.26768-2-longman@redhat.com
2023-10-07sched/core: Update stale comment in try_to_wake_up()Ingo Molnar1-1/+1
The following commit: 9b3c4ab3045e ("sched,rcu: Rework try_invoke_on_locked_down_task()") ... renamed try_invoke_on_locked_down_task() to task_call_func(), but forgot to update the comment in try_to_wake_up(). But it turns out that the smp_rmb() doesn't live in task_call_func() either, it was moved to __task_needs_rq_lock() in: 91dabf33ae5d ("sched: Fix race in task_call_func()") Fix that now. Also fix the s/smb/smp typo while at it. Reported-by: Zhang Qiao <zhangqiao22@huawei.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230731085759.11443-1-zhangqiao22@huawei.com
2023-10-07Merge branch 'sched/urgent' into sched/core, to pick up fixes and refresh ↵Ingo Molnar950-5075/+8547
the branch Signed-off-by: Ingo Molnar <mingo@kernel.org>
2023-10-05cpufreq: schedutil: Update next_freq when cpufreq_limits changeXuewen Yan1-1/+2
When cpufreq's policy is 'single', there is a scenario that will cause sg_policy's next_freq to be unable to update. When the CPU's util is always max, the cpufreq will be max, and then if we change the policy's scaling_max_freq to be a lower freq, indeed, the sg_policy's next_freq need change to be the lower freq, however, because the cpu_is_busy, the next_freq would keep the max_freq. For example: The cpu7 is a single CPU: unisoc:/sys/devices/system/cpu/cpufreq/policy7 # while true;do done& [1] 4737 unisoc:/sys/devices/system/cpu/cpufreq/policy7 # taskset -p 80 4737 pid 4737's current affinity mask: ff pid 4737's new affinity mask: 80 unisoc:/sys/devices/system/cpu/cpufreq/policy7 # cat scaling_max_freq 2301000 unisoc:/sys/devices/system/cpu/cpufreq/policy7 # cat scaling_cur_freq 2301000 unisoc:/sys/devices/system/cpu/cpufreq/policy7 # echo 2171000 > scaling_max_freq unisoc:/sys/devices/system/cpu/cpufreq/policy7 # cat scaling_max_freq 2171000 At this time, the sg_policy's next_freq would stay at 2301000, which is wrong. To fix this, add a check for the ->need_freq_update flag. [ mingo: Clarified the changelog. ] Co-developed-by: Guohua Yan <guohua.yan@unisoc.com> Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com> Signed-off-by: Guohua Yan <guohua.yan@unisoc.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230719130527.8074-1-xuewen.yan@unisoc.com
2023-10-03sched/headers: Remove duplicate header inclusionsYu Liao2-2/+0
<linux/psi.h> and "autogroup.h" are included twice, remove the duplicate header inclusion. Signed-off-by: Yu Liao <liaoyu15@huawei.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230802021501.2511569-1-liaoyu15@huawei.com
2023-10-03sched/eevdf: Fix avg_vruntime()Peter Zijlstra1-1/+9
The expectation is that placing a task at avg_vruntime() makes it eligible. Turns out there is a corner case where this is not the case. Specifically, avg_vruntime() relies on the fact that integer division is a flooring function (eg. it discards the remainder). By this property the value returned is slightly left of the true average. However! when the average is a negative (relative to min_vruntime) the effect is flipped and it becomes a ceil, with the result that the returned value is just right of the average and thus not eligible. Fixes: af4cf40470c2 ("sched/fair: Add cfs_rq::avg_vruntime") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2023-10-03sched/eevdf: Also update slice on placementPeter Zijlstra1-2/+4
Tasks that never consume their full slice would not update their slice value. This means that tasks that are spawned before the sysctl scaling keep their original (UP) slice length. Fixes: 147f3efaa241 ("sched/fair: Implement an EEVDF-like scheduling policy") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230915124822.847197830@noisy.programming.kicks-ass.net
2023-10-02sched/headers: Move 'struct sched_param' out of uapi, to work around ↵Kir Kolyshkin2-5/+4
glibc/musl breakage Both glibc and musl define 'struct sched_param' in sched.h, while kernel has it in uapi/linux/sched/types.h, making it cumbersome to use sched_getattr(2) or sched_setattr(2) from userspace. For example, something like this: #include <sched.h> #include <linux/sched/types.h> struct sched_attr sa; will result in "error: redefinition of ‘struct sched_param’" (note the code doesn't need sched_param at all -- it needs struct sched_attr plus some stuff from sched.h). The situation is, glibc is not going to provide a wrapper for sched_{get,set}attr, thus the need to include linux/sched_types.h directly, which leads to the above problem. Thus, the userspace is left with a few sub-par choices when it wants to use e.g. sched_setattr(2), such as maintaining a copy of struct sched_attr definition, or using some other ugly tricks. OTOH, 'struct sched_param' is well known, defined in POSIX, and it won't be ever changed (as that would break backward compatibility). So, while 'struct sched_param' is indeed part of the kernel uapi, exposing it the way it's done now creates an issue, and hiding it (like this patch does) fixes that issue, hopefully without creating another one: common userspace software rely on libc headers, and as for "special" software (like libc), it looks like glibc and musl do not rely on kernel headers for 'struct sched_param' definition (but let's Cc their mailing lists in case it's otherwise). The alternative to this patch would be to move struct sched_attr to, say, linux/sched.h, or linux/sched/attr.h (the new file). Oh, and here is the previous attempt to fix the issue: https://lore.kernel.org/all/20200528135552.GA87103@google.com/ While I support Linus arguments, the issue is still here and needs to be fixed. [ mingo: Linus is right, this shouldn't be needed - but on the other hand I agree that this header is not really helpful to user-space as-is. So let's pretend that <uapi/linux/sched/types.h> is only about sched_attr, and call this commit a workaround for user-space breakage that it in reality is ... Also, remove the Fixes tag. ] Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20230808030357.1213829-1-kolyshkin@gmail.com
2023-10-02sched/rt/docs: Use 'real-time' instead of 'realtime'Cyril Hrubis1-17/+17
Standardize on a single variant. Signed-off-by: Cyril Hrubis <chrubis@suse.cz> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231002115553.3007-4-chrubis@suse.cz
2023-10-02sched/rt/docs: Clarify & fix sched_rt_* sysctl docsCyril Hrubis1-6/+8
- Describe explicitly that sched_rt_runtime_us is allocated from sched_rt_period_us and hence always less or equal to that value. - The limit for sched_rt_runtime_us is not INT_MAX-1, but rather it's limited by the value of sched_rt_period_us. If sched_rt_period_us is INT_MAX then sched_rt_runtime_us can be set to INT_MAX as well. Signed-off-by: Cyril Hrubis <chrubis@suse.cz> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231002115553.3007-3-chrubis@suse.cz
2023-10-02sched/rt: Disallow writing invalid values to sched_rt_period_usCyril Hrubis1-4/+5
The validation of the value written to sched_rt_period_us was broken because: - the sysclt_sched_rt_period is declared as unsigned int - parsed by proc_do_intvec() - the range is asserted after the value parsed by proc_do_intvec() Because of this negative values written to the file were written into a unsigned integer that were later on interpreted as large positive integers which did passed the check: if (sysclt_sched_rt_period <= 0) return EINVAL; This commit fixes the parsing by setting explicit range for both perid_us and runtime_us into the sched_rt_sysctls table and processes the values with proc_dointvec_minmax() instead. Alternatively if we wanted to use full range of unsigned int for the period value we would have to split the proc_handler and use proc_douintvec() for it however even the Documentation/scheduller/sched-rt-group.rst describes the range as 1 to INT_MAX. As far as I can tell the only problem this causes is that the sysctl file allows writing negative values which when read back may confuse userspace. There is also a LTP test being submitted for these sysctl files at: http://patchwork.ozlabs.org/project/ltp/patch/20230901144433.2526-1-chrubis@suse.cz/ Signed-off-by: Cyril Hrubis <chrubis@suse.cz> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231002115553.3007-2-chrubis@suse.cz
2023-10-01Linux 6.6-rc4Linus Torvalds1-1/+1
2023-10-01Merge tag 'kbuild-fixes-v6.6-2' of ↵Linus Torvalds7-15/+41
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Fix the module compression with xz so the in-kernel decompressor works - Document a kconfig idiom to express an optional dependency between modules - Make modpost, when W=1 is given, detect broken drivers that reference .exit.* sections - Remove unused code * tag 'kbuild-fixes-v6.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: remove stale code for 'source' symlink in packaging scripts modpost: Don't let "driver"s reference .exit.* vmlinux.lds.h: remove unused CPU_KEEP and CPU_DISCARD macros modpost: add missing else to the "of" check Documentation: kbuild: explain handling optional dependencies kbuild: Use CRC32 and a 1MiB dictionary for XZ compressed modules
2023-10-01Merge tag 'mm-hotfixes-stable-2023-10-01-08-34' of ↵Linus Torvalds38-169/+455
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain to issues which were introduced after 6.5" * tag 'mm-hotfixes-stable-2023-10-01-08-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: Crash: add lock to serialize crash hotplug handling selftests/mm: fix awk usage in charge_reserved_hugetlb.sh and hugetlb_reparenting_test.sh that may cause error mm: mempolicy: keep VMA walk if both MPOL_MF_STRICT and MPOL_MF_MOVE are specified mm/damon/vaddr-test: fix memory leak in damon_do_test_apply_three_regions() mm, memcg: reconsider kmem.limit_in_bytes deprecation mm: zswap: fix potential memory corruption on duplicate store arm64: hugetlb: fix set_huge_pte_at() to work with all swap entries mm: hugetlb: add huge page size param to set_huge_pte_at() maple_tree: add MAS_UNDERFLOW and MAS_OVERFLOW states maple_tree: add mas_is_active() to detect in-tree walks nilfs2: fix potential use after free in nilfs_gccache_submit_read_data() mm: abstract moving to the next PFN mm: report success more often from filemap_map_folio_range() fs: binfmt_elf_efpic: fix personality for ELF-FDPIC
2023-10-01Merge tag 'char-misc-6.6-rc4' of ↵Linus Torvalds6-212/+102
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull misc driver fix from Greg KH: "Here is a single, much requested, fix for a set of misc drivers to resolve a much reported regression in the -rc series that has also propagated back to the stable releases. Sorry for the delay, lots of conference travel for a few weeks put me very far behind in patch wrangling. It has been reported by many to resolve the reported problem, and has been in linux-next with no reported issues" * tag 'char-misc-6.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: misc: rtsx: Fix some platforms can not boot and move the l1ss judgment to probe
2023-10-01Merge tag 'tty-6.6-rc4' of ↵Linus Torvalds2-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver fixes from Greg KH: "Here are two tty/serial driver fixes for 6.6-rc4 that resolve some reported regressions: - revert a n_gsm change that ended up causing problems - 8250_port fix for irq data both have been in linux-next for over a week with no reported problems" * tag 'tty-6.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: Revert "tty: n_gsm: fix UAF in gsm_cleanup_mux" serial: 8250_port: Check IRQ data before use
2023-10-01Merge tag 'x86-urgent-2023-10-01' of ↵Linus Torvalds3-7/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes: a kerneldoc build warning fix, add SRSO mitigation for AMD-derived Hygon processors, and fix a SGX kernel crash in the page fault handler that can trigger when ksgxd races to reclaim the SECS special page, by making the SECS page unswappable" * tag 'x86-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race x86/srso: Add SRSO mitigation for Hygon processors x86/kgdb: Fix a kerneldoc warning when build with W=1
2023-10-01Merge tag 'timers-urgent-2023-10-01' of ↵Linus Torvalds1-1/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Ingo Molnar: "Fix a spurious kernel warning during CPU hotplug events that may trigger when timer/hrtimer softirqs are pending, which are otherwise hotplug-safe and don't merit a warning" * tag 'timers-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers: Tag (hr)timer softirq as hotplug safe
2023-10-01Merge tag 'sched-urgent-2023-10-01' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "Fix a RT tasks related lockup/live-lock during CPU offlining" * tag 'sched-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/rt: Fix live lock between select_fallback_rq() and RT push
2023-10-01Merge tag 'perf-urgent-2023-10-01' of ↵Linus Torvalds1-7/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf event fixes from Ingo Molnar: "Misc fixes: work around an AMD microcode bug on certain models, and fix kexec kernel PMI handlers on AMD systems that get loaded on older kernels that have an unexpected register state" * tag 'perf-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/amd: Do not WARN() on every IRQ perf/x86/amd/core: Fix overflow reset on hotplug
2023-10-01kbuild: remove stale code for 'source' symlink in packaging scriptsMasahiro Yamada2-4/+0
Since commit d8131c2965d5 ("kbuild: remove $(MODLIB)/source symlink"), modules_install does not create the 'source' symlink. Remove the stale code from builddeb and kernel.spec. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-10-01modpost: Don't let "driver"s reference .exit.*Uwe Kleine-König1-2/+13
Drivers must not reference functions marked with __exit as these likely are not available when the code is built-in. There are few creative offenders uncovered for example in ARCH=amd64 allmodconfig builds. So only trigger the section mismatch warning for W=1 builds. The dual rule that drivers must not reference .init.* is implemented since commit 0db252452378 ("modpost: don't allow *driver to reference .init.*") which however missed that .exit.* should be handled in the same way. Thanks to Masahiro Yamada and Arnd Bergmann who gave valuable hints to find this improvement. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-10-01vmlinux.lds.h: remove unused CPU_KEEP and CPU_DISCARD macrosMasahiro Yamada1-7/+0
Remove the left-over of commit e24f6628811e ("modpost: remove all traces of cpuinit/cpuexit sections"). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2023-10-01modpost: add missing else to the "of" checkMauricio Faria de Oliveira1-1/+1
Without this 'else' statement, an "usb" name goes into two handlers: the first/previous 'if' statement _AND_ the for-loop over 'devtable', but the latter is useless as it has no 'usb' device_id entry anyway. Tested with allmodconfig before/after patch; no changes to *.mod.c: git checkout v6.6-rc3 make -j$(nproc) allmodconfig make -j$(nproc) olddefconfig make -j$(nproc) find . -name '*.mod.c' | cpio -pd /tmp/before # apply patch make -j$(nproc) find . -name '*.mod.c' | cpio -pd /tmp/after diff -r /tmp/before/ /tmp/after/ # no difference Fixes: acbef7b76629 ("modpost: fix module autoloading for OF devices with generic compatible property") Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-09-30Merge tag 'soc-fixes-6.6' of ↵Linus Torvalds29-90/+179
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM SoC fixes from Arnd Bergmann: "These are the latest bug fixes that have come up in the soc tree. Most of these are fairly minor. Most notably, the majority of changes this time are not for dts files as usual. - Updates to the addresses of the broadcom and aspeed entries in the MAINTAINERS file. - Defconfig updates to address a regression on samsung and a build warning from an unknown Kconfig symbol - Build fixes for the StrongARM and Uniphier platforms - Code fixes for SCMI and FF-A firmware drivers, both of which had a simple bug that resulted in invalid data, and a lesser fix for the optee firmware driver - Multiple fixes for the recently added loongson/loongarch "guts" soc driver - Devicetree fixes for RISC-V on the startfive platform, addressing issues with NOR flash, usb and uart. - Multiple fixes for NXP i.MX8/i.MX9 dts files, fixing problems with clock, gpio, hdmi settings and the Makefile - Bug fixes for i.MX firmware code and the OCOTP soc driver - Multiple fixes for the TI sysc bus driver - Minor dts updates for TI omap dts files, to address boot time warnings and errors" * tag 'soc-fixes-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (35 commits) MAINTAINERS: Fix Florian Fainelli's email address arm64: defconfig: enable syscon-poweroff driver ARM: locomo: fix locomolcd_power declaration soc: loongson: loongson2_guts: Remove unneeded semicolon soc: loongson: loongson2_guts: Convert to devm_platform_ioremap_resource() soc: loongson: loongson_pm2: Populate children syscon nodes dt-bindings: soc: loongson,ls2k-pmc: Allow syscon-reboot/syscon-poweroff as child soc: loongson: loongson_pm2: Drop useless of_device_id compatible dt-bindings: soc: loongson,ls2k-pmc: Use fallbacks for ls2k-pmc compatible soc: loongson: loongson_pm2: Add dependency for INPUT arm64: defconfig: remove CONFIG_COMMON_CLK_NPCM8XX=y ARM: uniphier: fix cache kernel-doc warnings MAINTAINERS: aspeed: Update Andrew's email address MAINTAINERS: aspeed: Update git tree URL firmware: arm_ffa: Don't set the memory region attributes for MEM_LEND arm64: dts: imx: Add imx8mm-prt8mm.dtb to build arm64: dts: imx8mm-evk: Fix hdmi@3d node soc: imx8m: Enable OCOTP clock for imx8mm before reading registers arm64: dts: imx8mp-beacon-kit: Fix audio_pll2 clock arm64: dts: imx8mp: Fix SDMA2/3 clocks ...
2023-09-30Merge tag 'trace-v6.6-rc3' of ↵Linus Torvalds4-8/+56
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Make sure 32-bit applications using user events have aligned access when running on a 64-bit kernel. - Add cond_resched in the loop that handles converting enums in print_fmt string is trace events. - Fix premature wake ups of polling processes in the tracing ring buffer. When a task polls waiting for a percentage of the ring buffer to be filled, the writer still will wake it up at every event. Add the polling's percentage to the "shortest_full" list to tell the writer when to wake it up. - For eventfs dir lookups on dynamic events, an event system's only event could be removed, leaving its dentry with no children. This is totally legitimate. But in eventfs_release() it must not access the children array, as it is only allocated when the dentry has children. * tag 'trace-v6.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: eventfs: Test for dentries array allocated in eventfs_release() tracing/user_events: Align set_bit() address for all archs tracing: relax trace_event_eval_update() execution with cond_resched() ring-buffer: Update "shortest_full" in polling
2023-09-30eventfs: Test for dentries array allocated in eventfs_release()Steven Rostedt (Google)1-1/+1
The dcache_dir_open_wrapper() could be called when a dynamic event is being deleted leaving a dentry with no children. In this case the dlist->dentries array will never be allocated. This needs to be checked for in eventfs_release(), otherwise it will trigger a NULL pointer dereference. Link: https://lore.kernel.org/linux-trace-kernel/20230930090106.1c3164e9@rorschach.local.home Cc: Mark Rutland <mark.rutland@arm.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Fixes: ef36b4f92868 ("eventfs: Remember what dentries were created on dir open") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30tracing/user_events: Align set_bit() address for all archsBeau Belgrave1-7/+51
All architectures should use a long aligned address passed to set_bit(). User processes can pass either a 32-bit or 64-bit sized value to be updated when tracing is enabled when on a 64-bit kernel. Both cases are ensured to be naturally aligned, however, that is not enough. The address must be long aligned without affecting checks on the value within the user process which require different adjustments for the bit for little and big endian CPUs. Add a compat flag to user_event_enabler that indicates when a 32-bit value is being used on a 64-bit kernel. Long align addresses and correct the bit to be used by set_bit() to account for this alignment. Ensure compat flags are copied during forks and used during deletion clears. Link: https://lore.kernel.org/linux-trace-kernel/20230925230829.341-2-beaub@linux.microsoft.com Link: https://lore.kernel.org/linux-trace-kernel/20230914131102.179100-1-cleger@rivosinc.com/ Cc: stable@vger.kernel.org Fixes: 7235759084a4 ("tracing/user_events: Use remote writes for event enablement") Reported-by: Clément Léger <cleger@rivosinc.com> Suggested-by: Clément Léger <cleger@rivosinc.com> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30tracing: relax trace_event_eval_update() execution with cond_resched()Clément Léger1-0/+1
When kernel is compiled without preemption, the eval_map_work_func() (which calls trace_event_eval_update()) will not be preempted up to its complete execution. This can actually cause a problem since if another CPU call stop_machine(), the call will have to wait for the eval_map_work_func() function to finish executing in the workqueue before being able to be scheduled. This problem was observe on a SMP system at boot time, when the CPU calling the initcalls executed clocksource_done_booting() which in the end calls stop_machine(). We observed a 1 second delay because one CPU was executing eval_map_work_func() and was not preempted by the stop_machine() task. Adding a call to cond_resched() in trace_event_eval_update() allows other tasks to be executed and thus continue working asynchronously like before without blocking any pending task at boot time. Link: https://lore.kernel.org/linux-trace-kernel/20230929191637.416931-1-cleger@rivosinc.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Clément Léger <cleger@rivosinc.com> Tested-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30ring-buffer: Update "shortest_full" in pollingSteven Rostedt (Google)1-0/+3
It was discovered that the ring buffer polling was incorrectly stating that read would not block, but that's because polling did not take into account that reads will block if the "buffer-percent" was set. Instead, the ring buffer polling would say reads would not block if there was any data in the ring buffer. This was incorrect behavior from a user space point of view. This was fixed by commit 42fb0a1e84ff by having the polling code check if the ring buffer had more data than what the user specified "buffer percent" had. The problem now is that the polling code did not register itself to the writer that it wanted to wait for a specific "full" value of the ring buffer. The result was that the writer would wake the polling waiter whenever there was a new event. The polling waiter would then wake up, see that there's not enough data in the ring buffer to notify user space and then go back to sleep. The next event would wake it up again. Before the polling fix was added, the code would wake up around 100 times for a hackbench 30 benchmark. After the "fix", due to the constant waking of the writer, it would wake up over 11,0000 times! It would never leave the kernel, so the user space behavior was still "correct", but this definitely is not the desired effect. To fix this, have the polling code add what it's waiting for to the "shortest_full" variable, to tell the writer not to wake it up if the buffer is not as full as it expects to be. Note, after this fix, it appears that the waiter is now woken up around 2x the times it was before (~200). This is a tremendous improvement from the 11,000 times, but I will need to spend some time to see why polling is more aggressive in its wakeups than the read blocking code. Link: https://lore.kernel.org/linux-trace-kernel/20230929180113.01c2cae3@rorschach.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Fixes: 42fb0a1e84ff ("tracing/ring-buffer: Have polling block on watermark") Reported-by: Julia Lawall <julia.lawall@inria.fr> Tested-by: Julia Lawall <julia.lawall@inria.fr> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30Merge tag 'dma-mapping-6.6-2023-09-30' of ↵Linus Torvalds2-16/+38
git://git.infradead.org/users/hch/dma-mapping Pull dma-mapping fixes from Christoph Hellwig: - fix the narea calculation in swiotlb initialization (Ross Lagerwall) - fix the check whether a device has used swiotlb (Petr Tesarik) * tag 'dma-mapping-6.6-2023-09-30' of git://git.infradead.org/users/hch/dma-mapping: swiotlb: fix the check whether a device has used software IO TLB swiotlb: use the calculated number of areas
2023-09-30Merge tag 'iomap-6.6-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds2-2/+11
Pull iomap fixes from Darrick Wong: - Handle a race between writing and shrinking block devices by returning EIO - Fix a typo in a comment * tag 'iomap-6.6-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: iomap: Spelling s/preceeding/preceding/g iomap: add a workaround for racy i_size updates on block devices