- 05 Jun, 2023 13 commits
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Peter Zijlstra authored
Currently hv_read_tsc_page_tsc() (ab)uses the (valid) time value of U64_MAX as an error return. This breaks the clean wrap-around of the clock. Modify the function signature to return a boolean state and provide another u64 pointer to store the actual time on success. This obviates the need to steal one time value and restores the full counter width. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.775630881@infradead.org
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Peter Zijlstra authored
Because of how the virtual clocks use U64_MAX as an exception value instead of a valid time, the clocks can no longer be assumed to wrap cleanly. This is then compounded by arch_vdso_cycles_ok() rejecting everything with the MSB/Sign-bit set. Therefore, the effective mask becomes S64_MAX, and the comment with vdso_calc_delta() that states the mask is U64_MAX and isn't optimized out is just plain silly. Now, the code has a negative filter -- to deal with TSC wobbles: if (cycles > last) which is just plain wrong, because it should've been written as: if ((s64)(cycles - last) > 0) to take wrapping into account, but per all the above, we don't actually wrap on u64 anymore. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.704767397@infradead.org
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Peter Zijlstra authored
In order to prevent the following complaint from happening, always inline the u128 variant of mul_u64_u64_shr() -- which is what x86_64 will use. vmlinux.o: warning: objtool: read_hv_sched_clock_tsc+0x5a: call to mul_u64_u64_shr.constprop.0() leaves .noinstr.text section It should compile into something like: asm("mul %[mul];" "shrd %rdx, %rax, %cl" : "+&a" (a) : "c" shift, [mul] "r" (mul) : "d"); Which is silly not to inline, but it happens. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.637420396@infradead.org
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Peter Zijlstra authored
With the intent to provide local_clock_noinstr(), a variant of local_clock() that's safe to be called from noinstr code (with the assumption that any such code will already be non-preemptible), prepare for things by providing a noinstr sched_clock_noinstr() function. Specifically, preempt_enable_*() calls out to schedule(), which upsets noinstr validation efforts. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.570170436@infradead.org
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Peter Zijlstra authored
With the intent to provide local_clock_noinstr(), a variant of local_clock() that's safe to be called from noinstr code (with the assumption that any such code will already be non-preemptible), prepare for things by providing a noinstr sched_clock_read() function. Specifically, preempt_enable_*() calls out to schedule(), which upsets noinstr validation efforts. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.502547082@infradead.org
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Peter Zijlstra authored
With the intent to provide local_clock_noinstr(), a variant of local_clock() that's safe to be called from noinstr code (with the assumption that any such code will already be non-preemptible), prepare for things by providing a noinstr sched_clock_read() function. Specifically, preempt_enable_*() calls out to schedule(), which upsets noinstr validation efforts. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.435618812@infradead.org
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Peter Zijlstra authored
The next patch will want to use __raw_readl() from a noinstr section and as such that needs to be marked __always_inline to avoid the compiler being a silly bugger. Turns out it already is, but its siblings are not. Finish the work started in commit e43f1331 ("arm64: Ask the compiler to __always_inline functions used by KVM at HYP") for consistenies sake. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <vschneid@redhat.com> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.368919762@infradead.org
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Peter Zijlstra authored
With the intent to provide local_clock_noinstr(), a variant of local_clock() that's safe to be called from noinstr code (with the assumption that any such code will already be non-preemptible), prepare for things by providing a noinstr sched_clock_noinstr() function. Specifically, preempt_enable_*() calls out to schedule(), which upsets noinstr validation efforts. As such, pull out the preempt_{dis,en}able_notrace() requirements from the sched_clock_read() implementations by explicitly providing it in the sched_clock() function. This further requires said sched_clock_read() functions to be noinstr themselves, for ARCH_WANTS_NO_INSTR users. See the next few patches. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.302350330@infradead.org
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Peter Zijlstra authored
The read side of seqcount_latch consists of: do { seq = raw_read_seqcount_latch(&latch->seq); ... } while (read_seqcount_latch_retry(&latch->seq, seq)); which is asymmetric in the raw_ department, and sure enough, read_seqcount_latch_retry() includes (explicit) instrumentation where raw_read_seqcount_latch() does not. This inconsistency becomes a problem when trying to use it from noinstr code. As such, fix it by renaming and re-implementing raw_read_seqcount_latch_retry() without the instrumentation. Specifically the instrumentation in question is kcsan_atomic_next(0) in do___read_seqcount_retry(). Loosing this annotation is not a problem because raw_read_seqcount_latch() does not pass through kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.233598176@infradead.org
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Peter Zijlstra authored
Instead of having a number of fixed topologies to pick from; build one on the fly. This is both simpler now and simpler to extend in the future. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230601153522.GB559993%40hirez.programming.kicks-ass.net
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Peter Zijlstra authored
With the introduction of task_struct::saved_state in commit 5f220be2 ("sched/wakeup: Prepare for RT sleeping spin/rwlocks") matching the task state has gotten more complicated. That same commit changed try_to_wake_up() to consider both states, but wait_task_inactive() has been neglected. Sebastian noted that the wait_task_inactive() usage in ptrace_check_attach() can misbehave when ptrace_stop() is blocked on the tasklist_lock after it sets TASK_TRACED. Therefore extract a common helper from ttwu_state_match() and use that to teach wait_task_inactive() about the PREEMPT_RT locks. Originally-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lkml.kernel.org/r/20230601091234.GW83892@hirez.programming.kicks-ass.net
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Peter Zijlstra authored
While modifying wait_task_inactive() for PREEMPT_RT; the build robot noted that UP got broken. This led to audit and consideration of the UP implementation of wait_task_inactive(). It looks like the UP implementation is also broken for PREEMPT; consider task_current_syscall() getting preempted between the two calls to wait_task_inactive(). Therefore move the wait_task_inactive() implementation out of CONFIG_SMP and unconditionally use it. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230602103731.GA630648%40hirez.programming.kicks-ass.net
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Yicong Yang authored
We've run into the case that the balancer tries to balance a migration disabled task and trigger the warning in set_task_cpu() like below: ------------[ cut here ]------------ WARNING: CPU: 7 PID: 0 at kernel/sched/core.c:3115 set_task_cpu+0x188/0x240 Modules linked in: hclgevf xt_CHECKSUM ipt_REJECT nf_reject_ipv4 <...snip> CPU: 7 PID: 0 Comm: swapper/7 Kdump: loaded Tainted: G O 6.1.0-rc4+ #1 Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V5.B221.01 12/09/2021 pstate: 604000c9 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : set_task_cpu+0x188/0x240 lr : load_balance+0x5d0/0xc60 sp : ffff80000803bc70 x29: ffff80000803bc70 x28: ffff004089e190e8 x27: ffff004089e19040 x26: ffff007effcabc38 x25: 0000000000000000 x24: 0000000000000001 x23: ffff80000803be84 x22: 000000000000000c x21: ffffb093e79e2a78 x20: 000000000000000c x19: ffff004089e19040 x18: 0000000000000000 x17: 0000000000001fad x16: 0000000000000030 x15: 0000000000000000 x14: 0000000000000003 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000001 x10: 0000000000000400 x9 : ffffb093e4cee530 x8 : 00000000fffffffe x7 : 0000000000ce168a x6 : 000000000000013e x5 : 00000000ffffffe1 x4 : 0000000000000001 x3 : 0000000000000b2a x2 : 0000000000000b2a x1 : ffffb093e6d6c510 x0 : 0000000000000001 Call trace: set_task_cpu+0x188/0x240 load_balance+0x5d0/0xc60 rebalance_domains+0x26c/0x380 _nohz_idle_balance.isra.0+0x1e0/0x370 run_rebalance_domains+0x6c/0x80 __do_softirq+0x128/0x3d8 ____do_softirq+0x18/0x24 call_on_irq_stack+0x2c/0x38 do_softirq_own_stack+0x24/0x3c __irq_exit_rcu+0xcc/0xf4 irq_exit_rcu+0x18/0x24 el1_interrupt+0x4c/0xe4 el1h_64_irq_handler+0x18/0x2c el1h_64_irq+0x74/0x78 arch_cpu_idle+0x18/0x4c default_idle_call+0x58/0x194 do_idle+0x244/0x2b0 cpu_startup_entry+0x30/0x3c secondary_start_kernel+0x14c/0x190 __secondary_switched+0xb0/0xb4 ---[ end trace 0000000000000000 ]--- Further investigation shows that the warning is superfluous, the migration disabled task is just going to be migrated to its current running CPU. This is because that on load balance if the dst_cpu is not allowed by the task, we'll re-select a new_dst_cpu as a candidate. If no task can be balanced to dst_cpu we'll try to balance the task to the new_dst_cpu instead. In this case when the migration disabled task is not on CPU it only allows to run on its current CPU, load balance will select its current CPU as new_dst_cpu and later triggers the warning above. The new_dst_cpu is chosen from the env->dst_grpmask. Currently it contains CPUs in sched_group_span() and if we have overlapped groups it's possible to run into this case. This patch makes env->dst_grpmask of group_balance_mask() which exclude any CPUs from the busiest group and solve the issue. For balancing in a domain with no overlapped groups the behaviour keeps same as before. Suggested-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20230530082507.10444-1-yangyicong@huawei.com
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- 30 May, 2023 6 commits
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Miaohe Lin authored
The default deadline bandwidth control structure has been removed since commit eb77cf1c ("sched/deadline: Remove unused def_dl_bandwidth") leading to unused init_dl_bandwidth() and struct dl_bandwidth. Remove them to clean up the code. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20230524102514.407486-1-linmiaohe@huawei.com
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Arnd Bergmann authored
These four functions have a normal definition for CONFIG_FAIR_GROUP_SCHED, and empty one that is only referenced when FAIR_GROUP_SCHED is disabled but CGROUP_SCHED is still enabled. If both are turned off, the functions are still defined but the misisng prototype causes a W=1 warning: kernel/sched/fair.c:12544:6: error: no previous prototype for 'free_fair_sched_group' kernel/sched/fair.c:12546:5: error: no previous prototype for 'alloc_fair_sched_group' kernel/sched/fair.c:12553:6: error: no previous prototype for 'online_fair_sched_group' kernel/sched/fair.c:12555:6: error: no previous prototype for 'unregister_fair_sched_group' Move the alternatives into the header as static inline functions with the correct combination of #ifdef checks to avoid the warning without adding even more complexity. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20230522195021.3456768-6-arnd@kernel.org
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Arnd Bergmann authored
Having the prototype next to the caller but not visible to the callee causes a W=1 warning: kernel/sched/fair.c:11985:6: error: no previous prototype for 'task_vruntime_update' [-Werror=missing-prototypes] Move this to a header, as we do for all other function declarations. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20230522195021.3456768-5-arnd@kernel.org
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Arnd Bergmann authored
init_cfs_bandwidth() is only used when CONFIG_FAIR_GROUP_SCHED is enabled, and without this causes a W=1 warning for the missing prototype: kernel/sched/fair.c:6131:6: error: no previous prototype for 'init_cfs_bandwidth' The normal implementation is only defined for CONFIG_CFS_BANDWIDTH, so the stub exists when CFS_BANDWIDTH is disabled but FAIR_GROUP_SCHED is enabled. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20230522195021.3456768-4-arnd@kernel.org
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Arnd Bergmann authored
The schedule_user() function is used on powerpc and sparc architectures, but only ever called from assembler, so it has no prototype, causing a harmless W=1 warning: kernel/sched/core.c:6730:35: error: no previous prototype for 'schedule_user' [-Werror=missing-prototypes] Add a prototype in sched/sched.h to shut up the warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20230522195021.3456768-3-arnd@kernel.org
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Arnd Bergmann authored
This function is only used when CONFIG_SMP is enabled, without that there is no caller and no prototype: kernel/sched/fair.c:688:5: error: no previous prototype for 'sched_update_scaling' [-Werror=missing-prototypes Hide the definition in the same #ifdef check as the declaration. Fixes: 8a99b683 ("sched: Move SCHED_DEBUG sysctl to debugfs") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20230522195021.3456768-2-arnd@kernel.org
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- 20 May, 2023 1 commit
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Yang Yang authored
Psi_group's poll_min_period is determined by the minimum window size of psi_trigger when creating new triggers. While destroying a psi_trigger, there is no need to reset poll_min_period if the psi_trigger being destroyed did not have the minimum window size, since in this condition poll_min_period will remain the same as before. Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Suren Baghdasaryan <surenb@google.com> Link: https://lkml.kernel.org/r/20230514163338.834345-1-surenb@google.com
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- 08 May, 2023 15 commits
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晏艳(采苓) authored
Commit e6fe3f42 ("sched: Make multiple runqueue task counters 32-bit") changed the type for rq->nr_uninterruptible from "unsigned long" to "unsigned int", but left wrong cast print to /sys/kernel/debug/sched/debug and to the console. For example, nr_uninterruptible's value is fffffff7 with type "unsigned int", (long)nr_uninterruptible shows 4294967287 while (int)nr_uninterruptible prints -9. So using int cast fixes wrong printing. Signed-off-by: Yan Yan <yanyan.yan@antgroup.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230506074253.44526-1-yanyan.yan@antgroup.com
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Tim C Chen authored
When a degenerate cluster domain for core with SMT CPUs is removed, the SD_SHARE_CPUCAPACITY flag in the local child sched group was not propagated to the new parent. We need this flag to properly determine whether the local sched group is SMT. Set the flag in the local child sched group of the new parent sched domain. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Link: https://lkml.kernel.org/r/73cf0959eafa53c02e7ef6bf805d751d9190e55d.1683156492.git.tim.c.chen@linux.intel.com
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Suren Baghdasaryan authored
Current 500ms min window size for psi triggers limits polling interval to 50ms to prevent polling threads from using too much cpu bandwidth by polling too frequently. However the number of cgroups with triggers is unlimited, so this protection can be defeated by creating multiple cgroups with psi triggers (triggers in each cgroup are served by a single "psimon" kernel thread). Instead of limiting min polling period, which also limits the latency of psi events, it's better to limit psi trigger creation to authorized users only, like we do for system-wide psi triggers (/proc/pressure/* files can be written only by processes with CAP_SYS_RESOURCE capability). This also makes access rules for cgroup psi files consistent with system-wide ones. Add a CAP_SYS_RESOURCE capability check for cgroup psi file writers and remove the psi window min size limitation. Suggested-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/all/cover.1676067791.git.quic_sudaraja@quicinc.com/
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Chen Yu authored
Intel Meteor Lake hybrid processors have cores in two separate dies. The cores in one of the dies have higher maximum frequency. Use the SD_ASYM_ PACKING flag to give higher priority to the die with CPUs of higher maximum frequency. Suggested-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230406203148.19182-13-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
X86 does not have the SD_ASYM_PACKING flag in the SMT domain. The scheduler knows how to handle SMT and non-SMT cores of different priority. There is no reason for SMT siblings of a core to have different priorities. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Len Brown <len.brown@intel.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-12-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
There is no difference between any of the SMT siblings of a physical core. Do not do asym_packing load balancing at this level. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-11-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
Only x86 and Power7 use ASYM_PACKING. They use it differently. Power7 has cores of equal priority, but the SMT siblings of a core have different priorities. Parent scheduling domains do not need (nor have) the ASYM_PACKING flag. SHARED_CHILD is not needed. Using SHARED_PARENT would cause the topology debug code to complain. X86 has cores of different priority, but all the SMT siblings of the core have equal priority. It needs ASYM_PACKING at the MC level, but not at the SMT level (it also needs it at upper levels if they have scheduling groups of different priority). Removing ASYM_PACKING from the SMT domain causes the topology debug code to complain. Remove SHARED_CHILD for now. We still need a topology check that satisfies both architectures. Suggested-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-10-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
Do not assume that all the children of a scheduling domain have a given flag. Check whether it has the SDF_SHARED_CHILD meta flag. Suggested-by: Ionela Voinescu <ionela.voinescu@arm.com> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230406203148.19182-9-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
Now that find_busiest_group() triggers load balancing between a fully_ busy SMT2 core and an idle non-SMT core, it is no longer needed to force balancing via asym_packing. Use asym_packing only as intended: when there is high-priority CPU that is idle. After this change, the same logic apply to SMT and non-SMT local groups. It makes less sense having a separate function to deal specifically with SMT. Fold the logic in asym_smt_can_pull_tasks() into sched_asym(). Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-8-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
The prefer_sibling setting acts on the busiest group to move excess tasks to the local group. This should be done as per request of the child of the busiest group's sched domain, not the local group's. Using the flags of the child domain of the local group works fortuitously if both groups have child domains. There are cases, however, in which the busiest group's sched domain has child but the local group's does not. Consider, for instance a non-SMT core (or an SMT core with only one online sibling) doing load balance with an SMT core at the MC level. SD_PREFER_SIBLING of the busiest group's child domain will not be honored. We are left with a fully busy SMT core and an idle non-SMT core. Suggested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-7-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
When comparing two fully_busy scheduling groups, keep the current busiest group if it represents an SMT core. Tasks in such scheduling group share CPU resources and need more help than tasks in a non-SMT fully_busy group. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-6-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
Using asym_packing priorities within an SMT core is straightforward. Just follow the priorities that hardware indicates. When balancing load from an SMT core, also consider the idle state of its siblings. Priorities do not reflect that an SMT core divides its throughput among all its busy siblings. They only makes sense when exactly one sibling is busy. Indicate that active balance is needed if the destination CPU has lower priority than the source CPU but the latter has busy SMT siblings. Make find_busiest_queue() not skip higher-priority SMT cores with more than busy sibling. Suggested-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-5-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
Callers of asym_smt_can_pull_tasks() check the idle state of the destination CPU and its SMT siblings, if any. No extra checks are needed in such function. Since SMT cores divide capacity among its siblings, priorities only really make sense if only one sibling is active. This is true for SMT2, SMT4, SMT8, etc. Do not use asym_packing load balance for this case. Instead, let find_busiest_group() handle imbalances. When balancing non-SMT cores or at higher scheduling domains (e.g., between MC scheduling groups), continue using priorities. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Len Brown <len.brown@intel.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-4-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
When balancing load between cores, all the SMT siblings of the destination CPU, if any, must be idle. Otherwise, pulling new tasks degrades the throughput of the busy SMT siblings. The overall throughput of the system remains the same. When balancing load within an SMT core this consideration is not relevant. Follow the priorities that hardware indicates. Suggested-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-3-ricardo.neri-calderon@linux.intel.com
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Ricardo Neri authored
asym_packing needs this function to determine whether an SMT core is a suitable destination for load balancing. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230406203148.19182-2-ricardo.neri-calderon@linux.intel.com
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- 07 May, 2023 5 commits
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Linus Torvalds authored
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Linus Torvalds authored
Merge tag 'perf-tools-for-v6.4-3-2023-05-06' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux Pull perf tool updates from Arnaldo Carvalho de Melo: "Third version of perf tool updates, with the build problems with with using a 'vmlinux.h' generated from the main build fixed, and the bpf skeleton build disabled by default. Build: - Require libtraceevent to build, one can disable it using NO_LIBTRACEEVENT=1. It is required for tools like 'perf sched', 'perf kvm', 'perf trace', etc. libtraceevent is available in most distros so installing 'libtraceevent-devel' should be a one-time event to continue building perf as usual. Using NO_LIBTRACEEVENT=1 produces tooling that is functional and sufficient for lots of users not interested in those libtraceevent dependent features. - Allow Python support in 'perf script' when libtraceevent isn't linked, as not all features requires it, for instance Intel PT does not use tracepoints. - Error if the python interpreter needed for jevents to work isn't available and NO_JEVENTS=1 isn't set, preventing a build without support for JSON vendor events, which is a rare but possible condition. The two check error messages: $(error ERROR: No python interpreter needed for jevents generation. Install python or build with NO_JEVENTS=1.) $(error ERROR: Python interpreter needed for jevents generation too old (older than 3.6). Install a newer python or build with NO_JEVENTS=1.) - Make libbpf 1.0 the minimum required when building with out of tree, distro provided libbpf. - Use libsdtc++'s and LLVM's libcxx's __cxa_demangle, a portable C++ demangler, add 'perf test' entry for it. - Make binutils libraries opt in, as distros disable building with it due to licensing, they were used for C++ demangling, for instance. - Switch libpfm4 to opt-out rather than opt-in, if libpfm-devel (or equivalent) isn't installed, we'll just have a build warning: Makefile.config:1144: libpfm4 not found, disables libpfm4 support. Please install libpfm4-dev - Add a feature test for scandirat(), that is not implemented so far in musl and uclibc, disabling features that need it, such as scanning for tracepoints in /sys/kernel/tracing/events. perf BPF filters: - New feature where BPF can be used to filter samples, for instance: $ sudo ./perf record -e cycles --filter 'period > 1000' true $ sudo ./perf script perf-exec 2273949 546850.708501: 5029 cycles: ffffffff826f9e25 finish_wait+0x5 ([kernel.kallsyms]) perf-exec 2273949 546850.708508: 32409 cycles: ffffffff826f9e25 finish_wait+0x5 ([kernel.kallsyms]) perf-exec 2273949 546850.708526: 143369 cycles: ffffffff82b4cdbf xas_start+0x5f ([kernel.kallsyms]) perf-exec 2273949 546850.708600: 372650 cycles: ffffffff8286b8f7 __pagevec_lru_add+0x117 ([kernel.kallsyms]) perf-exec 2273949 546850.708791: 482953 cycles: ffffffff829190de __mod_memcg_lruvec_state+0x4e ([kernel.kallsyms]) true 2273949 546850.709036: 501985 cycles: ffffffff828add7c tlb_gather_mmu+0x4c ([kernel.kallsyms]) true 2273949 546850.709292: 503065 cycles: 7f2446d97c03 _dl_map_object_deps+0x973 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) - In addition to 'period' (PERF_SAMPLE_PERIOD), the other PERF_SAMPLE_ can be used for filtering, and also some other sample accessible values, from tools/perf/Documentation/perf-record.txt: Essentially the BPF filter expression is: <term> <operator> <value> (("," | "||") <term> <operator> <value>)* The <term> can be one of: ip, id, tid, pid, cpu, time, addr, period, txn, weight, phys_addr, code_pgsz, data_pgsz, weight1, weight2, weight3, ins_lat, retire_lat, p_stage_cyc, mem_op, mem_lvl, mem_snoop, mem_remote, mem_lock, mem_dtlb, mem_blk, mem_hops The <operator> can be one of: ==, !=, >, >=, <, <=, & The <value> can be one of: <number> (for any term) na, load, store, pfetch, exec (for mem_op) l1, l2, l3, l4, cxl, io, any_cache, lfb, ram, pmem (for mem_lvl) na, none, hit, miss, hitm, fwd, peer (for mem_snoop) remote (for mem_remote) na, locked (for mem_locked) na, l1_hit, l1_miss, l2_hit, l2_miss, any_hit, any_miss, walk, fault (for mem_dtlb) na, by_data, by_addr (for mem_blk) hops0, hops1, hops2, hops3 (for mem_hops) perf lock contention: - Show lock type with address. - Track and show mmap_lock, siglock and per-cpu rq_lock with address. This is done for mmap_lock by following the current->mm pointer: $ sudo ./perf lock con -abl -- sleep 10 contended total wait max wait avg wait address symbol ... 16344 312.30 ms 2.22 ms 19.11 us ffff8cc702595640 17686 310.08 ms 1.49 ms 17.53 us ffff8cc7025952c0 3 84.14 ms 45.79 ms 28.05 ms ffff8cc78114c478 mmap_lock 3557 76.80 ms 68.75 us 21.59 us ffff8cc77ca3af58 1 68.27 ms 68.27 ms 68.27 ms ffff8cda745dfd70 9 54.53 ms 7.96 ms 6.06 ms ffff8cc7642a48b8 mmap_lock 14629 44.01 ms 60.00 us 3.01 us ffff8cc7625f9ca0 3481 42.63 ms 140.71 us 12.24 us ffffffff937906ac vmap_area_lock 16194 38.73 ms 42.15 us 2.39 us ffff8cd397cbc560 11 38.44 ms 10.39 ms 3.49 ms ffff8ccd6d12fbb8 mmap_lock 1 5.43 ms 5.43 ms 5.43 ms ffff8cd70018f0d8 1674 5.38 ms 422.93 us 3.21 us ffffffff92e06080 tasklist_lock 581 4.51 ms 130.68 us 7.75 us ffff8cc9b1259058 5 3.52 ms 1.27 ms 703.23 us ffff8cc754510070 112 3.47 ms 56.47 us 31.02 us ffff8ccee38b3120 381 3.31 ms 73.44 us 8.69 us ffffffff93790690 purge_vmap_area_lock 255 3.19 ms 36.35 us 12.49 us ffff8d053ce30c80 - Update default map size to 16384. - Allocate single letter option -M for --map-nr-entries, as it is proving being frequently used. - Fix struct rq lock access for older kernels with BPF's CO-RE (Compile once, run everywhere). - Fix problems found with MSAn. perf report/top: - Add inline information when using --call-graph=fp or lbr, as was already done to the --call-graph=dwarf callchain mode. - Improve the 'srcfile' sort key performance by really using an optimization introduced in 6.2 for the 'srcline' sort key that avoids calling addr2line for comparision with each sample. perf sched: - Make 'perf sched latency/map/replay' to use "sched:sched_waking" instead of "sched:sched_waking", consistent with 'perf record' since d566a9c2 ("perf sched: Prefer sched_waking event when it exists"). perf ftrace: - Make system wide the default target for latency subcommand, run the following command then generate some network traffic and press control+C: # perf ftrace latency -T __kfree_skb ^C DURATION | COUNT | GRAPH | 0 - 1 us | 27 | ############# | 1 - 2 us | 22 | ########### | 2 - 4 us | 8 | #### | 4 - 8 us | 5 | ## | 8 - 16 us | 24 | ############ | 16 - 32 us | 2 | # | 32 - 64 us | 1 | | 64 - 128 us | 0 | | 128 - 256 us | 0 | | 256 - 512 us | 0 | | 512 - 1024 us | 0 | | 1 - 2 ms | 0 | | 2 - 4 ms | 0 | | 4 - 8 ms | 0 | | 8 - 16 ms | 0 | | 16 - 32 ms | 0 | | 32 - 64 ms | 0 | | 64 - 128 ms | 0 | | 128 - 256 ms | 0 | | 256 - 512 ms | 0 | | 512 - 1024 ms | 0 | | 1 - ... s | 0 | | # perf top: - Add --branch-history (LBR: Last Branch Record) option, just like already available for 'perf record'. - Fix segfault in thread__comm_len() where thread->comm was being used outside thread->comm_lock. perf annotate: - Allow configuring objdump and addr2line in ~/.perfconfig., so that you can use alternative binaries, such as llvm's. perf kvm: - Add TUI mode for 'perf kvm stat report'. Reference counting: - Add reference count checking infrastructure to check for use after free, done to the 'cpumap', 'namespaces', 'maps' and 'map' structs, more to come. To build with it use -DREFCNT_CHECKING=1 in the make command line to build tools/perf. Documented at: https://perf.wiki.kernel.org/index.php/Reference_Count_Checking - The above caught, for instance, fix, present in this series: - Fix maps use after put in 'perf test "Share thread maps"': 'maps' is copied from leader, but the leader is put on line 79 and then 'maps' is used to read the reference count below - so a use after put, with the put of maps happening within thread__put. Fixed by reversing the order of puts so that the leader is put last. - Also several fixes were made to places where reference counts were not being held. - Make this one of the tests in 'make -C tools/perf build-test' to regularly build test it and to make sure no direct access to the reference counted structs are made, doing that via accessors to check the validity of the struct pointer. ARM64: - Fix 'perf report' segfault when filtering coresight traces by sparse lists of CPUs. - Add support for 'simd' as a sort field for 'perf report', to show ARM's NEON SIMD's predicate flags: "partial" and "empty". arm64 vendor events: - Add N1 metrics. Intel vendor events: - Add graniterapids, grandridge and sierraforrest events. - Refresh events for: alderlake, aldernaken, broadwell, broadwellde, broadwellx, cascadelakx, haswell, haswellx, icelake, icelakex, jaketown, meteorlake, knightslanding, sandybridge, sapphirerapids, silvermont, skylake, tigerlake and westmereep-dp - Refresh metrics for alderlake-n, broadwell, broadwellde, broadwellx, haswell, haswellx, icelakex, ivybridge, ivytown and skylakex. perf stat: - Implement --topdown using JSON metrics. - Add TopdownL1 JSON metric as a default if present, but disable it for now for some Intel hybrid architectures, a series of patches addressing this is being reviewed and will be submitted for v6.5. - Use metrics for --smi-cost. - Update topdown documentation. Vendor events (JSON) infrastructure: - Add support for computing and printing metric threshold values. For instance, here is one found in thesapphirerapids json file: { "BriefDescription": "Percentage of cycles spent in System Management Interrupts.", "MetricExpr": "((msr@aperf@ - cycles) / msr@aperf@ if msr@smi@ > 0 else 0)", "MetricGroup": "smi", "MetricName": "smi_cycles", "MetricThreshold": "smi_cycles > 0.1", "ScaleUnit": "100%" }, - Test parsing metric thresholds with the fake PMU in 'perf test pmu-events'. - Support for printing metric thresholds in 'perf list'. - Add --metric-no-threshold option to 'perf stat'. - Add rand (reverse and) and has_pmem (optane memory) support to metrics. - Sort list of input files to avoid depending on the order from readdir() helping in obtaining reproducible builds. S/390: - Add common metrics: - CPI (cycles per instruction), prbstate (ratio of instructions executed in problem state compared to total number of instructions), l1mp (Level one instruction and data cache misses per 100 instructions). - Add cache metrics for z13, z14, z15 and z16. - Add metric for TLB and cache. ARM: - Add raw decoding for SPE (Statistical Profiling Extension) v1.3 MTE (Memory Tagging Extension) and MOPS (Memory Operations) load/store. Intel PT hardware tracing: - Add event type names UINTR (User interrupt delivered) and UIRET (Exiting from user interrupt routine), documented in table 32-50 "CFE Packet Type and Vector Fields Details" in the Intel Processor Trace chapter of The Intel SDM Volume 3 version 078. - Add support for new branch instructions ERETS and ERETU. - Fix CYC timestamps after standalone CBR ARM CoreSight hardware tracing: - Allow user to override timestamp and contextid settings. - Fix segfault in dso lookup. - Fix timeless decode mode detection. - Add separate decode paths for timeless and per-thread modes. auxtrace: - Fix address filter entire kernel size. Miscellaneous: - Fix use-after-free and unaligned bugs in the PLT handling routines. - Use zfree() to reduce chances of use after free. - Add missing 0x prefix for addresses printed in hexadecimal in 'perf probe'. - Suppress massive unsupported target platform errors in the unwind code. - Fix return incorrect build_id size in elf_read_build_id(). - Fix 'perf scripts intel-pt-events.py' IPC output for Python 2 . - Add missing new parameter in kfree_skb tracepoint to the python scripts using it. - Add 'perf bench syscall fork' benchmark. - Add support for printing PERF_MEM_LVLNUM_UNC (Uncached access) in 'perf mem'. - Fix wrong size expectation for perf test 'Setup struct perf_event_attr' caused by the patch adding perf_event_attr::config3. - Fix some spelling mistakes" * tag 'perf-tools-for-v6.4-3-2023-05-06' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (365 commits) Revert "perf build: Make BUILD_BPF_SKEL default, rename to NO_BPF_SKEL" Revert "perf build: Warn for BPF skeletons if endian mismatches" perf metrics: Fix SEGV with --for-each-cgroup perf bpf skels: Stop using vmlinux.h generated from BTF, use subset of used structs + CO-RE perf stat: Separate bperf from bpf_profiler perf test record+probe_libc_inet_pton: Fix call chain match on x86_64 perf test record+probe_libc_inet_pton: Fix call chain match on s390 perf tracepoint: Fix memory leak in is_valid_tracepoint() perf cs-etm: Add fix for coresight trace for any range of CPUs perf build: Fix unescaped # in perf build-test perf unwind: Suppress massive unsupported target platform errors perf script: Add new parameter in kfree_skb tracepoint to the python scripts using it perf script: Print raw ip instead of binary offset for callchain perf symbols: Fix return incorrect build_id size in elf_read_build_id() perf list: Modify the warning message about scandirat(3) perf list: Fix memory leaks in print_tracepoint_events() perf lock contention: Rework offset calculation with BPF CO-RE perf lock contention: Fix struct rq lock access perf stat: Disable TopdownL1 on hybrid perf stat: Avoid SEGV on counter->name ...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull debugobjects fix from Thomas Gleixner: "A single fix for debugobjects: The recent fix to ensure atomicity of lookup and allocation inadvertently broke the pool refill mechanism, so that debugobject OOMs now in certain situations. The reason is that the functions which got updated no longer invoke debug_objecs_init(), which is now the only place to care about refilling the tracking object pool. Restore the original behaviour by adding explicit refill opportunities to those places" * tag 'core-debugobjects-2023-05-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: debugobject: Ensure pool refill (again)
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds authored
Pull crypto fixes from Herbert Xu: - A long-standing bug in crypto_engine - A buggy but harmless check in the sun8i-ss driver - A regression in the CRYPTO_USER interface * tag 'v6.4-p2' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: api - Fix CRYPTO_USER checks for report function crypto: engine - fix crypto_queue backlog handling crypto: sun8i-ss - Fix a test in sun8i_ss_setup_ivs()
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git://git.samba.org/sfrench/cifs-2.6Linus Torvalds authored
Pull cifs fixes from Steve French: "smb3 client fixes, mostly DFS or reconnect related: - Two DFS connection sharing fixes - DFS refresh fix - Reconnect fix - Two potential use after free fixes - Also print prefix patch in mount debug msg - Two small cleanup fixes" * tag '6.4-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6: cifs: Remove unneeded semicolon cifs: fix sharing of DFS connections cifs: avoid potential races when handling multiple dfs tcons cifs: protect access of TCP_Server_Info::{origin,leaf}_fullpath cifs: fix potential race when tree connecting ipc cifs: fix potential use-after-free bugs in TCP_Server_Info::hostname cifs: print smb3_fs_context::source when mounting cifs: protect session status check in smb2_reconnect() SMB3.1.1: correct definition for app_instance_id create contexts
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