kernel/linux.git/include/linux/vtime.h, branch v6.6.132

sched/vtime: Move guest enter/exit vtime accounting to vtime.h

2021-05-05T20:54:11+00:00

Provide separate helpers for guest enter vtime accounting (in addition to the existing guest exit helpers), and move all vtime accounting helpers to vtime.h where the existing #ifdef infrastructure can be leveraged to better delineate the different types of accounting. This will also allow future cleanups via deduplication of context tracking code. Opportunstically delete the vtime_account_kernel() stub now that all callers are wrapped with CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y. No functional change intended. Signed-off-by: Sean Christopherson Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210505002735.1684165-6-seanjc@google.com

sched/vtime: Move vtime accounting external declarations above inlines

2021-05-05T20:54:11+00:00

Move the blob of external declarations (and their stubs) above the set of inline definitions (and their stubs) for vtime accounting. This will allow a future patch to bring in more inline definitions without also having to shuffle large chunks of code. No functional change intended. Signed-off-by: Sean Christopherson Signed-off-by: Thomas Gleixner Reviewed-by: Christian Borntraeger Link: https://lore.kernel.org/r/20210505002735.1684165-5-seanjc@google.com

irqtime: Move irqtime entry accounting after irq offset incrementation

2020-12-02T19:20:05+00:00

IRQ time entry is currently accounted before HARDIRQ_OFFSET or SOFTIRQ_OFFSET are incremented. This is convenient to decide to which index the cputime to account is dispatched. Unfortunately it prevents tick_irq_enter() from being called under HARDIRQ_OFFSET because tick_irq_enter() has to be called before the IRQ entry accounting due to the necessary clock catch up. As a result we don't benefit from appropriate lockdep coverage on tick_irq_enter(). To prepare for fixing this, move the IRQ entry cputime accounting after the preempt offset is incremented. This requires the cputime dispatch code to handle the extra offset. Signed-off-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20201202115732.27827-5-frederic@kernel.org

sched/vtime: Consolidate IRQ time accounting

2020-12-02T19:20:05+00:00

The 3 architectures implementing CONFIG_VIRT_CPU_ACCOUNTING_NATIVE all have their own version of irq time accounting that dispatch the cputime to the appropriate index: hardirq, softirq, system, idle, guest... from an all-in-one function. Instead of having these ad-hoc versions, move the cputime destination dispatch decision to the core code and leave only the actual per-index cputime accounting to the architecture. Signed-off-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201202115732.27827-4-frederic@kernel.org

context_tracking: Check static key on context_tracking_enabled_*cpu()

2019-10-29T09:01:16+00:00

guest_enter() doesn't call context_tracking_enabled() before calling context_tracking_enabled_this_cpu(). Therefore the guest code doesn't benefit from the static key on the fast path. Just make sure that context_tracking_enabled_*cpu() functions check the static key by themselves to propagate the optimization. Reported-by: Peter Zijlstra Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Jacek Anaszewski Cc: Linus Torvalds Cc: Pavel Machek Cc: Rafael J . Wysocki Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191016025700.31277-11-frederic@kernel.org Signed-off-by: Ingo Molnar

sched/vtime: Introduce vtime_accounting_enabled_cpu()

2019-10-29T09:01:15+00:00

This allows us to check if a remote CPU runs vtime accounting (ie: is nohz_full). We'll need that to reliably support reading kcpustat on nohz_full CPUs. Also simplify a bit the condition in the local flavoured function while at it. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Jacek Anaszewski Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191016025700.31277-10-frederic@kernel.org Signed-off-by: Ingo Molnar

sched/vtime: Rename vtime_accounting_cpu_enabled() to vtime_accounting_enabled_this_cpu()

2019-10-29T09:01:14+00:00

Standardize the naming on top of the vtime_accounting_enabled_*() base. Also make it clear we are checking the vtime state of the *current* CPU with this function. We'll need to add an API to check that state on remote CPUs as well, so we must disambiguate the naming. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Jacek Anaszewski Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191016025700.31277-9-frederic@kernel.org Signed-off-by: Ingo Molnar

context_tracking: Rename context_tracking_is_cpu_enabled() to context_tracking_enabled_this_cpu()

2019-10-29T09:01:12+00:00

Standardize the naming on top of the context_tracking_enabled_*() base. Also make it clear we are checking the context tracking state of the *current* CPU with this function. We'll need to add an API to check that state on remote CPUs as well, so we must disambiguate the naming. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Jacek Anaszewski Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191016025700.31277-7-frederic@kernel.org Signed-off-by: Ingo Molnar

context_tracking: Rename context_tracking_is_enabled() => context_tracking_enabled()

2019-10-29T09:01:12+00:00

Remove the superfluous "is" in the middle of the name. We want to standardize the naming so that it can be expanded through suffixes: context_tracking_enabled() context_tracking_enabled_cpu() context_tracking_enabled_this_cpu() Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Jacek Anaszewski Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191016025700.31277-6-frederic@kernel.org Signed-off-by: Ingo Molnar

sched/cputime: Spare a seqcount lock/unlock cycle on context switch

2019-10-09T10:39:26+00:00

On context switch we are locking the vtime seqcount of the scheduling-out task twice: * On vtime_task_switch_common(), when we flush the pending vtime through vtime_account_system() * On arch_vtime_task_switch() to reset the vtime state. This is pointless as these actions can be performed without the need to unlock/lock in the middle. The reason these steps are separated is to consolidate a very small amount of common code between CONFIG_VIRT_CPU_ACCOUNTING_GEN and CONFIG_VIRT_CPU_ACCOUNTING_NATIVE. Performance in this fast path is definitely a priority over artificial code factorization so split the task switch code between GEN and NATIVE and mutualize the parts than can run under a single seqcount locked block. As a side effect, vtime_account_idle() becomes included in the seqcount protection. This happens to be a welcome preparation in order to properly support kcpustat under vtime in the future and fetch CPUTIME_IDLE without race. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191003161745.28464-3-frederic@kernel.org Signed-off-by: Ingo Molnar