Typical cputime stats infrastructure relies on the timer tick and its periodic polling on the CPU to account the amount of time spent by the CPUs and the tasks per high level domains such as userspace, kernelspace, guest, ... Now we are preparing to implement full dynticks capability on Linux for Real Time and HPC users who want full CPU isolation. This feature requires a cputime accounting that doesn't depend on the timer tick. To implement it, this new cputime infrastructure plugs into kernel/user/guest boundaries to take snapshots of cputime and flush these to the stats when needed. This performs pretty much like CONFIG_VIRT_CPU_ACCOUNTING except that context location and cputime snaphots are synchronized between write and read side such that the latter can safely retrieve the pending tickless cputime of a task and add it to its latest cputime snapshot to return the correct result to the user. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAABAgAGBQJRBsKnAAoJEIUkVEdQjox3lMgP/2R6DU2f8PyGIao3hne4M3Pu L3q+mAG53b24Dy014KeW7gd8yv45fE7wp/rs8CGLte9VzbLkRCDSFQPgBuXVagRj tV5nfAuqD0wHTnA+HhBE3l3C2RKAPGIu79rBpnIR/QIPPl8Z3Dby8YgmxEQKDf8G j7MEBu2LthSuqEi2ZXemnO5r0oEnQAzAp4TTi/M38k0Fmt59nOGyjLnI+xHYCBMa 1pnz7j3jjR9NJExGu8iVvbo+jupuQngP8qmkLXHvYnj/TEJNwzO1hHVoSwOpjYpS 9ycl+T8IKQLbAkBywLtq3Mzde43xt/t8wYyGZ0oAV+Z7MIpz/9YIfDJwqQeqoNbD dAdbNjKMbsxCgmrnyqSagfMQg/r3CPZ4vf40TMCaN4gNUJC4Ie+E4kPRKRh59+PB Ukthmqujn0f40LAa+HXTUuzafd3b0s/ewH+8FuQ6LAG9b5+WnoN8JTJ5u6+ydokO ZleeOowuRZZEg+abQ8Sm2GRm/BzN29gi/npb//I+ZDXWv/+3yccgsiPjCRzCAAaO g1RmYryFSRUwHQbGNNypVWVuOLWvrBQ4jqbGO7BBuBByZMSHryKxR6mb+inH3qLE xIDM9SdSJisc292OzoFKwVZki4MaXaadJXJduVvqYlZQvXXs7eAa4wo3euhtVITD NLQO5OZXE4oIQmDFb0FV =1Tzp -----END PGP SIGNATURE----- Merge tag 'full-dynticks-cputime-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core Pull full-dynticks (user-space execution is undisturbed and receives no timer IRQs) preparation changes that convert the cputime accounting code to be full-dynticks ready, from Frederic Weisbecker: "This implements the cputime accounting on full dynticks CPUs. Typical cputime stats infrastructure relies on the timer tick and its periodic polling on the CPU to account the amount of time spent by the CPUs and the tasks per high level domains such as userspace, kernelspace, guest, ... Now we are preparing to implement full dynticks capability on Linux for Real Time and HPC users who want full CPU isolation. This feature requires a cputime accounting that doesn't depend on the timer tick. To implement it, this new cputime infrastructure plugs into kernel/user/guest boundaries to take snapshots of cputime and flush these to the stats when needed. This performs pretty much like CONFIG_VIRT_CPU_ACCOUNTING except that context location and cputime snaphots are synchronized between write and read side such that the latter can safely retrieve the pending tickless cputime of a task and add it to its latest cputime snapshot to return the correct result to the user." Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
820 lines
20 KiB
C
820 lines
20 KiB
C
#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/tsacct_kern.h>
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#include <linux/kernel_stat.h>
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#include <linux/static_key.h>
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#include <linux/context_tracking.h>
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#include "sched.h"
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#ifdef CONFIG_IRQ_TIME_ACCOUNTING
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/*
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* There are no locks covering percpu hardirq/softirq time.
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* They are only modified in vtime_account, on corresponding CPU
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* with interrupts disabled. So, writes are safe.
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* They are read and saved off onto struct rq in update_rq_clock().
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* This may result in other CPU reading this CPU's irq time and can
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* race with irq/vtime_account on this CPU. We would either get old
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* or new value with a side effect of accounting a slice of irq time to wrong
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* task when irq is in progress while we read rq->clock. That is a worthy
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* compromise in place of having locks on each irq in account_system_time.
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*/
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DEFINE_PER_CPU(u64, cpu_hardirq_time);
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DEFINE_PER_CPU(u64, cpu_softirq_time);
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static DEFINE_PER_CPU(u64, irq_start_time);
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static int sched_clock_irqtime;
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void enable_sched_clock_irqtime(void)
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{
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sched_clock_irqtime = 1;
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}
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void disable_sched_clock_irqtime(void)
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{
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sched_clock_irqtime = 0;
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}
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#ifndef CONFIG_64BIT
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DEFINE_PER_CPU(seqcount_t, irq_time_seq);
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#endif /* CONFIG_64BIT */
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/*
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* Called before incrementing preempt_count on {soft,}irq_enter
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* and before decrementing preempt_count on {soft,}irq_exit.
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*/
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void irqtime_account_irq(struct task_struct *curr)
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{
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unsigned long flags;
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s64 delta;
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int cpu;
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if (!sched_clock_irqtime)
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return;
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local_irq_save(flags);
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cpu = smp_processor_id();
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delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time);
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__this_cpu_add(irq_start_time, delta);
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irq_time_write_begin();
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/*
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* We do not account for softirq time from ksoftirqd here.
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* We want to continue accounting softirq time to ksoftirqd thread
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* in that case, so as not to confuse scheduler with a special task
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* that do not consume any time, but still wants to run.
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*/
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if (hardirq_count())
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__this_cpu_add(cpu_hardirq_time, delta);
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else if (in_serving_softirq() && curr != this_cpu_ksoftirqd())
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__this_cpu_add(cpu_softirq_time, delta);
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irq_time_write_end();
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local_irq_restore(flags);
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}
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EXPORT_SYMBOL_GPL(irqtime_account_irq);
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static int irqtime_account_hi_update(void)
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{
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u64 *cpustat = kcpustat_this_cpu->cpustat;
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unsigned long flags;
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u64 latest_ns;
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int ret = 0;
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local_irq_save(flags);
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latest_ns = this_cpu_read(cpu_hardirq_time);
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if (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_IRQ])
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ret = 1;
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local_irq_restore(flags);
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return ret;
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}
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static int irqtime_account_si_update(void)
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{
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u64 *cpustat = kcpustat_this_cpu->cpustat;
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unsigned long flags;
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u64 latest_ns;
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int ret = 0;
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local_irq_save(flags);
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latest_ns = this_cpu_read(cpu_softirq_time);
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if (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_SOFTIRQ])
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ret = 1;
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local_irq_restore(flags);
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return ret;
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}
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#else /* CONFIG_IRQ_TIME_ACCOUNTING */
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#define sched_clock_irqtime (0)
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#endif /* !CONFIG_IRQ_TIME_ACCOUNTING */
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static inline void task_group_account_field(struct task_struct *p, int index,
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u64 tmp)
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{
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#ifdef CONFIG_CGROUP_CPUACCT
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struct kernel_cpustat *kcpustat;
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struct cpuacct *ca;
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#endif
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/*
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* Since all updates are sure to touch the root cgroup, we
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* get ourselves ahead and touch it first. If the root cgroup
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* is the only cgroup, then nothing else should be necessary.
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*
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*/
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__get_cpu_var(kernel_cpustat).cpustat[index] += tmp;
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#ifdef CONFIG_CGROUP_CPUACCT
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if (unlikely(!cpuacct_subsys.active))
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return;
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rcu_read_lock();
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ca = task_ca(p);
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while (ca && (ca != &root_cpuacct)) {
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kcpustat = this_cpu_ptr(ca->cpustat);
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kcpustat->cpustat[index] += tmp;
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ca = parent_ca(ca);
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}
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rcu_read_unlock();
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#endif
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}
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/*
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* Account user cpu time to a process.
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* @p: the process that the cpu time gets accounted to
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* @cputime: the cpu time spent in user space since the last update
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* @cputime_scaled: cputime scaled by cpu frequency
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*/
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void account_user_time(struct task_struct *p, cputime_t cputime,
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cputime_t cputime_scaled)
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{
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int index;
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/* Add user time to process. */
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p->utime += cputime;
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p->utimescaled += cputime_scaled;
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account_group_user_time(p, cputime);
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index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
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/* Add user time to cpustat. */
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task_group_account_field(p, index, (__force u64) cputime);
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/* Account for user time used */
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acct_account_cputime(p);
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}
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/*
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* Account guest cpu time to a process.
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* @p: the process that the cpu time gets accounted to
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* @cputime: the cpu time spent in virtual machine since the last update
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* @cputime_scaled: cputime scaled by cpu frequency
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*/
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static void account_guest_time(struct task_struct *p, cputime_t cputime,
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cputime_t cputime_scaled)
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{
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u64 *cpustat = kcpustat_this_cpu->cpustat;
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/* Add guest time to process. */
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p->utime += cputime;
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p->utimescaled += cputime_scaled;
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account_group_user_time(p, cputime);
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p->gtime += cputime;
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/* Add guest time to cpustat. */
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if (TASK_NICE(p) > 0) {
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cpustat[CPUTIME_NICE] += (__force u64) cputime;
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cpustat[CPUTIME_GUEST_NICE] += (__force u64) cputime;
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} else {
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cpustat[CPUTIME_USER] += (__force u64) cputime;
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cpustat[CPUTIME_GUEST] += (__force u64) cputime;
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}
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}
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/*
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* Account system cpu time to a process and desired cpustat field
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* @p: the process that the cpu time gets accounted to
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* @cputime: the cpu time spent in kernel space since the last update
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* @cputime_scaled: cputime scaled by cpu frequency
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* @target_cputime64: pointer to cpustat field that has to be updated
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*/
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static inline
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void __account_system_time(struct task_struct *p, cputime_t cputime,
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cputime_t cputime_scaled, int index)
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{
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/* Add system time to process. */
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p->stime += cputime;
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p->stimescaled += cputime_scaled;
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account_group_system_time(p, cputime);
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/* Add system time to cpustat. */
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task_group_account_field(p, index, (__force u64) cputime);
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/* Account for system time used */
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acct_account_cputime(p);
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}
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/*
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* Account system cpu time to a process.
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* @p: the process that the cpu time gets accounted to
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* @hardirq_offset: the offset to subtract from hardirq_count()
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* @cputime: the cpu time spent in kernel space since the last update
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* @cputime_scaled: cputime scaled by cpu frequency
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*/
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void account_system_time(struct task_struct *p, int hardirq_offset,
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cputime_t cputime, cputime_t cputime_scaled)
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{
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int index;
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if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
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account_guest_time(p, cputime, cputime_scaled);
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return;
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}
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if (hardirq_count() - hardirq_offset)
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index = CPUTIME_IRQ;
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else if (in_serving_softirq())
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index = CPUTIME_SOFTIRQ;
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else
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index = CPUTIME_SYSTEM;
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__account_system_time(p, cputime, cputime_scaled, index);
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}
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/*
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* Account for involuntary wait time.
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* @cputime: the cpu time spent in involuntary wait
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*/
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void account_steal_time(cputime_t cputime)
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{
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u64 *cpustat = kcpustat_this_cpu->cpustat;
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cpustat[CPUTIME_STEAL] += (__force u64) cputime;
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}
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/*
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* Account for idle time.
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* @cputime: the cpu time spent in idle wait
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*/
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void account_idle_time(cputime_t cputime)
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{
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u64 *cpustat = kcpustat_this_cpu->cpustat;
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struct rq *rq = this_rq();
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if (atomic_read(&rq->nr_iowait) > 0)
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cpustat[CPUTIME_IOWAIT] += (__force u64) cputime;
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else
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cpustat[CPUTIME_IDLE] += (__force u64) cputime;
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}
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static __always_inline bool steal_account_process_tick(void)
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{
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#ifdef CONFIG_PARAVIRT
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if (static_key_false(¶virt_steal_enabled)) {
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u64 steal, st = 0;
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steal = paravirt_steal_clock(smp_processor_id());
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steal -= this_rq()->prev_steal_time;
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st = steal_ticks(steal);
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this_rq()->prev_steal_time += st * TICK_NSEC;
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account_steal_time(st);
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return st;
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}
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#endif
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return false;
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}
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/*
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* Accumulate raw cputime values of dead tasks (sig->[us]time) and live
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* tasks (sum on group iteration) belonging to @tsk's group.
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*/
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void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
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{
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struct signal_struct *sig = tsk->signal;
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cputime_t utime, stime;
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struct task_struct *t;
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times->utime = sig->utime;
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times->stime = sig->stime;
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times->sum_exec_runtime = sig->sum_sched_runtime;
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rcu_read_lock();
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/* make sure we can trust tsk->thread_group list */
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if (!likely(pid_alive(tsk)))
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goto out;
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t = tsk;
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do {
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task_cputime(tsk, &utime, &stime);
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times->utime += utime;
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times->stime += stime;
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times->sum_exec_runtime += task_sched_runtime(t);
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} while_each_thread(tsk, t);
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out:
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rcu_read_unlock();
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}
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#ifdef CONFIG_IRQ_TIME_ACCOUNTING
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/*
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* Account a tick to a process and cpustat
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* @p: the process that the cpu time gets accounted to
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* @user_tick: is the tick from userspace
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* @rq: the pointer to rq
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*
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* Tick demultiplexing follows the order
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* - pending hardirq update
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* - pending softirq update
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* - user_time
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* - idle_time
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* - system time
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* - check for guest_time
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* - else account as system_time
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*
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* Check for hardirq is done both for system and user time as there is
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* no timer going off while we are on hardirq and hence we may never get an
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* opportunity to update it solely in system time.
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* p->stime and friends are only updated on system time and not on irq
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* softirq as those do not count in task exec_runtime any more.
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*/
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static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
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struct rq *rq)
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{
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cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
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u64 *cpustat = kcpustat_this_cpu->cpustat;
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if (steal_account_process_tick())
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return;
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if (irqtime_account_hi_update()) {
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cpustat[CPUTIME_IRQ] += (__force u64) cputime_one_jiffy;
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} else if (irqtime_account_si_update()) {
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cpustat[CPUTIME_SOFTIRQ] += (__force u64) cputime_one_jiffy;
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} else if (this_cpu_ksoftirqd() == p) {
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/*
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* ksoftirqd time do not get accounted in cpu_softirq_time.
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* So, we have to handle it separately here.
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* Also, p->stime needs to be updated for ksoftirqd.
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*/
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__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
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CPUTIME_SOFTIRQ);
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} else if (user_tick) {
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account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
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} else if (p == rq->idle) {
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account_idle_time(cputime_one_jiffy);
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} else if (p->flags & PF_VCPU) { /* System time or guest time */
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account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled);
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} else {
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__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
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CPUTIME_SYSTEM);
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}
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}
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static void irqtime_account_idle_ticks(int ticks)
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{
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int i;
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struct rq *rq = this_rq();
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for (i = 0; i < ticks; i++)
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irqtime_account_process_tick(current, 0, rq);
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}
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#else /* CONFIG_IRQ_TIME_ACCOUNTING */
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static inline void irqtime_account_idle_ticks(int ticks) {}
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static inline void irqtime_account_process_tick(struct task_struct *p, int user_tick,
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struct rq *rq) {}
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#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
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#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
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/*
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* Account a single tick of cpu time.
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* @p: the process that the cpu time gets accounted to
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* @user_tick: indicates if the tick is a user or a system tick
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*/
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void account_process_tick(struct task_struct *p, int user_tick)
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{
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cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
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struct rq *rq = this_rq();
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if (vtime_accounting_enabled())
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return;
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if (sched_clock_irqtime) {
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irqtime_account_process_tick(p, user_tick, rq);
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return;
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}
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if (steal_account_process_tick())
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return;
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if (user_tick)
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account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
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else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
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account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
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one_jiffy_scaled);
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else
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account_idle_time(cputime_one_jiffy);
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}
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/*
|
|
* Account multiple ticks of steal time.
|
|
* @p: the process from which the cpu time has been stolen
|
|
* @ticks: number of stolen ticks
|
|
*/
|
|
void account_steal_ticks(unsigned long ticks)
|
|
{
|
|
account_steal_time(jiffies_to_cputime(ticks));
|
|
}
|
|
|
|
/*
|
|
* Account multiple ticks of idle time.
|
|
* @ticks: number of stolen ticks
|
|
*/
|
|
void account_idle_ticks(unsigned long ticks)
|
|
{
|
|
|
|
if (sched_clock_irqtime) {
|
|
irqtime_account_idle_ticks(ticks);
|
|
return;
|
|
}
|
|
|
|
account_idle_time(jiffies_to_cputime(ticks));
|
|
}
|
|
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
|
|
|
|
/*
|
|
* Use precise platform statistics if available:
|
|
*/
|
|
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
|
|
void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
|
|
{
|
|
*ut = p->utime;
|
|
*st = p->stime;
|
|
}
|
|
|
|
void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
|
|
{
|
|
struct task_cputime cputime;
|
|
|
|
thread_group_cputime(p, &cputime);
|
|
|
|
*ut = cputime.utime;
|
|
*st = cputime.stime;
|
|
}
|
|
|
|
#ifndef __ARCH_HAS_VTIME_TASK_SWITCH
|
|
void vtime_task_switch(struct task_struct *prev)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
if (is_idle_task(prev))
|
|
vtime_account_idle(prev);
|
|
else
|
|
vtime_account_system(prev);
|
|
|
|
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
|
|
vtime_account_user(prev);
|
|
#endif
|
|
arch_vtime_task_switch(prev);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Archs that account the whole time spent in the idle task
|
|
* (outside irq) as idle time can rely on this and just implement
|
|
* vtime_account_system() and vtime_account_idle(). Archs that
|
|
* have other meaning of the idle time (s390 only includes the
|
|
* time spent by the CPU when it's in low power mode) must override
|
|
* vtime_account().
|
|
*/
|
|
#ifndef __ARCH_HAS_VTIME_ACCOUNT
|
|
void vtime_account_irq_enter(struct task_struct *tsk)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
if (!in_interrupt()) {
|
|
/*
|
|
* If we interrupted user, context_tracking_in_user()
|
|
* is 1 because the context tracking don't hook
|
|
* on irq entry/exit. This way we know if
|
|
* we need to flush user time on kernel entry.
|
|
*/
|
|
if (context_tracking_in_user()) {
|
|
vtime_account_user(tsk);
|
|
return;
|
|
}
|
|
|
|
if (is_idle_task(tsk)) {
|
|
vtime_account_idle(tsk);
|
|
return;
|
|
}
|
|
}
|
|
vtime_account_system(tsk);
|
|
}
|
|
EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
|
|
#endif /* __ARCH_HAS_VTIME_ACCOUNT */
|
|
|
|
#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
|
|
|
|
static cputime_t scale_stime(cputime_t stime, cputime_t rtime, cputime_t total)
|
|
{
|
|
u64 temp = (__force u64) rtime;
|
|
|
|
temp *= (__force u64) stime;
|
|
|
|
if (sizeof(cputime_t) == 4)
|
|
temp = div_u64(temp, (__force u32) total);
|
|
else
|
|
temp = div64_u64(temp, (__force u64) total);
|
|
|
|
return (__force cputime_t) temp;
|
|
}
|
|
|
|
/*
|
|
* Adjust tick based cputime random precision against scheduler
|
|
* runtime accounting.
|
|
*/
|
|
static void cputime_adjust(struct task_cputime *curr,
|
|
struct cputime *prev,
|
|
cputime_t *ut, cputime_t *st)
|
|
{
|
|
cputime_t rtime, stime, total;
|
|
|
|
stime = curr->stime;
|
|
total = stime + curr->utime;
|
|
|
|
/*
|
|
* Tick based cputime accounting depend on random scheduling
|
|
* timeslices of a task to be interrupted or not by the timer.
|
|
* Depending on these circumstances, the number of these interrupts
|
|
* may be over or under-optimistic, matching the real user and system
|
|
* cputime with a variable precision.
|
|
*
|
|
* Fix this by scaling these tick based values against the total
|
|
* runtime accounted by the CFS scheduler.
|
|
*/
|
|
rtime = nsecs_to_cputime(curr->sum_exec_runtime);
|
|
|
|
if (total)
|
|
stime = scale_stime(stime, rtime, total);
|
|
else
|
|
stime = rtime;
|
|
|
|
/*
|
|
* If the tick based count grows faster than the scheduler one,
|
|
* the result of the scaling may go backward.
|
|
* Let's enforce monotonicity.
|
|
*/
|
|
prev->stime = max(prev->stime, stime);
|
|
prev->utime = max(prev->utime, rtime - prev->stime);
|
|
|
|
*ut = prev->utime;
|
|
*st = prev->stime;
|
|
}
|
|
|
|
void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
|
|
{
|
|
struct task_cputime cputime = {
|
|
.sum_exec_runtime = p->se.sum_exec_runtime,
|
|
};
|
|
|
|
task_cputime(p, &cputime.utime, &cputime.stime);
|
|
cputime_adjust(&cputime, &p->prev_cputime, ut, st);
|
|
}
|
|
|
|
/*
|
|
* Must be called with siglock held.
|
|
*/
|
|
void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
|
|
{
|
|
struct task_cputime cputime;
|
|
|
|
thread_group_cputime(p, &cputime);
|
|
cputime_adjust(&cputime, &p->signal->prev_cputime, ut, st);
|
|
}
|
|
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
|
|
|
|
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
|
|
static unsigned long long vtime_delta(struct task_struct *tsk)
|
|
{
|
|
unsigned long long clock;
|
|
|
|
clock = sched_clock();
|
|
if (clock < tsk->vtime_snap)
|
|
return 0;
|
|
|
|
return clock - tsk->vtime_snap;
|
|
}
|
|
|
|
static cputime_t get_vtime_delta(struct task_struct *tsk)
|
|
{
|
|
unsigned long long delta = vtime_delta(tsk);
|
|
|
|
WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_SLEEPING);
|
|
tsk->vtime_snap += delta;
|
|
|
|
/* CHECKME: always safe to convert nsecs to cputime? */
|
|
return nsecs_to_cputime(delta);
|
|
}
|
|
|
|
static void __vtime_account_system(struct task_struct *tsk)
|
|
{
|
|
cputime_t delta_cpu = get_vtime_delta(tsk);
|
|
|
|
account_system_time(tsk, irq_count(), delta_cpu, cputime_to_scaled(delta_cpu));
|
|
}
|
|
|
|
void vtime_account_system(struct task_struct *tsk)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
__vtime_account_system(tsk);
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_account_irq_exit(struct task_struct *tsk)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
if (context_tracking_in_user())
|
|
tsk->vtime_snap_whence = VTIME_USER;
|
|
__vtime_account_system(tsk);
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_account_user(struct task_struct *tsk)
|
|
{
|
|
cputime_t delta_cpu;
|
|
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
delta_cpu = get_vtime_delta(tsk);
|
|
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
tsk->vtime_snap_whence = VTIME_SYS;
|
|
account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_user_enter(struct task_struct *tsk)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
tsk->vtime_snap_whence = VTIME_USER;
|
|
__vtime_account_system(tsk);
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_guest_enter(struct task_struct *tsk)
|
|
{
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
__vtime_account_system(tsk);
|
|
current->flags |= PF_VCPU;
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_guest_exit(struct task_struct *tsk)
|
|
{
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
__vtime_account_system(tsk);
|
|
current->flags &= ~PF_VCPU;
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_account_idle(struct task_struct *tsk)
|
|
{
|
|
cputime_t delta_cpu = get_vtime_delta(tsk);
|
|
|
|
account_idle_time(delta_cpu);
|
|
}
|
|
|
|
bool vtime_accounting_enabled(void)
|
|
{
|
|
return context_tracking_active();
|
|
}
|
|
|
|
void arch_vtime_task_switch(struct task_struct *prev)
|
|
{
|
|
write_seqlock(&prev->vtime_seqlock);
|
|
prev->vtime_snap_whence = VTIME_SLEEPING;
|
|
write_sequnlock(&prev->vtime_seqlock);
|
|
|
|
write_seqlock(¤t->vtime_seqlock);
|
|
current->vtime_snap_whence = VTIME_SYS;
|
|
current->vtime_snap = sched_clock();
|
|
write_sequnlock(¤t->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_init_idle(struct task_struct *t)
|
|
{
|
|
unsigned long flags;
|
|
|
|
write_seqlock_irqsave(&t->vtime_seqlock, flags);
|
|
t->vtime_snap_whence = VTIME_SYS;
|
|
t->vtime_snap = sched_clock();
|
|
write_sequnlock_irqrestore(&t->vtime_seqlock, flags);
|
|
}
|
|
|
|
cputime_t task_gtime(struct task_struct *t)
|
|
{
|
|
unsigned long flags;
|
|
unsigned int seq;
|
|
cputime_t gtime;
|
|
|
|
do {
|
|
seq = read_seqbegin_irqsave(&t->vtime_seqlock, flags);
|
|
|
|
gtime = t->gtime;
|
|
if (t->flags & PF_VCPU)
|
|
gtime += vtime_delta(t);
|
|
|
|
} while (read_seqretry_irqrestore(&t->vtime_seqlock, seq, flags));
|
|
|
|
return gtime;
|
|
}
|
|
|
|
/*
|
|
* Fetch cputime raw values from fields of task_struct and
|
|
* add up the pending nohz execution time since the last
|
|
* cputime snapshot.
|
|
*/
|
|
static void
|
|
fetch_task_cputime(struct task_struct *t,
|
|
cputime_t *u_dst, cputime_t *s_dst,
|
|
cputime_t *u_src, cputime_t *s_src,
|
|
cputime_t *udelta, cputime_t *sdelta)
|
|
{
|
|
unsigned long flags;
|
|
unsigned int seq;
|
|
unsigned long long delta;
|
|
|
|
do {
|
|
*udelta = 0;
|
|
*sdelta = 0;
|
|
|
|
seq = read_seqbegin_irqsave(&t->vtime_seqlock, flags);
|
|
|
|
if (u_dst)
|
|
*u_dst = *u_src;
|
|
if (s_dst)
|
|
*s_dst = *s_src;
|
|
|
|
/* Task is sleeping, nothing to add */
|
|
if (t->vtime_snap_whence == VTIME_SLEEPING ||
|
|
is_idle_task(t))
|
|
continue;
|
|
|
|
delta = vtime_delta(t);
|
|
|
|
/*
|
|
* Task runs either in user or kernel space, add pending nohz time to
|
|
* the right place.
|
|
*/
|
|
if (t->vtime_snap_whence == VTIME_USER || t->flags & PF_VCPU) {
|
|
*udelta = delta;
|
|
} else {
|
|
if (t->vtime_snap_whence == VTIME_SYS)
|
|
*sdelta = delta;
|
|
}
|
|
} while (read_seqretry_irqrestore(&t->vtime_seqlock, seq, flags));
|
|
}
|
|
|
|
|
|
void task_cputime(struct task_struct *t, cputime_t *utime, cputime_t *stime)
|
|
{
|
|
cputime_t udelta, sdelta;
|
|
|
|
fetch_task_cputime(t, utime, stime, &t->utime,
|
|
&t->stime, &udelta, &sdelta);
|
|
if (utime)
|
|
*utime += udelta;
|
|
if (stime)
|
|
*stime += sdelta;
|
|
}
|
|
|
|
void task_cputime_scaled(struct task_struct *t,
|
|
cputime_t *utimescaled, cputime_t *stimescaled)
|
|
{
|
|
cputime_t udelta, sdelta;
|
|
|
|
fetch_task_cputime(t, utimescaled, stimescaled,
|
|
&t->utimescaled, &t->stimescaled, &udelta, &sdelta);
|
|
if (utimescaled)
|
|
*utimescaled += cputime_to_scaled(udelta);
|
|
if (stimescaled)
|
|
*stimescaled += cputime_to_scaled(sdelta);
|
|
}
|
|
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
|