diff options
Diffstat (limited to 'features/rt/irqtime-Make-accounting-correct-on-RT.patch')
| -rw-r--r-- | features/rt/irqtime-Make-accounting-correct-on-RT.patch | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/features/rt/irqtime-Make-accounting-correct-on-RT.patch b/features/rt/irqtime-Make-accounting-correct-on-RT.patch new file mode 100644 index 00000000..bb84cb23 --- /dev/null +++ b/features/rt/irqtime-Make-accounting-correct-on-RT.patch @@ -0,0 +1,53 @@ +From 02a22f4cb3638326b34be9b98415ab6f2718f071 Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner <tglx@linutronix.de> +Date: Tue, 9 Mar 2021 09:55:54 +0100 +Subject: [PATCH 056/191] irqtime: Make accounting correct on RT + +vtime_account_irq and irqtime_account_irq() base checks on preempt_count() +which fails on RT because preempt_count() does not contain the softirq +accounting which is seperate on RT. + +These checks do not need the full preempt count as they only operate on the +hard and softirq sections. + +Use irq_count() instead which provides the correct value on both RT and non +RT kernels. The compiler is clever enough to fold the masking for !RT: + + 99b: 65 8b 05 00 00 00 00 mov %gs:0x0(%rip),%eax + - 9a2: 25 ff ff ff 7f and $0x7fffffff,%eax + + 9a2: 25 00 ff ff 00 and $0xffff00,%eax + +Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Reviewed-by: Frederic Weisbecker <frederic@kernel.org> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + kernel/sched/cputime.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c +index 5f611658eeab..2c36a5fad589 100644 +--- a/kernel/sched/cputime.c ++++ b/kernel/sched/cputime.c +@@ -60,7 +60,7 @@ void irqtime_account_irq(struct task_struct *curr, unsigned int offset) + cpu = smp_processor_id(); + delta = sched_clock_cpu(cpu) - irqtime->irq_start_time; + irqtime->irq_start_time += delta; +- pc = preempt_count() - offset; ++ pc = irq_count() - offset; + + /* + * We do not account for softirq time from ksoftirqd here. +@@ -421,7 +421,7 @@ void vtime_task_switch(struct task_struct *prev) + + void vtime_account_irq(struct task_struct *tsk, unsigned int offset) + { +- unsigned int pc = preempt_count() - offset; ++ unsigned int pc = irq_count() - offset; + + if (pc & HARDIRQ_OFFSET) { + vtime_account_hardirq(tsk); +-- +2.19.1 + |