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s390/vtime: Fix virtual timer forwarding

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Since delayed accounting of system time [1] the virtual timer is
forwarded by do_account_vtime() but also vtime_account_kernel(),
vtime_account_softirq(), and vtime_account_hardirq(). This leads
to double accounting of system, guest, softirq, and hardirq time.

Remove accounting from the vtime_account*() family to restore old behavior.

There is only one user of the vtimer interface, which might explain
why nobody noticed this so far.

Fixes: b7394a5f4c ("sched/cputime, s390: Implement delayed accounting of system time") [1]
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Heiko Carstens
2026-02-18 15:20:05 +01:00
committed by Vasily Gorbik
parent 0d785e2c32
commit dbc0fb3567
1 changed files with 2 additions and 16 deletions
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18
arch/s390/kernel/vtime.c
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@@ -225,10 +225,6 @@ static u64 vtime_delta(void)
return timer - lc->last_update_timer;
}
/*
* Update process times based on virtual cpu times stored by entry.S
* to the lowcore fields user_timer, system_timer & steal_clock.
*/
void vtime_account_kernel(struct task_struct *tsk)
{
struct lowcore *lc = get_lowcore();
@@ -238,27 +234,17 @@ void vtime_account_kernel(struct task_struct *tsk)
lc->guest_timer += delta;
else
lc->system_timer += delta;
virt_timer_forward(delta);
}
EXPORT_SYMBOL_GPL(vtime_account_kernel);
void vtime_account_softirq(struct task_struct *tsk)
{
u64 delta = vtime_delta();
get_lowcore()->softirq_timer += delta;
virt_timer_forward(delta);
get_lowcore()->softirq_timer += vtime_delta();
}
void vtime_account_hardirq(struct task_struct *tsk)
{
u64 delta = vtime_delta();
get_lowcore()->hardirq_timer += delta;
virt_timer_forward(delta);
get_lowcore()->hardirq_timer += vtime_delta();
}
/*