From: Heiko Carstens Date: Wed, 18 Feb 2026 14:20:10 +0000 (+0100) Subject: s390/vtime: Use __this_cpu_read() / get rid of READ_ONCE() X-Git-Tag: ceph-for-7.0-rc4~77^2~2^2~2 X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=e282ccd308de7b2a65eb4596da8030c18b543071;p=ceph-client.git s390/vtime: Use __this_cpu_read() / get rid of READ_ONCE() do_account_vtime() runs always with interrupts disabled, therefore use __this_cpu_read() instead of this_cpu_read() to get rid of a pointless preempt_disable() / preempt_enable() pair. Also there are no concurrent writers to the cpu time accounting fields in lowcore. Therefore get rid of READ_ONCE() usages. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik --- diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index 122d30b10440..4111ff4d727c 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -137,23 +137,16 @@ static int do_account_vtime(struct task_struct *tsk) lc->system_timer += timer; /* Update MT utilization calculation */ - if (smp_cpu_mtid && - time_after64(jiffies_64, this_cpu_read(mt_scaling_jiffies))) + if (smp_cpu_mtid && time_after64(jiffies_64, __this_cpu_read(mt_scaling_jiffies))) update_mt_scaling(); /* Calculate cputime delta */ - user = update_tsk_timer(&tsk->thread.user_timer, - READ_ONCE(lc->user_timer)); - guest = update_tsk_timer(&tsk->thread.guest_timer, - READ_ONCE(lc->guest_timer)); - system = update_tsk_timer(&tsk->thread.system_timer, - READ_ONCE(lc->system_timer)); - hardirq = update_tsk_timer(&tsk->thread.hardirq_timer, - READ_ONCE(lc->hardirq_timer)); - softirq = update_tsk_timer(&tsk->thread.softirq_timer, - READ_ONCE(lc->softirq_timer)); - lc->steal_timer += - clock - user - guest - system - hardirq - softirq; + user = update_tsk_timer(&tsk->thread.user_timer, lc->user_timer); + guest = update_tsk_timer(&tsk->thread.guest_timer, lc->guest_timer); + system = update_tsk_timer(&tsk->thread.system_timer, lc->system_timer); + hardirq = update_tsk_timer(&tsk->thread.hardirq_timer, lc->hardirq_timer); + softirq = update_tsk_timer(&tsk->thread.softirq_timer, lc->softirq_timer); + lc->steal_timer += clock - user - guest - system - hardirq - softirq; /* Push account value */ if (user) {