Messages in this thread | | | Date | Wed, 27 May 2015 14:52:36 +0530 | From | Viresh Kumar <> | Subject | Re: [patch 4/7] timer: Replace timer base by a cpu index |
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On 26-05-15, 22:50, Thomas Gleixner wrote: > static struct tvec_base *lock_timer_base(struct timer_list *timer, > unsigned long *flags) > __acquires(timer->base->lock) > { > - struct tvec_base *base; > - > for (;;) { > - struct tvec_base *prelock_base = timer->base; > - base = tbase_get_base(prelock_base); > - if (likely(base != NULL)) { > + u32 tf = timer->flags; > + struct tvec_base *base; > + > + if (!(tf & TIMER_MIGRATING)) { > + base = per_cpu_ptr(&tvec_bases, tf & TIMER_CPUMASK); > spin_lock_irqsave(&base->lock, *flags); > - if (likely(prelock_base == timer->base)) > + if (timer->flags == tf) > return base; > - /* The timer has migrated to another CPU */
Maybe we should retain this comment. Its helpful for people who aren't very familiar with timer core.
> static void migrate_timer_list(struct tvec_base *new_base, struct hlist_head *head) > { > struct timer_list *timer; > + int cpu = new_base->cpu; > > while (!hlist_empty(head)) { > timer = hlist_entry(head->first, struct timer_list, entry); > /* We ignore the accounting on the dying cpu */ > detach_timer(timer, false); > - timer_set_base(timer, new_base); > + timer->flags = (timer->flags & ~TIMER_BASEMASK) | cpu;
Because 'cpu' is used only once in this routine, maybe we can use 'new_base->cpu' here and the line will still be exactly 80 columns long.
Not sure, but maybe we can create a inline helper for this operation as it is repeated at multiple places.
Look good otherwise:
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
-- viresh
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