Re: [PATCH 3/5] tick/broadcast: Prefer per-cpu oneshot wakeup timers to broadcast
From: Will Deacon <will@kernel.org>
Date: 2021-05-21 12:18:52
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On Fri, May 21, 2021 at 12:25:03PM +0100, Will Deacon wrote:
On Fri, May 21, 2021 at 05:25:41AM +0300, Mika Penttilä wrote:quoted
On 20.5.2021 21.47, Will Deacon wrote:quoted
/* * Conditionally install/replace broadcast device */ -void tick_install_broadcast_device(struct clock_event_device *dev) +void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { struct clock_event_device *cur = tick_broadcast_device.evtdev; + if (tick_set_oneshot_wakeup_device(dev, cpu)) + return; + if (!tick_check_broadcast_device(cur, dev)) return;Does this disable hpet registering as a global broadcast device on x86 ? I think it starts with cpumask = cpu0 so it qualifies for a percpu wakeup timer.Well spotted, I think you're probably right. I'll try to reproduce on my laptop to confirm, but I hadn't noticed the tricks played with the cpumask on x86. I'll probably need to rework things so that we install the broadcast timer first, but prefer global devices.
... and in doing that, I noticed my module refcounting is off as well so I'll definitely be spinning a v2. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel