Messages in this thread | | | Date | Thu, 7 Sep 2017 07:59:39 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 4/4][RFC v2] x86/apic: Spread the vectors by choosing the idlest CPU |
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On Wed, 6 Sep 2017, Dan Williams wrote:
> On Tue, Sep 5, 2017 at 11:15 PM, Christoph Hellwig <hch@lst.de> wrote: > > On Wed, Sep 06, 2017 at 12:13:38PM +0800, Yu Chen wrote: > >> I agree, the driver could be rewritten, but it might take some time, so > >> meanwhile I'm looking at also other possible optimization. > > > > Which driver are we talking about anyway? Let's start looking at it > > and fix the issue there. > > As far as I understand, it's already fixed there: > > commit 7c9ae7f053e9e896c24fd23595ba369a5fe322e1
-ENOSUCHCOMMIT
> Author: Carolyn Wyborny <carolyn.wyborny@intel.com> > Date: Tue Jun 20 15:16:53 2017 -0700 > > i40e: Fix for trace found with S4 state > > This patch fixes a problem found in systems when entering > S4 state. This patch fixes the problem by ensuring that > the misc vector's IRQ is disabled as well. Without this > patch a stack trace can be seen upon entering S4 state. > > However this seems like something that should be handled generically > in the irq-core especially since commit c5cb83bb337c > "genirq/cpuhotplug: Handle managed IRQs on CPU hotplug" was headed in > that direction. It's otherwise non-obvious when a driver needs to > release and re-acquire interrupts or be reworked to use managed > interrupts.
There are two problems here:
1) The driver allocates 300 interrupts and uses exactly 8 randomly chosen ones.
2) It's not using the managed affinity mechanics, so the interrupts cannot be sanely handled by the kernel, neither affinity wise nor at hotplug time.
Thanks,
tglx
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