From: tglx@linutronix.de (Thomas Gleixner)
To: linux-snps-arc@lists.infradead.org
Subject: [PATCH v3 03/11] ARC: Allow irq threading
Date: Fri, 25 Aug 2017 23:02:18 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.20.1708252300540.2124@nanos> (raw)
In-Reply-To: <alpine.DEB.2.20.1708252252430.2124@nanos>
On Fri, 25 Aug 2017, Thomas Gleixner wrote:
> On Fri, 25 Aug 2017, Vineet Gupta wrote:
> > On 06/15/2017 01:43 AM, Noam Camus wrote:
> > > From: Noam Camus <noamc at ezchip.com>
> > >
> > > Working with NPS400 we noticed that there is a possibility of L1
> > > interrupt nesting that may run out kernel stack.
> > > The scenario include serving invoke_softirqs() from irq_exit()
> > > and once local_irq_enable() called can hit another one before we
> > > managed to restore last one and pop some place from kernel stack.
> > >
> > > Serving softirqs at dedicated kernel thread may mitigate this.
> > > We see that many architectures, including x86, behave like this.
>
> Well, no. x86 supports that, but that does not mean many user add it to the
> command line.
The real fix for that is to use dedicated irq and softirq stacks instead of
using the potentially deep thread stack for everything. That's what x86 and
others do unconditinally.
Thanks,
tglx
next prev parent reply other threads:[~2017-08-25 21:02 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-15 8:43 [PATCH v3 00/11] plat-eznps upstream cont. set 2 Noam Camus
2017-06-15 8:43 ` [PATCH v3 01/11] ARC: set level of log per CPU during boot to be info level Noam Camus
2017-06-15 8:43 ` [PATCH v3 02/11] ARC: send ipi to all cpus sharing task mm in case of page fault Noam Camus
2017-06-15 8:43 ` [PATCH v3 03/11] ARC: Allow irq threading Noam Camus
2017-08-25 20:45 ` Vineet Gupta
2017-08-25 20:59 ` Thomas Gleixner
2017-08-25 21:02 ` Thomas Gleixner [this message]
2017-06-15 8:43 ` [PATCH v3 04/11] ARC: Add CPU topology Noam Camus
2017-06-15 8:43 ` [PATCH v3 05/11] ARC: Support more than one PGDIR for KVADDR Noam Camus
2017-06-15 8:43 ` [PATCH v3 06/11] ARC: [NUMA] added CONFIG_NUMA for plat-eznps Noam Camus
2017-06-15 8:43 ` [PATCH v3 07/11] ARC: [plat-eznps] new command line argument for HW scheduler at MTM Noam Camus
2017-08-21 17:04 ` Vineet Gupta
2017-08-22 6:16 ` Noam Camus
2017-06-15 8:43 ` [PATCH v3 08/11] ARC: [plat-eznps] Update the init sequence of aux regs per cpu Noam Camus
2017-06-15 8:43 ` [PATCH v3 09/11] ARC: [plat-eznps] Save/Restore extra auxiliary registers Noam Camus
2017-06-15 8:44 ` [PATCH v3 10/11] ARC: [plat-eznps] handle dedicated AUX registers Noam Camus
2017-06-15 8:44 ` [PATCH v3 11/11] ARC: [plat-eznps] avoid toggling of DPC register Noam Camus
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