From: David Gibson <david@gibson.dropbear.id.au>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Cédric Le Goater" <clg@kaod.org>,
linuxppc-dev@lists.ozlabs.org,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Paul Mackerras" <paulus@samba.org>
Subject: Re: [PATCH 02/10] powerpc/xive: guest exploitation of the XIVE interrupt controller
Date: Thu, 10 Aug 2017 15:54:26 +1000 [thread overview]
Message-ID: <20170810055426.GV13670@umbus.fritz.box> (raw)
In-Reply-To: <1502340360.2563.53.camel@kernel.crashing.org>
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On Thu, Aug 10, 2017 at 02:46:00PM +1000, Benjamin Herrenschmidt wrote:
> On Thu, 2017-08-10 at 14:28 +1000, David Gibson wrote:
> >
> > Also, will POWER9 always have doorbells? In which case you could
> > reduce it to 3 options.
>
> The problem with doorbells on POWER9 guests is that they may have
> to trap and be emulated by the hypervisor, since the guest threads
> on P9 don't have to match the HW threads of the core.
>
> Thus it's quite possible that using XIVE for IPIs is actually faster
> than doorbells in that case.
Ok, well unless there's a compelling reason to use doorbells you can
instead make it 3 cases with POWER9 never using doorbells.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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next prev parent reply other threads:[~2017-08-10 6:10 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-08 8:56 [PATCH 00/10] guest exploitation of the XIVE interrupt controller Cédric Le Goater
2017-08-08 8:56 ` [PATCH 01/10] powerpc/xive: fix OV5_XIVE_EXPLOIT bits Cédric Le Goater
2017-08-08 8:56 ` [PATCH 02/10] powerpc/xive: guest exploitation of the XIVE interrupt controller Cédric Le Goater
2017-08-09 3:53 ` David Gibson
2017-08-09 8:48 ` Cédric Le Goater
2017-08-10 4:28 ` David Gibson
2017-08-10 4:46 ` Benjamin Herrenschmidt
2017-08-10 5:54 ` David Gibson [this message]
2017-08-10 7:04 ` Cédric Le Goater
2017-08-10 6:45 ` Cédric Le Goater
2017-08-10 11:33 ` Benjamin Herrenschmidt
2017-08-10 7:19 ` Cédric Le Goater
2017-08-10 11:36 ` Benjamin Herrenschmidt
2017-08-11 3:55 ` David Gibson
2017-08-08 8:56 ` [PATCH 03/10] powerpc/xive: rename xive_poke_esb in xive_esb_read Cédric Le Goater
2017-08-09 3:55 ` David Gibson
2017-08-09 7:12 ` Cédric Le Goater
2017-08-09 7:31 ` David Gibson
2017-08-08 8:56 ` [PATCH 04/10] powerpc/xive: introduce xive_esb_write Cédric Le Goater
2017-08-08 8:56 ` [PATCH 05/10] powerpc/xive: add the HW IRQ number under xive_irq_data Cédric Le Goater
2017-08-08 8:56 ` [PATCH 06/10] powerpc/xive: introduce H_INT_ESB hcall Cédric Le Goater
2017-08-08 8:56 ` [PATCH 07/10] powerpc/xive: add XIVE exploitation mode to CAS Cédric Le Goater
2017-08-10 10:20 ` Cédric Le Goater
2017-08-08 8:56 ` [PATCH 08/10] powerpc/xive: take into account '/ibm, plat-res-int-priorities' Cédric Le Goater
2017-08-09 4:02 ` [PATCH 08/10] powerpc/xive: take into account '/ibm,plat-res-int-priorities' David Gibson
2017-08-09 7:14 ` Cédric Le Goater
2017-08-10 0:54 ` David Gibson
2017-08-08 8:56 ` [PATCH 09/10] powerpc/xive: improve debugging macros Cédric Le Goater
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