Messages in this thread | | | Date | Wed, 20 May 2015 17:48:59 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH 4/4] arm64: gicv3: its: Increase FORCE_MAX_ZONEORDER for Cavium ThunderX |
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On Wed, May 20, 2015 at 02:31:59PM +0200, Robert Richter wrote: > On 20.05.15 13:22:13, Marc Zyngier wrote: > > On Tue, 12 May 2015 18:24:16 +0100 > > Will Deacon <will.deacon@arm.com> wrote: > > > On Tue, May 12, 2015 at 05:20:49PM +0100, Robert Richter wrote: > > > > On 12.05.15 13:30:57, Will Deacon wrote: > > > > > For allocation of 16MB cont. phys mem of a defconfig kernel (4KB > > > > default pagesize) I see this different approaches: > > > > > > 16MB sounds like an awful lot. Is this because you have tonnes of MSIs or > > > a sparse DeviceID space or both? > > > > That's probably due to the sparseness of the DeviceID space. With some > > form of bridge number encoded on top of the BFD number, the device > > table is enormous, and I don't see a nice way to avoid it... > > Right. At the momement out of 21 bits (16MB) we currently have 2 spare > bits, which reduces the actually size used to 4MB. Though, for the > current cpu model we can reduce it at least to 8MB total. > > I will come up with an additional patch setting this to 8MB. > > As said before, I also write on a patch to use CMA.
Can we not reserve a chunk of memory and pass the information to the kernel via DT (/memreserve/ and a new GIC-specific binding)?
-- Catalin
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