On Fri, Aug 24, 2018 at 11:44:59AM +0100, James Morse wrote: > Hi folks, > > ARM have some upcoming CPU features that are similar to Intel RDT. Resctrl > is the defacto ABI for this sort of thing, but it lives under arch/x86. > > To get existing software working, we need to make resctrl work with arm64. > This series is the first chunk of that. The aim is to move the filesystem/ABI > parts into /fs/resctrl, and implement a second arch backend. > > > What are the ARM features? > Future ARM SoCs may have a feature called MPAM: Memory Partitioning and > Monitoring. This is an umbrella term like RDT, and covers a range of controls > (like CAT) and monitors (like MBM, CMT).
Please send a link to MPAM spec. > > This series is almost all about CDP. MPAM has equivalent functionality, but > it doesn't need enabling, and doesn't affect the available closids. (I'll > try and use Intel terms). MPAM expects the equivalent to IA32_PRQ_MSR to > be configured with an Instruction closid and a Data closid. These are the > same for no-CDP, and different otherwise. There is no need for them to be > adjacent. > > To avoid emulating CDP in arm64's arch code, this series moves all the ABI > parts of the CDP behaviour, (half the closid-space, each having two > configurations) into the filesystem parts of resctrl. These will eventually > be moved to /fs/. Do you have the patches that moves code to /fs/resctrl? > > MPAMs control and monitor configuration is all memory mapped, the base > addresses are discovered via firmware tables, so we won't have a table of > possible resources that just need alloc_enabling. > > Is this it? No... there are another two series of a similar size that > abstract the MBM/CMT overflow threads and avoid 'fs' code accessing things > that have moved into the 'hw' arch specific struct. > > > I'm after feedback on the general approach taken here, bugs, as there are > certainly subtleties I've missed, and any strong-opinions on what should be > arch-specific, and what shouldn't. > > This series is based on v4.18, and can be retrieved from: > git://linux-arm.org/linux-jm.git -b mpam/resctrl_rework/rfc_1 Could you please publish MPAM patches as well? Then we can have better idea on ARM's specific code. This patch set only has Intel RDT part. Thanks. -Fenghua
