Messages in this thread Patch in this message | | | Subject | Re: [PATCH v6 01/24] x86/resctrl: Split struct rdt_resource | From | James Morse <> | Date | Wed, 28 Jul 2021 17:17:03 +0100 |
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Hello,
On 15/07/2021 18:30, James Morse wrote: > resctrl is the defacto Linux ABI for SoC resource partitioning features. > > To support it on another architecture, it needs to be abstracted from > the features provided by Intel RDT and AMD PQoS, and moved to /fs/. > struct rdt_resource contains a mix of architecture private details > and properties of the filesystem interface user-space uses. > > Start by splitting struct rdt_resource, into an architecture private > 'hw' struct, which contains the common resctrl structure that would be > used by any architecture.
> The foreach helpers are most commonly used by > the filesystem code, and should return the common resctrl structure. > for_each_rdt_resource() is changed to walk the common structure in its > parent arch private structure.
[...]
> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h > index 6a5f60a37219..88d71c889328 100644 > --- a/arch/x86/kernel/cpu/resctrl/internal.h > +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> @@ -524,33 +439,42 @@ enum { > RDT_NUM_RESOURCES, > }; > > +static inline struct rdt_resource *resctrl_inc(struct rdt_resource *res) > +{ > + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(res); > + > + hw_res++; > + return &hw_res->r_resctrl; > +} > + > +/* > + * To return the common struct rdt_resource, which is contained in struct > + * rdt_hw_resource, walk the resctrl member of struct rdt_hw_resource. > + * This makes the limit the resctrl member past the end of the array. > + */ > #define for_each_rdt_resource(r) \ > - for (r = rdt_resources_all; r < rdt_resources_all + RDT_NUM_RESOURCES;\ > - r++) > + for (r = &rdt_resources_all[0].r_resctrl; \ > + r < &rdt_resources_all[RDT_NUM_RESOURCES].r_resctrl; \ > + r = resctrl_inc(r))
Kbuild robot reports UBSAN doesn't like this, presumably the dastardly compiler has gone and generated some accesses. Easily fixed, (but now looks less like the original)
v6's branch gets a patch on top, I'll squash this into v7: ----%<---- @@ -441,11 +441,10 @@ int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable); /* * To return the common struct rdt_resource, which is contained in struct * rdt_hw_resource, walk the resctrl member of struct rdt_hw_resource. - * This makes the limit the resctrl member past the end of the array. */ #define for_each_rdt_resource(r) \ for (r = &rdt_resources_all[0].r_resctrl; \ - r < &rdt_resources_all[RDT_NUM_RESOURCES].r_resctrl; \ + r <= &rdt_resources_all[RDT_NUM_RESOURCES - 1].r_resctrl; \ r = resctrl_inc(r))
#define for_each_capable_rdt_resource(r) \ ----%<----
Thanks,
James
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