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    SubjectRe: [PATCH v1 30/31] x86/resctrl: Move the filesystem bits to headers visible to fs/resctrl
    On Mon, Apr 15, 2024 at 11:03:32AM -0700, Reinette Chatre wrote:
    > Hi Dave,
    >
    > On 4/12/2024 9:20 AM, Dave Martin wrote:
    > > On Thu, Apr 11, 2024 at 10:43:55AM -0700, Reinette Chatre wrote:
    > >> Hi Dave,
    > >>
    > >> On 4/11/2024 7:28 AM, Dave Martin wrote:
    > >>> On Mon, Apr 08, 2024 at 08:42:00PM -0700, Reinette Chatre wrote:
    > >>>> Hi James,
    > >>>>
    > >>>> On 3/21/2024 9:51 AM, James Morse wrote:
    > >>>> ..
    > >>>>> diff --git a/include/linux/resctrl_types.h b/include/linux/resctrl_types.h
    > >>>>> index 4788bd95dac6..fe0b10b589c0 100644
    > >>>>> --- a/include/linux/resctrl_types.h
    > >>>>> +++ b/include/linux/resctrl_types.h
    > >>>>> @@ -7,6 +7,36 @@
    > >>>>> #ifndef __LINUX_RESCTRL_TYPES_H
    > >>>>> #define __LINUX_RESCTRL_TYPES_H
    > >>>>>
    > >>>>> +#define CQM_LIMBOCHECK_INTERVAL 1000
    > >>>>> +
    > >>>>> +#define MBM_CNTR_WIDTH_BASE 24
    > >>>>> +#define MBM_OVERFLOW_INTERVAL 1000
    > >>>>> +#define MAX_MBA_BW 100u
    > >>>>> +#define MBA_IS_LINEAR 0x4
    > >>>>> +
    > >>>>> +/* rdtgroup.flags */
    > >>>>> +#define RDT_DELETED 1
    > >>>>> +
    > >>>>> +/* rftype.flags */
    > >>>>> +#define RFTYPE_FLAGS_CPUS_LIST 1
    > >>>>> +
    > >>>>> +/*
    > >>>>> + * Define the file type flags for base and info directories.
    > >>>>> + */
    > >>>>> +#define RFTYPE_INFO BIT(0)
    > >>>>> +#define RFTYPE_BASE BIT(1)
    > >>>>> +#define RFTYPE_CTRL BIT(4)
    > >>>>> +#define RFTYPE_MON BIT(5)
    > >>>>> +#define RFTYPE_TOP BIT(6)
    > >>>>> +#define RFTYPE_RES_CACHE BIT(8)
    > >>>>> +#define RFTYPE_RES_MB BIT(9)
    > >>>>> +#define RFTYPE_DEBUG BIT(10)
    > >>>>> +#define RFTYPE_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL)
    > >>>>> +#define RFTYPE_MON_INFO (RFTYPE_INFO | RFTYPE_MON)
    > >>>>> +#define RFTYPE_TOP_INFO (RFTYPE_INFO | RFTYPE_TOP)
    > >>>>> +#define RFTYPE_CTRL_BASE (RFTYPE_BASE | RFTYPE_CTRL)
    > >>>>> +#define RFTYPE_MON_BASE (RFTYPE_BASE | RFTYPE_MON)
    > >>>>> +
    > >>>>> /* Reads to Local DRAM Memory */
    > >>>>> #define READS_TO_LOCAL_MEM BIT(0)
    > >>>>>
    > >>>>
    > >>>> Not all these new seem to belong in this file. Could you please confirm?
    > >>>>
    > >>>> For example:
    > >>>> Earlier in series it was mentioned that struct rdtgroup is private to the
    > >>>> fs so having RDT_DELETED is unexpected as it implies access to struct rdtgroup.
    > >>>>
    > >>>> CQM_LIMBOCHECK_INTERVAL seems private to the fs code, so too
    > >>>> RFTYPE_FLAGS_CPUS_LIST.
    > >>>>
    > >>>> Reinette
    > >>>>
    > >>>
    > >>> I'll flag this for James to review.
    > >>>
    > >>> These have to be moved out of the x86 private headers, but you're right
    > >>> that some of them seem logically private to the resctrl core.
    > >>>
    > >>> I guess some of these could move to fs/resctrl/internal.h?
    > >>
    > >> It looks to me that way.
    > >>
    > >>>
    > >>> OTOH, might it be preferable to keep all the flag definitions for a
    > >>> given member together for ease of maintenance, even if some are for
    > >>> resctrl internal use only?
    > >>
    > >> Indeed, those RFTYPE flags really seem to be fs code but I agree that
    > >> architectures' use of RFTYPE_RES_CACHE and RFTYPE_RES_MB does make this
    > >> complicated and having these in a central place is reasonable to me.
    > >>
    > >> Reinette
    > >
    > > Maybe we could split these into two groups, and clearly comment the ones
    > > that have no user outside resctrl as internal use only?
    >
    > Another option to consider, which I think you hinted about earlier, is
    > to add an enum that maps to the RFTYPE_RES_CACHE and RFTYPE_RES_MB
    > flags. Just like, for example, RDTCTRL_GROUP maps to RFTYPE_CTRL.
    > The new enum can then be used similar to enum rdt_group_type to pick the
    > appropriate files based on RFTYPE_RES_CACHE or RFTYPE_RES_MB.
    >
    > >
    > > That's not as clean as removing those definitions from a shared header,
    > > but at least would help document the issue until/unless a better
    > > solution is found...
    > >
    > > Cheers
    > > ---Dave

    (Note, I seem to have responded to that suggestion via my reply on patch 3,
    rather than here:

    "x86/resctrl: Move ctrlval string parsing policy away from the arch code"
    https://lore.kernel.org/lkml/Zh6kRMkqVpu0Km4l@e133380.arm.com/ )

    Cheers
    ---Dave

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