Re: [PATCH v1 30/31] x86/resctrl: Move the filesystem bits to headers visible to fs/resctrl

[Reinette Chatre]

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