On 05.12.20 00:53, Andrew Cooper wrote:
> On 01/12/2020 08:21, Juergen Gross wrote:
>> Support scheduling granularity per cpupool. Setting the granularity is
>> done via hypfs, which needed to gain dynamical entries for that
>> purpose.
>>
>> Apart from the hypfs related additional functionality the main change
>> for cpupools was the support for moving a domain to a new granularity,
>> as this requires to modify the scheduling unit/vcpu relationship.
>>
>> I have tried to do the hypfs modifications in a rather generic way in
>> order to be able to use the same infrastructure in other cases, too
>> (e.g. for per-domain entries).
>>
>> The complete series has been tested by creating cpupools with different
>> granularities and moving busy and idle domains between those.
>>
>> Changes in V2:
>> - Added several new patches, especially for some further cleanups in
>>    cpupool.c.
>> - Completely reworked the locking scheme with dynamical directories:
>>    locking of resources (cpupools in this series) is now done via new
>>    callbacks which are called when traversing the hypfs tree. This
>>    removes the need to add locking to each hypfs related cpupool
>>    function and it ensures data integrity across multiple callbacks.
>> - Reordered the first few patches in order to have already acked
>>    patches in pure cleanup patches first.
>> - Addressed several comments.
>>
>> Juergen Gross (17):
>>    xen/cpupool: add cpu to sched_res_mask when removing it from cpupool
>>    xen/cpupool: add missing bits for per-cpupool scheduling granularity
>>    xen/cpupool: sort included headers in cpupool.c
>>    xen/cpupool: switch cpupool id to unsigned
>>    xen/cpupool: switch cpupool list to normal list interface
>>    xen/cpupool: use ERR_PTR() for returning error cause from
>>      cpupool_create()
>>    xen/cpupool: support moving domain between cpupools with different
>>      granularity
>>    docs: fix hypfs path documentation
>>    xen/hypfs: move per-node function pointers into a dedicated struct
>>    xen/hypfs: pass real failure reason up from hypfs_get_entry()
>>    xen/hypfs: add getsize() and findentry() callbacks to hypfs_funcs
>>    xen/hypfs: add new enter() and exit() per node callbacks
>>    xen/hypfs: support dynamic hypfs nodes
>>    xen/hypfs: add support for id-based dynamic directories
>>    xen/cpupool: add cpupool directories
>>    xen/cpupool: add scheduling granularity entry to cpupool entries
>>    xen/cpupool: make per-cpupool sched-gran hypfs node writable
> 
> Gitlab CI is fairly (but not completely) reliably hitting an failure in
> ARM randconfig against this series only.
> 
> https://gitlab.com/xen-project/patchew/xen/-/pipelines/225445864 is one
> example.
> 
> Error is:
> 
> cpupool.c:102:12: error: 'sched_gran_get' defined but not used
> [-Werror=unused-function]
>    102 | static int sched_gran_get(const char *str, enum sched_gran *mode)
>        |            ^~~~~~~~~~~~~~
> 

Ah, this is without CONFIG_HYPFS.

Will fix.


Juergen