[PATCH v4 1/5] sched: rework of sched_domain topology definition

Vincent Guittot vincent.guittot at linaro.org
Fri Apr 18 04:34:30 PDT 2014


On 18 April 2014 12:56, Peter Zijlstra <peterz at infradead.org> wrote:
> On Fri, Apr 11, 2014 at 11:44:37AM +0200, Vincent Guittot wrote:
>> We replace the old way to configure the scheduler topology with a new method
>> which enables a platform to declare additionnal level (if needed).
>>
>> We still have a default topology table definition that can be used by platform
>> that don't want more level than the SMT, MC, CPU and NUMA ones. This table can
>> be overwritten by an arch which either wants to add new level where a load
>> balance make sense like BOOK or powergating level or wants to change the flags
>> configuration of some levels.
>>
>> For each level, we need a function pointer that returns cpumask for each cpu,
>> a function pointer that returns the flags for the level and a name. Only flags
>> that describe topology, can be set by an architecture. The current topology
>> flags are:
>>  SD_SHARE_CPUPOWER
>>  SD_SHARE_PKG_RESOURCES
>>  SD_NUMA
>>  SD_ASYM_PACKING
>>
>> Then, each level must be a subset on the next one. The build sequence of the
>> sched_domain will take care of removing useless levels like those with 1 CPU
>> and those with the same CPU span and no more relevant information for
>> load balancing than its childs.
>>
>> Signed-off-by: Vincent Guittot <vincent.guittot at linaro.org>
>> Reviewed-by: Preeti U Murthy <preeti at linux.vnet.ibm.com>
>
> On x86_64 defconfig this gets me:
>
> kernel/sched/core.c: In function 'sched_init_numa':
> kernel/sched/core.c:6197:4: warning: initialization makes pointer from integer without a cast [enabled by default]
> kernel/sched/core.c:6197:4: warning: (near initialization for '(anonymous).sd_flags') [enabled by default]

Sorry, while moving from int to function pointer, i forgot to change
the numa part

I'm going to send a fix right now


>



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