• Peter Zijlstra's avatar
    sched: Allow for overlapping sched_domain spans · e3589f6c
    Peter Zijlstra authored
    Allow for sched_domain spans that overlap by giving such domains their
    own sched_group list instead of sharing the sched_groups amongst
    each-other.
    
    This is needed for machines with more than 16 nodes, because
    sched_domain_node_span() will generate a node mask from the
    16 nearest nodes without regard if these masks have any overlap.
    
    Currently sched_domains have a sched_group that maps to their child
    sched_domain span, and since there is no overlap we share the
    sched_group between the sched_domains of the various CPUs. If however
    there is overlap, we would need to link the sched_group list in
    different ways for each cpu, and hence sharing isn't possible.
    
    In order to solve this, allocate private sched_groups for each CPU's
    sched_domain but have the sched_groups share a sched_group_power
    structure such that we can uniquely track the power.
    Reported-and-tested-by: default avatarAnton Blanchard <anton@samba.org>
    Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@elte.hu>
    e3589f6c
sched.c 221 KB