• Peter Zijlstra's avatar
    perf, x86: Fix AMD hotplug & constraint initialization · b38b24ea
    Peter Zijlstra authored
    Commit 3f6da390 ("perf: Rework and fix the arch CPU-hotplug hooks") moved
    the amd northbridge allocation from CPUS_ONLINE to CPUS_PREPARE_UP
    however amd_nb_id() doesn't work yet on prepare so it would simply bail
    basically reverting to a state where we do not properly track node wide
    constraints - causing weird perf results.
    
    Fix up the AMD NorthBridge initialization code by allocating from
    CPU_UP_PREPARE and installing it from CPU_STARTING once we have the
    proper nb_id. It also properly deals with the allocation failing.
    Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
    [ robustify using amd_has_nb() ]
    Signed-off-by: default avatarStephane Eranian <eranian@google.com>
    LKML-Reference: <1269353485.5109.48.camel@twins>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    b38b24ea
perf_event_amd.c 10 KB