• Zhen Lei's avatar
    mm: only display online cpus of the numa node · 064f0e93
    Zhen Lei authored
    When I execute numactl -H (which reads /sys/devices/system/node/nodeX/cpumap
    and displays cpumask_of_node for each node), I get different result
    on X86 and arm64.  For each numa node, the former only displayed online
    CPUs, and the latter displayed all possible CPUs.  Unfortunately, both
    Linux documentation and numactl manual have not described it clear.
    
    I sent a mail to ask for help, and Michal Hocko replied that he
    preferred to print online cpus because it doesn't really make much sense
    to bind anything on offline nodes.
    
    Will said:
     "I suspect the vast majority (if not all) code that reads this file was
      developed for x86, so having the same behaviour for arm64 sounds like
      something we should do ASAP before people try to special case with
      things like #ifdef __aarch64__. I'd rather have this in 4.14 if
      possible."
    
    Link: http://lkml.kernel.org/r/1506678805-15392-2-git-send-email-thunder.leizhen@huawei.comSigned-off-by: default avatarZhen Lei <thunder.leizhen@huawei.com>
    Acked-by: default avatarMichal Hocko <mhocko@suse.com>
    Cc: Catalin Marinas <catalin.marinas@arm.com>
    Cc: Will Deacon <will.deacon@arm.com>
    Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Cc: Tianhong Ding <dingtianhong@huawei.com>
    Cc: Hanjun Guo <guohanjun@huawei.com>
    Cc: Libin <huawei.libin@huawei.com>
    Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    064f0e93
node.c 18.7 KB