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    SubjectRe: [PATCH 0/8] v5 De-couple sysfs memory directories from memory sections

    Hi Nathan,

    > This set of patches de-couples the idea that there is a single
    > directory in sysfs for each memory section. The intent of the
    > patches is to reduce the number of sysfs directories created to
    > resolve a boot-time performance issue. On very large systems
    > boot time are getting very long (as seen on powerpc hardware)
    > due to the enormous number of sysfs directories being created.
    > On a system with 1 TB of memory we create ~63,000 directories.
    > For even larger systems boot times are being measured in hours.
    >
    > This set of patches allows for each directory created in sysfs
    > to cover more than one memory section. The default behavior for
    > sysfs directory creation is the same, in that each directory
    > represents a single memory section. A new file 'end_phys_index'
    > in each directory contains the physical_id of the last memory
    > section covered by the directory so that users can easily
    > determine the memory section range of a directory.

    I tested this on a POWER7 with 2TB memory and the boot time improved from
    greater than 6 hours (I gave up), to under 5 minutes. Nice!

    Tested-by: Anton Blanchard <anton@samba.org>

    Anton


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