x86: mm: Use 2GB memory block size on large-memory x86-64 systems
authorDaniel J Blueman <daniel@numascale.com>
Tue, 4 Nov 2014 08:29:44 +0000 (16:29 +0800)
committerThomas Gleixner <tglx@linutronix.de>
Tue, 4 Nov 2014 17:19:27 +0000 (18:19 +0100)
commitbdee237c0343a5d1a6cf72c7ea68e88338b26e08
tree1d8fa5903a9aa064e7904f5f2357b70f2a1ea209
parent63e7b6d90c1ebdb73d82eedb945b62ceedc3f963
x86: mm: Use 2GB memory block size on large-memory x86-64 systems

On large-memory x86-64 systems of 64GB or more with memory hot-plug
enabled, use a 2GB memory block size. Eg with 64GB memory, this reduces
the number of directories in /sys/devices/system/memory from 512 to 32,
making it more manageable, and reducing the creation time accordingly.

This caveat is that the memory can't be offlined (for hotplug or
otherwise) with the finer default 128MB granularity, but this is
unimportant due to the high memory densities generally used with such
large-memory systems, where eg a single DIMM is the order of 16GB.

Signed-off-by: Daniel J Blueman <daniel@numascale.com>
Cc: Steffen Persvold <sp@numascale.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1415089784-28779-4-git-send-email-daniel@numascale.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/mm/init_64.c