Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-13 07:31:45 +00:00
Code Issues Packages Projects Releases Wiki Activity

x86: mm: Use 2GB memory block size on large-memory x86-64 systems

Browse Source 
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>
This commit is contained in:
Daniel J Blueman 2014-11-04 16:29:44 +08:00 committed by Thomas Gleixner
parent 63e7b6d90c
commit bdee237c03
1 changed files with 2 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/x86/mm/init_64.c
View File

@ -52,7 +52,6 @@
#include <asm/numa.h> #include <asm/numa.h>
#include <asm/cacheflush.h> #include <asm/cacheflush.h>
#include <asm/init.h> #include <asm/init.h>
#include <asm/uv/uv.h>
#include <asm/setup.h> #include <asm/setup.h>
#include "mm_internal.h" #include "mm_internal.h"
@ -1247,12 +1246,10 @@ static unsigned long probe_memory_block_size(void)
/* start from 2g */ /* start from 2g */
unsigned long bz = 1UL<<31; unsigned long bz = 1UL<<31;
#ifdef CONFIG_X86_UV if (totalram_pages >= (64ULL << (30 - PAGE_SHIFT))) {
if (is_uv_system()) { pr_info("Using 2GB memory block size for large-memory system\n");
printk(KERN_INFO "UV: memory block size 2GB\n");
return 2UL * 1024 * 1024 * 1024; return 2UL * 1024 * 1024 * 1024;
} }
#endif
/* less than 64g installed */ /* less than 64g installed */
if ((max_pfn << PAGE_SHIFT) < (16UL << 32)) if ((max_pfn << PAGE_SHIFT) < (16UL << 32))