Yes, there has been a bit of code churn in arch/x86/mm/init_64.c around
this area. I will get the modified patches for each of your replies
late next week as soon as I get back.
Thanks,
Mike
On 6/27/2018 7:05 PM, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f642fb5864a6e3645edce6f85ffe7b44d5e9b990 Mon Sep 17 00:00:00 2001
From: "mike.travis@xxxxxxx" <mike.travis@xxxxxxx>
Date: Thu, 24 May 2018 15:17:12 -0500
Subject: [PATCH] x86/platform/UV: Add adjustable set memory block size
function
Add a new function to "adjust" the current fixed UV memory block size
of 2GB so it can be changed to a different physical boundary. This is
out of necessity so arch dependent code can accommodate specific BIOS
requirements which can align these new PMEM modules at less than the
default boundaries.
A "set order" type of function was used to insure that the memory block
size will be a power of two value without requiring a validity check.
64GB was chosen as the upper limit for memory block size values to
accommodate upcoming 4PB systems which have 6 more bits of physical
address space (46 becoming 52).
Signed-off-by: Mike Travis <mike.travis@xxxxxxx>
Reviewed-by: Andrew Banman <andrew.banman@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Dimitri Sivanich <dimitri.sivanich@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Russ Anderson <russ.anderson@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: dan.j.williams@xxxxxxxxx
Cc: jgross@xxxxxxxx
Cc: kirill.shutemov@xxxxxxxxxxxxxxx
Cc: mhocko@xxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/lkml/20180524201711.609546602@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 0a400606dea0..20d8bf5fbceb 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1350,16 +1350,28 @@ int kern_addr_valid(unsigned long addr)
/* Amount of ram needed to start using large blocks */
#define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
+/* Adjustable memory block size */
+static unsigned long set_memory_block_size;
+int __init set_memory_block_size_order(unsigned int order)
+{
+ unsigned long size = 1UL << order;
+
+ if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
+ return -EINVAL;
+
+ set_memory_block_size = size;
+ return 0;
+}
+
static unsigned long probe_memory_block_size(void)
{
unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
unsigned long bz;
- /* If this is UV system, always set 2G block size */
- if (is_uv_system()) {
- bz = MAX_BLOCK_SIZE;
+ /* If memory block size has been set, then use it */
+ bz = set_memory_block_size;
+ if (bz)
goto done;
- }
/* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 31ca3e28b0eb..a6ddefc60517 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -38,6 +38,7 @@ struct memory_block {
int arch_get_memory_phys_device(unsigned long start_pfn);
unsigned long memory_block_size_bytes(void);
+int set_memory_block_size_order(unsigned int order);
/* These states are exposed to userspace as text strings in sysfs */
#define MEM_ONLINE (1<<0) /* exposed to userspace */
