Re: [git pull] "big box" x86 changes, bootmem/sparsemem

From: Ingo Molnar
Date: Sat Apr 26 2008 - 16:07:41 EST



* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> Having preprocessor conditionals that mix things up is not an excuse,
> and it might be an argument for not doing the conditional that way (ie
> maybe just make sure that when NUMA is not on, nid/next_nid will
> always be different, and in a way that the compiler can perhaps see
> statically that they are different - so that you can have the
> conditional there even with NUMA off, but the compiler will just fold
> it away?).

for now i cleaned it up the way below, but i also queued up a cleanup
patch separately (second patch attached below) that removes the #ifdef.
The current version is the tested one so i'll keep that in the tree and
will treat the cleanup separately.

Ingo

------------------------>
Subject: x86_64: make reserve_bootmem_generic() use new reserve_bootmem()
From: Yinghai Lu <yhlu.kernel@xxxxxxxxx>
Date: Tue, 18 Mar 2008 12:50:21 -0700

"mm: make reserve_bootmem can crossed the nodes" provides new
reserve_bootmem(), let reserve_bootmem_generic() use that.

reserve_bootmem_generic() is used to reserve initramdisk, so this way
we can make sure even when bootloader or kexec load ranges cross the
node memory boundaries, reserve_bootmem still works.

Signed-off-by: Yinghai Lu <yhlu.kernel@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/mm/init_64.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

Index: linux-x86.q/arch/x86/mm/init_64.c
===================================================================
--- linux-x86.q.orig/arch/x86/mm/init_64.c
+++ linux-x86.q/arch/x86/mm/init_64.c
@@ -810,7 +810,7 @@ void free_initrd_mem(unsigned long start
void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
{
#ifdef CONFIG_NUMA
- int nid = phys_to_nid(phys);
+ int nid, next_nid;
#endif
unsigned long pfn = phys >> PAGE_SHIFT;

@@ -829,10 +829,16 @@ void __init reserve_bootmem_generic(unsi

/* Should check here against the e820 map to avoid double free */
#ifdef CONFIG_NUMA
- reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
+ nid = phys_to_nid(phys);
+ next_nid = phys_to_nid(phys + len - 1);
+ if (nid == next_nid)
+ reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
+ else
+ reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
#else
reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
#endif
+
if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
dma_reserve += len / PAGE_SIZE;
set_dma_reserve(dma_reserve);

------------->
Subject: x86: reserve bootmem cleanup
From: Ingo Molnar <mingo@xxxxxxx>
Date: Sat Apr 26 21:50:20 CEST 2008

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/mm/init_64.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)

Index: linux-x86.q/arch/x86/mm/init_64.c
===================================================================
--- linux-x86.q.orig/arch/x86/mm/init_64.c
+++ linux-x86.q/arch/x86/mm/init_64.c
@@ -810,10 +810,8 @@ void free_initrd_mem(unsigned long start

void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
{
-#ifdef CONFIG_NUMA
- int nid, next_nid;
-#endif
unsigned long pfn = phys >> PAGE_SHIFT;
+ int nid, next_nid;

if (pfn >= end_pfn) {
/*
@@ -829,16 +827,12 @@ void __init reserve_bootmem_generic(unsi
}

/* Should check here against the e820 map to avoid double free */
-#ifdef CONFIG_NUMA
nid = phys_to_nid(phys);
next_nid = phys_to_nid(phys + len - 1);
if (nid == next_nid)
reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
else
reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
-#else
- reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
-#endif

if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
dma_reserve += len / PAGE_SIZE;
--
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