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c9e3735359
linux/arch/s390/mm/init.c
Heiko Carstens c9e3735359 [PATCH] s390: fix memory holes and cleanup setup_arch 
The memory setup didn't take care of memory holes and this makes the memory
management think there would be more memory available than there is in
reality.  That causes the OOM killer to kill processes even if there is enough
memory left that can be written to the swap space.

The patch fixes this by using free_area_init_node with an array of memory
holes instead of free_area_init.  Further the patch cleans up the code in
setup.c by splitting setup_arch into smaller pieces.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:58:57 -07:00

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/*
* arch/s390/mm/init.c
*
* S390 version
* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Hartmut Penner (hp@de.ibm.com)
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1995 Linus Torvalds
*/
#include <linux/config.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/bootmem.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/lowcore.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
char empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
void diag10(unsigned long addr)
{
if (addr >= 0x7ff00000)
return;
#ifdef __s390x__
asm volatile (
" sam31\n"
" diag %0,%0,0x10\n"
"0: sam64\n"
".section __ex_table,\"a\"\n"
" .align 8\n"
" .quad 0b, 0b\n"
".previous\n"
: : "a" (addr));
#else
asm volatile (
" diag %0,%0,0x10\n"
"0:\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 0b, 0b\n"
".previous\n"
: : "a" (addr));
#endif
}
void show_mem(void)
{
int i, total = 0, reserved = 0;
int shared = 0, cached = 0;
printk("Mem-info:\n");
show_free_areas();
printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
i = max_mapnr;
while (i-- > 0) {
total++;
if (PageReserved(mem_map+i))
reserved++;
else if (PageSwapCache(mem_map+i))
cached++;
else if (page_count(mem_map+i))
shared += page_count(mem_map+i) - 1;
}
printk("%d pages of RAM\n",total);
printk("%d reserved pages\n",reserved);
printk("%d pages shared\n",shared);
printk("%d pages swap cached\n",cached);
}
/* References to section boundaries */
extern unsigned long _text;
extern unsigned long _etext;
extern unsigned long _edata;
extern unsigned long __bss_start;
extern unsigned long _end;
extern unsigned long __init_begin;
extern unsigned long __init_end;
extern unsigned long __initdata zholes_size[];
/*
* paging_init() sets up the page tables
*/
#ifndef CONFIG_ARCH_S390X
void __init paging_init(void)
{
pgd_t * pg_dir;
pte_t * pg_table;
pte_t pte;
int i;
unsigned long tmp;
unsigned long pfn = 0;
unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
static const int ssm_mask = 0x04000000L;
/* unmap whole virtual address space */
pg_dir = swapper_pg_dir;
for (i=0;i<KERNEL_PGD_PTRS;i++)
pmd_clear((pmd_t*)pg_dir++);
/*
* map whole physical memory to virtual memory (identity mapping)
*/
pg_dir = swapper_pg_dir;
while (pfn < max_low_pfn) {
/*
* pg_table is physical at this point
*/
pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
pg_dir->pgd0 = (_PAGE_TABLE | __pa(pg_table));
pg_dir->pgd1 = (_PAGE_TABLE | (__pa(pg_table)+1024));
pg_dir->pgd2 = (_PAGE_TABLE | (__pa(pg_table)+2048));
pg_dir->pgd3 = (_PAGE_TABLE | (__pa(pg_table)+3072));
pg_dir++;
for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
pte = pfn_pte(pfn, PAGE_KERNEL);
if (pfn >= max_low_pfn)
pte_clear(&init_mm, 0, &pte);
set_pte(pg_table, pte);
pfn++;
}
}
S390_lowcore.kernel_asce = pgdir_k;
/* enable virtual mapping in kernel mode */
__asm__ __volatile__(" LCTL 1,1,%0\n"
" LCTL 7,7,%0\n"
" LCTL 13,13,%0\n"
" SSM %1"
: : "m" (pgdir_k), "m" (ssm_mask));
local_flush_tlb();
{
unsigned long zones_size[MAX_NR_ZONES];
memset(zones_size, 0, sizeof(zones_size));
zones_size[ZONE_DMA] = max_low_pfn;
free_area_init_node(0, &contig_page_data, zones_size,
__pa(PAGE_OFFSET) >> PAGE_SHIFT,
zholes_size);
}
return;
}
#else /* CONFIG_ARCH_S390X */
void __init paging_init(void)
{
pgd_t * pg_dir;
pmd_t * pm_dir;
pte_t * pt_dir;
pte_t pte;
int i,j,k;
unsigned long pfn = 0;
unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
_KERN_REGION_TABLE;
static const int ssm_mask = 0x04000000L;
unsigned long zones_size[MAX_NR_ZONES];
unsigned long dma_pfn, high_pfn;
memset(zones_size, 0, sizeof(zones_size));
dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
high_pfn = max_low_pfn;
if (dma_pfn > high_pfn)
zones_size[ZONE_DMA] = high_pfn;
else {
zones_size[ZONE_DMA] = dma_pfn;
zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
}
/* Initialize mem_map[]. */
free_area_init_node(0, &contig_page_data, zones_size,
__pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
/*
* map whole physical memory to virtual memory (identity mapping)
*/
pg_dir = swapper_pg_dir;
for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
if (pfn >= max_low_pfn) {
pgd_clear(pg_dir);
continue;
}
pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
pgd_populate(&init_mm, pg_dir, pm_dir);
for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
if (pfn >= max_low_pfn) {
pmd_clear(pm_dir);
continue;
}
pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
pte = pfn_pte(pfn, PAGE_KERNEL);
if (pfn >= max_low_pfn) {
pte_clear(&init_mm, 0, &pte);
continue;
}
set_pte(pt_dir, pte);
pfn++;
}
}
}
S390_lowcore.kernel_asce = pgdir_k;
/* enable virtual mapping in kernel mode */
__asm__ __volatile__("lctlg 1,1,%0\n\t"
"lctlg 7,7,%0\n\t"
"lctlg 13,13,%0\n\t"
"ssm %1"
: :"m" (pgdir_k), "m" (ssm_mask));
local_flush_tlb();
return;
}
#endif /* CONFIG_ARCH_S390X */
void __init mem_init(void)
{
unsigned long codesize, reservedpages, datasize, initsize;
max_mapnr = num_physpages = max_low_pfn;
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
/* clear the zero-page */
memset(empty_zero_page, 0, PAGE_SIZE);
/* this will put all low memory onto the freelists */
totalram_pages += free_all_bootmem();
reservedpages = 0;
codesize = (unsigned long) &_etext - (unsigned long) &_text;
datasize = (unsigned long) &_edata - (unsigned long) &_etext;
initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
max_mapnr << (PAGE_SHIFT-10),
codesize >> 10,
reservedpages << (PAGE_SHIFT-10),
datasize >>10,
initsize >> 10);
}
void free_initmem(void)
{
unsigned long addr;
addr = (unsigned long)(&__init_begin);
for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
set_page_count(virt_to_page(addr), 1);
free_page(addr);
totalram_pages++;
}
printk ("Freeing unused kernel memory: %ldk freed\n",
((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
if (start < end)
printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
for (; start < end; start += PAGE_SIZE) {
ClearPageReserved(virt_to_page(start));
set_page_count(virt_to_page(start), 1);
free_page(start);
totalram_pages++;
}
}
#endif
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