Revision 494de90098784b8e2797598cefdd34188884ec2e authored by Mel Gorman on 03 July 2008, 04:27:51 UTC, committed by Linus Torvalds on 03 July 2008, 16:22:59 UTC
The non-NUMA case of build_zonelist_cache() would initialize the zlcache_ptr for both node_zonelists[] to NULL. Which is problematic, since non-NUMA only has a single node_zonelists[] entry, and trying to zero the non-existent second one just overwrote the nr_zones field instead. As kswapd uses this value to determine what reclaim work is necessary, the result is that kswapd never reclaims. This causes processes to stall frequently in low-memory situations as they always direct reclaim. This patch initialises zlcache_ptr correctly. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Tested-by: Dan Williams <dan.j.williams@intel.com> [ Simplified patch a bit ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent c461a97
ioremap.c
/*
* Re-map IO memory to kernel address space so that we can access it.
* This is needed for high PCI addresses that aren't mapped in the
* 640k-1MB IO memory area on PC's
*
* (C) Copyright 1995 1996 Linus Torvalds
*/
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>
static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
unsigned long end, unsigned long phys_addr, pgprot_t prot)
{
pte_t *pte;
unsigned long pfn;
pfn = phys_addr >> PAGE_SHIFT;
pte = pte_alloc_kernel(pmd, addr);
if (!pte)
return -ENOMEM;
do {
BUG_ON(!pte_none(*pte));
set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
pfn++;
} while (pte++, addr += PAGE_SIZE, addr != end);
return 0;
}
static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
unsigned long end, unsigned long phys_addr, pgprot_t prot)
{
pmd_t *pmd;
unsigned long next;
phys_addr -= addr;
pmd = pmd_alloc(&init_mm, pud, addr);
if (!pmd)
return -ENOMEM;
do {
next = pmd_addr_end(addr, end);
if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
return -ENOMEM;
} while (pmd++, addr = next, addr != end);
return 0;
}
static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
unsigned long end, unsigned long phys_addr, pgprot_t prot)
{
pud_t *pud;
unsigned long next;
phys_addr -= addr;
pud = pud_alloc(&init_mm, pgd, addr);
if (!pud)
return -ENOMEM;
do {
next = pud_addr_end(addr, end);
if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
return -ENOMEM;
} while (pud++, addr = next, addr != end);
return 0;
}
int ioremap_page_range(unsigned long addr,
unsigned long end, unsigned long phys_addr, pgprot_t prot)
{
pgd_t *pgd;
unsigned long start;
unsigned long next;
int err;
BUG_ON(addr >= end);
start = addr;
phys_addr -= addr;
pgd = pgd_offset_k(addr);
do {
next = pgd_addr_end(addr, end);
err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
if (err)
break;
} while (pgd++, addr = next, addr != end);
flush_cache_vmap(start, end);
return err;
}
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