linux/arch/ia64/mm/contig.c
Robin Holt fde740e4dd [IA64] Percpu quicklist for combined allocator for pgd/pmd/pte.
This patch introduces using the quicklists for pgd, pmd, and pte levels
by combining the alloc and free functions into a common set of routines.
This greatly simplifies the reading of this header file.

This patch is simple but necessary for large numa configurations.
It simply ensures that only pages from the local node are added to a
cpus quicklist.  This prevents the trapping of pages on a remote nodes
quicklist by starting a process, touching a large number of pages to
fill pmd and pte entries, migrating to another node, and then unmapping
or exiting.  With those conditions, the pages get trapped and if the
machine has more than 100 nodes of the same size, the calculation of
the pgtable high water mark will be larger than any single node so page
table cache flushing will never occur.

I ran lmbench lat_proc fork and lat_proc exec on a zx1 with and without
this patch and did not notice any change.

On an sn2 machine, there was a slight improvement which is possibly
due to pages from other nodes trapped on the test node before starting
the run.  I did not investigate further.

This patch shrinks the quicklist based upon free memory on the node
instead of the high/low water marks.  I have written it to enable
preemption periodically and recalculate the amount to shrink every time
we have freed enough pages that the quicklist size should have grown.
I rescan the nodes zones each pass because other processess may be
draining node memory at the same time as we are adding.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-04-25 13:13:16 -07:00

300 lines
7.4 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1998-2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
* Stephane Eranian <eranian@hpl.hp.com>
* Copyright (C) 2000, Rohit Seth <rohit.seth@intel.com>
* Copyright (C) 1999 VA Linux Systems
* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
* Copyright (C) 2003 Silicon Graphics, Inc. All rights reserved.
*
* Routines used by ia64 machines with contiguous (or virtually contiguous)
* memory.
*/
#include <linux/config.h>
#include <linux/bootmem.h>
#include <linux/efi.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <asm/meminit.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/sections.h>
#include <asm/mca.h>
#ifdef CONFIG_VIRTUAL_MEM_MAP
static unsigned long num_dma_physpages;
#endif
/**
* show_mem - display a memory statistics summary
*
* Just walks the pages in the system and describes where they're allocated.
*/
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) {
if (!pfn_valid(i))
continue;
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);
printk("%ld pages in page table cache\n",
pgtable_quicklist_total_size());
}
/* physical address where the bootmem map is located */
unsigned long bootmap_start;
/**
* find_max_pfn - adjust the maximum page number callback
* @start: start of range
* @end: end of range
* @arg: address of pointer to global max_pfn variable
*
* Passed as a callback function to efi_memmap_walk() to determine the highest
* available page frame number in the system.
*/
int
find_max_pfn (unsigned long start, unsigned long end, void *arg)
{
unsigned long *max_pfnp = arg, pfn;
pfn = (PAGE_ALIGN(end - 1) - PAGE_OFFSET) >> PAGE_SHIFT;
if (pfn > *max_pfnp)
*max_pfnp = pfn;
return 0;
}
/**
* find_bootmap_location - callback to find a memory area for the bootmap
* @start: start of region
* @end: end of region
* @arg: unused callback data
*
* Find a place to put the bootmap and return its starting address in
* bootmap_start. This address must be page-aligned.
*/
int
find_bootmap_location (unsigned long start, unsigned long end, void *arg)
{
unsigned long needed = *(unsigned long *)arg;
unsigned long range_start, range_end, free_start;
int i;
#if IGNORE_PFN0
if (start == PAGE_OFFSET) {
start += PAGE_SIZE;
if (start >= end)
return 0;
}
#endif
free_start = PAGE_OFFSET;
for (i = 0; i < num_rsvd_regions; i++) {
range_start = max(start, free_start);
range_end = min(end, rsvd_region[i].start & PAGE_MASK);
free_start = PAGE_ALIGN(rsvd_region[i].end);
if (range_end <= range_start)
continue; /* skip over empty range */
if (range_end - range_start >= needed) {
bootmap_start = __pa(range_start);
return -1; /* done */
}
/* nothing more available in this segment */
if (range_end == end)
return 0;
}
return 0;
}
/**
* find_memory - setup memory map
*
* Walk the EFI memory map and find usable memory for the system, taking
* into account reserved areas.
*/
void
find_memory (void)
{
unsigned long bootmap_size;
reserve_memory();
/* first find highest page frame number */
max_pfn = 0;
efi_memmap_walk(find_max_pfn, &max_pfn);
/* how many bytes to cover all the pages */
bootmap_size = bootmem_bootmap_pages(max_pfn) << PAGE_SHIFT;
/* look for a location to hold the bootmap */
bootmap_start = ~0UL;
efi_memmap_walk(find_bootmap_location, &bootmap_size);
if (bootmap_start == ~0UL)
panic("Cannot find %ld bytes for bootmap\n", bootmap_size);
bootmap_size = init_bootmem(bootmap_start >> PAGE_SHIFT, max_pfn);
/* Free all available memory, then mark bootmem-map as being in use. */
efi_memmap_walk(filter_rsvd_memory, free_bootmem);
reserve_bootmem(bootmap_start, bootmap_size);
find_initrd();
}
#ifdef CONFIG_SMP
/**
* per_cpu_init - setup per-cpu variables
*
* Allocate and setup per-cpu data areas.
*/
void *
per_cpu_init (void)
{
void *cpu_data;
int cpu;
/*
* get_free_pages() cannot be used before cpu_init() done. BSP
* allocates "NR_CPUS" pages for all CPUs to avoid that AP calls
* get_zeroed_page().
*/
if (smp_processor_id() == 0) {
cpu_data = __alloc_bootmem(PERCPU_PAGE_SIZE * NR_CPUS,
PERCPU_PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
for (cpu = 0; cpu < NR_CPUS; cpu++) {
memcpy(cpu_data, __phys_per_cpu_start, __per_cpu_end - __per_cpu_start);
__per_cpu_offset[cpu] = (char *) cpu_data - __per_cpu_start;
cpu_data += PERCPU_PAGE_SIZE;
per_cpu(local_per_cpu_offset, cpu) = __per_cpu_offset[cpu];
}
}
return __per_cpu_start + __per_cpu_offset[smp_processor_id()];
}
#endif /* CONFIG_SMP */
static int
count_pages (u64 start, u64 end, void *arg)
{
unsigned long *count = arg;
*count += (end - start) >> PAGE_SHIFT;
return 0;
}
#ifdef CONFIG_VIRTUAL_MEM_MAP
static int
count_dma_pages (u64 start, u64 end, void *arg)
{
unsigned long *count = arg;
if (start < MAX_DMA_ADDRESS)
*count += (min(end, MAX_DMA_ADDRESS) - start) >> PAGE_SHIFT;
return 0;
}
#endif
/*
* Set up the page tables.
*/
void
paging_init (void)
{
unsigned long max_dma;
unsigned long zones_size[MAX_NR_ZONES];
#ifdef CONFIG_VIRTUAL_MEM_MAP
unsigned long zholes_size[MAX_NR_ZONES];
unsigned long max_gap;
#endif
/* initialize mem_map[] */
memset(zones_size, 0, sizeof(zones_size));
num_physpages = 0;
efi_memmap_walk(count_pages, &num_physpages);
max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
#ifdef CONFIG_VIRTUAL_MEM_MAP
memset(zholes_size, 0, sizeof(zholes_size));
num_dma_physpages = 0;
efi_memmap_walk(count_dma_pages, &num_dma_physpages);
if (max_low_pfn < max_dma) {
zones_size[ZONE_DMA] = max_low_pfn;
zholes_size[ZONE_DMA] = max_low_pfn - num_dma_physpages;
} else {
zones_size[ZONE_DMA] = max_dma;
zholes_size[ZONE_DMA] = max_dma - num_dma_physpages;
if (num_physpages > num_dma_physpages) {
zones_size[ZONE_NORMAL] = max_low_pfn - max_dma;
zholes_size[ZONE_NORMAL] =
((max_low_pfn - max_dma) -
(num_physpages - num_dma_physpages));
}
}
max_gap = 0;
efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
if (max_gap < LARGE_GAP) {
vmem_map = (struct page *) 0;
free_area_init_node(0, &contig_page_data, zones_size, 0,
zholes_size);
} else {
unsigned long map_size;
/* allocate virtual_mem_map */
map_size = PAGE_ALIGN(max_low_pfn * sizeof(struct page));
vmalloc_end -= map_size;
vmem_map = (struct page *) vmalloc_end;
efi_memmap_walk(create_mem_map_page_table, NULL);
NODE_DATA(0)->node_mem_map = vmem_map;
free_area_init_node(0, &contig_page_data, zones_size,
0, zholes_size);
printk("Virtual mem_map starts at 0x%p\n", mem_map);
}
#else /* !CONFIG_VIRTUAL_MEM_MAP */
if (max_low_pfn < max_dma)
zones_size[ZONE_DMA] = max_low_pfn;
else {
zones_size[ZONE_DMA] = max_dma;
zones_size[ZONE_NORMAL] = max_low_pfn - max_dma;
}
free_area_init(zones_size);
#endif /* !CONFIG_VIRTUAL_MEM_MAP */
zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));
}