The patch titled
virtual memmap on sparsemem: generic virtual mem_map on sparsemem
has been removed from the -mm tree. Its filename was
virtual-memmap-on-sparsemem-v3-generic-virtual.patch
This patch was dropped because it is obsolete
------------------------------------------------------
Subject: virtual memmap on sparsemem: generic virtual mem_map on sparsemem
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
This patch implements of virtual mem_map on sparsemem. This includes only
arch independent part and depends on generic map/unmap in the kernel function
in this patch series.
Usual sparsemem(_extreme) have to do global table look up in
pfn_to_page()/page_to_pfn(), this seems a bit costly.
If an arch has enough address space to map all mem_map in linear, it is good
to map sprase mem_map as linear mem_map. This redcuces cost of
pfn_to_page()/page_to_pfn(). This concept is used by ia64's VIRTUAL_MEM_MAP.
pfn_valid() works as same as usual sparsemem.
callbacks to create vmem_map are used for using alloc_bootmem_node() for
allocationg pud/pmd/pte.
How to use:
fix struct page *mem_map's pointing address before calling sparse_init().
that's all.
Note:
I assumes that mem_map per each section is always aligned to PAGE_SIZE.
For example, ia64.
sizeof(struct page) = 56 && PAGES_PER_SECTION=65536. Then mem_map per
section is aligned to 56 * 65536 bytes.
#error will detect this.
Signed-off-by: KAMEZAWA Hiruyoki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Andy Whitcroft <apw@xxxxxxxxxxxx>
Cc: Dave Hansen <haveblue@xxxxxxxxxx>
Cc: Martin Bligh <mbligh@xxxxxxxxxx>
Cc: "Luck, Tony" <tony.luck@xxxxxxxxx>
Cc: Christoph Lameter <clameter@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/asm-generic/memory_model.h | 6 +
include/linux/mmzone.h | 9 +-
mm/Kconfig | 10 ++
mm/memory.c | 6 +
mm/sparse.c | 112 ++++++++++++++++++++++++++-
5 files changed, 138 insertions(+), 5 deletions(-)
diff -puN include/asm-generic/memory_model.h~virtual-memmap-on-sparsemem-v3-generic-virtual include/asm-generic/memory_model.h
--- a/include/asm-generic/memory_model.h~virtual-memmap-on-sparsemem-v3-generic-virtual
+++ a/include/asm-generic/memory_model.h
@@ -47,6 +47,11 @@
})
#elif defined(CONFIG_SPARSEMEM)
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+#define __page_to_pfn(pg) ((pg) - mem_map)
+#define __pfn_to_page(pfn) (mem_map + (pfn))
+#else
/*
* Note: section's mem_map is encorded to reflect its start_pfn.
* section[i].section_mem_map == mem_map's address - start_pfn;
@@ -62,6 +67,7 @@
struct mem_section *__sec = __pfn_to_section(__pfn); \
__section_mem_map_addr(__sec) + __pfn; \
})
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
#endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
diff -puN include/linux/mmzone.h~virtual-memmap-on-sparsemem-v3-generic-virtual include/linux/mmzone.h
--- a/include/linux/mmzone.h~virtual-memmap-on-sparsemem-v3-generic-virtual
+++ a/include/linux/mmzone.h
@@ -386,7 +386,7 @@ struct node_active_region {
};
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
-#ifndef CONFIG_DISCONTIGMEM
+#if !defined(CONFIG_DISCONTIGMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
/* The array of struct pages - for discontigmem use pgdat->lmem_map */
extern struct page *mem_map;
#endif
@@ -689,6 +689,13 @@ extern int __section_nr(struct mem_secti
#define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
#define SECTION_NID_SHIFT 2
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+#if (((BITS_PER_LONG/4) * PAGES_PER_SECTION) % PAGE_SIZE) != 0
+#error "PAGE_SIZE/SECTION_SIZE relationship is not suitable for vmem_map"
+#endif
+extern struct page* mem_map;
+#endif
+
static inline struct page *__section_mem_map_addr(struct mem_section *section)
{
unsigned long map = section->section_mem_map;
diff -puN mm/Kconfig~virtual-memmap-on-sparsemem-v3-generic-virtual mm/Kconfig
--- a/mm/Kconfig~virtual-memmap-on-sparsemem-v3-generic-virtual
+++ a/mm/Kconfig
@@ -112,12 +112,22 @@ config SPARSEMEM_EXTREME
def_bool y
depends on SPARSEMEM && !SPARSEMEM_STATIC
+config SPARSEMEM_VMEMMAP
+ bool "Virutally contiguous mem_map on sparsemem"
+ depends on SPARSEMEM && !SPARSEMEM_STATIC && ARCH_SPARSEMEM_VMEMMAP
+ help
+ This allows micro optimization to reduce costs of accessing
+ infrastructure of memory management.
+ But this consumes huge amount of virtual memory(not physical).
+ This option is selectable only if your arch supports it.
+
# eventually, we can have this option just 'select SPARSEMEM'
config MEMORY_HOTPLUG
bool "Allow for memory hot-add"
depends on SPARSEMEM || X86_64_ACPI_NUMA
depends on HOTPLUG && !SOFTWARE_SUSPEND && ARCH_ENABLE_MEMORY_HOTPLUG
depends on (IA64 || X86 || PPC64)
+ depends on !SPARSEMEM_VMEMMAP
comment "Memory hotplug is currently incompatible with Software Suspend"
depends on SPARSEMEM && HOTPLUG && SOFTWARE_SUSPEND
diff -puN mm/memory.c~virtual-memmap-on-sparsemem-v3-generic-virtual mm/memory.c
--- a/mm/memory.c~virtual-memmap-on-sparsemem-v3-generic-virtual
+++ a/mm/memory.c
@@ -69,6 +69,12 @@ EXPORT_SYMBOL(max_mapnr);
EXPORT_SYMBOL(mem_map);
#endif
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+/* for the virtual mem_map */
+struct page *mem_map;
+EXPORT_SYMBOL(mem_map);
+#endif
+
unsigned long num_physpages;
/*
* A number of key systems in x86 including ioremap() rely on the assumption
diff -puN mm/sparse.c~virtual-memmap-on-sparsemem-v3-generic-virtual mm/sparse.c
--- a/mm/sparse.c~virtual-memmap-on-sparsemem-v3-generic-virtual
+++ a/mm/sparse.c
@@ -9,6 +9,8 @@
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <asm/dma.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
/*
* Permanent SPARSEMEM data:
@@ -99,6 +101,106 @@ static inline int sparse_index_init(unsi
}
#endif
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+
+struct vmemmap_create_arg {
+ int section_nr;
+ int nid;
+};
+
+/* call backs for memory map */
+static int
+__init pte_alloc_vmemmap_boot(pmd_t *pmd, unsigned long addr, void *data)
+{
+ struct vmemmap_create_arg *arg = data;
+ void *pg = alloc_bootmem_pages_node(NODE_DATA(arg->nid), PAGE_SIZE);
+ BUG_ON(!pg);
+ pmd_populate_kernel(&init_mm, pmd, pg);
+ return 0;
+}
+static int
+__init pmd_alloc_vmemmap_boot(pud_t *pud, unsigned long addr, void *data)
+{
+ struct vmemmap_create_arg *arg = data;
+ void *pg = alloc_bootmem_pages_node(NODE_DATA(arg->nid), PAGE_SIZE);
+ BUG_ON(!pg);
+ pud_populate(&init_mm, pud, pg);
+ return 0;
+}
+
+static int
+__init pud_alloc_vmemmap_boot(pgd_t *pgd, unsigned long addr, void *data)
+{
+ struct vmemmap_create_arg *arg = data;
+ void *pg = alloc_bootmem_pages_node(NODE_DATA(arg->nid), PAGE_SIZE);
+ BUG_ON(!pg);
+ pgd_populate(&init_mm, pgd, pg);
+ return 0;
+}
+
+static int
+__init pte_set_vmemmap_boot(pte_t *pte, unsigned long addr, void *data)
+{
+ struct vmemmap_create_arg *arg = data;
+ struct mem_section *ms = __nr_to_section(arg->section_nr);
+ unsigned long pmap, vmap, section_pfn, pfn;
+
+ section_pfn = section_nr_to_pfn(arg->section_nr);
+ /* we already have mem_map in linear address space. calc it */
+
+ /* decode encoded value of base address. */
+ pmap = ms->section_mem_map & SECTION_MAP_MASK;
+ pmap = (unsigned long)((struct page *)pmap + section_pfn);
+ /* section's start */
+ vmap = (unsigned long)pfn_to_page(section_pfn);
+
+ pfn = (__pa(pmap) + (addr - vmap)) >> PAGE_SHIFT;
+ set_pte(pte, pfn_pte(pfn, PAGE_KERNEL));
+ return 0;
+}
+
+static int
+__init pte_clear_vmemmap(pte_t *pte, unsigned long addr, void *data)
+{
+ BUG();
+}
+
+struct gen_map_kern_ops vmemmap_boot_ops = {
+ .k_pte_set = pte_set_vmemmap_boot,
+ .k_pte_clear = pte_clear_vmemmap,
+ .k_pud_alloc = pud_alloc_vmemmap_boot,
+ .k_pmd_alloc = pmd_alloc_vmemmap_boot,
+ .k_pte_alloc = pte_alloc_vmemmap_boot,
+};
+
+static int
+__init map_virtual_mem_map(unsigned long section, int nid)
+{
+ struct vmemmap_create_arg arg;
+ unsigned long vmap_start, vmap_size;
+ vmap_start = (unsigned long)pfn_to_page(section_nr_to_pfn(section));
+ vmap_size = PAGES_PER_SECTION * sizeof(struct page);
+ arg.section_nr = section;
+ arg.nid = nid;
+
+ if (system_state == SYSTEM_BOOTING) {
+ map_generic_kernel(vmap_start, vmap_size, &vmemmap_boot_ops,
+ &arg);
+ } else {
+ BUG();
+ }
+ /* if bug, panic occurs.*/
+ return 0;
+}
+#else
+static int
+__init map_virtual_mem_map(unsigned long section, int nid)
+{
+ return 0;
+}
+#endif
+
+
/*
* Although written for the SPARSEMEM_EXTREME case, this happens
* to also work for the flat array case becase
@@ -115,7 +217,7 @@ int __section_nr(struct mem_section* ms)
continue;
if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
- break;
+ break;
}
return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
@@ -198,13 +300,14 @@ struct page *sparse_decode_mem_map(unsig
}
static int sparse_init_one_section(struct mem_section *ms,
- unsigned long pnum, struct page *mem_map)
+ unsigned long pnum, struct page *mem_map, int node)
{
if (!valid_section(ms))
return -EINVAL;
ms->section_mem_map &= ~SECTION_MAP_MASK;
ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum);
+ map_virtual_mem_map(pnum, node);
return 1;
}
@@ -284,7 +387,8 @@ void sparse_init(void)
map = sparse_early_mem_map_alloc(pnum);
if (!map)
continue;
- sparse_init_one_section(__nr_to_section(pnum), pnum, map);
+ sparse_init_one_section(__nr_to_section(pnum), pnum, map,
+ sparse_early_nid(__nr_to_section(pnum)));
}
}
@@ -319,7 +423,7 @@ int sparse_add_one_section(struct zone *
}
ms->section_mem_map |= SECTION_MARKED_PRESENT;
- ret = sparse_init_one_section(ms, section_nr, memmap);
+ ret = sparse_init_one_section(ms, section_nr, memmap, pgdat->node_id);
out:
pgdat_resize_unlock(pgdat, &flags);
_
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
virtual-memmap-on-sparsemem-v3-generic-virtual.patch
virtual-memmap-on-sparsemem-v3-generic-virtual-fix.patch
virtual-memmap-on-sparsemem-v3-static-virtual.patch
virtual-memmap-on-sparsemem-v3-static-virtual-update.patch
virtual-memmap-on-sparsemem-v3-ia64-support.patch
virtual-memmap-on-sparsemem-v3-ia64-support-update.patch
mm-only-sched-add-a-few-scheduler-event-counters.patch
reiser4-hardirq-include-fix.patch
-
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