From 885e821211706c988f75d044ed281c17d0949f5e Mon Sep 17 00:00:00 2001
From: Gleb Natapov <gleb@cloudius-systems.com>
Date: Tue, 25 Mar 2014 10:15:45 +0200
Subject: [PATCH] mmu: pass type of a page fault (r/w) to a page allocator
Page allocation may behave differently depending on a type of a fault.
Read fault may return ARC page, but write may do cow for instance.
Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>
---
core/mmu.cc | 34 ++++++++++++++++++----------------
1 file changed, 18 insertions(+), 16 deletions(-)
diff --git a/core/mmu.cc b/core/mmu.cc
index 4d7ae9ac5..465be1f55 100644
--- a/core/mmu.cc
+++ b/core/mmu.cc
@@ -173,8 +173,8 @@ void split_large_page(hw_ptep ptep, unsigned level)
}
struct page_allocator {
- virtual void* alloc(uintptr_t offset, hw_ptep ptep) = 0;
- virtual void* alloc(size_t size, uintptr_t offset, hw_ptep ptep) = 0;
+ virtual void* alloc(uintptr_t offset, hw_ptep ptep, bool write) = 0;
+ virtual void* alloc(size_t size, uintptr_t offset, hw_ptep ptep, bool write) = 0;
virtual void free(void *addr, uintptr_t offset, hw_ptep ptep) = 0;
virtual void free(void *addr, size_t size, uintptr_t offset, hw_ptep ptep) = 0;
virtual void finalize() = 0;
@@ -465,19 +465,20 @@ class populate : public vma_operation<allocate_intermediate_opt::yes, skip_empty
private:
page_allocator* _page_provider;
unsigned int perm;
+ bool _write;
bool _map_dirty;
pt_element dirty(pt_element pte) {
pte.set_dirty(_map_dirty);
return pte;
}
public:
- populate(page_allocator* pops, unsigned int perm, bool map_dirty = true) :
- _page_provider(pops), perm(perm), _map_dirty(map_dirty) { }
+ populate(page_allocator* pops, unsigned int perm, bool write = false, bool map_dirty = true) :
+ _page_provider(pops), perm(perm), _write(write), _map_dirty(map_dirty) { }
void small_page(hw_ptep ptep, uintptr_t offset){
if (!ptep.read().empty()) {
return;
}
- phys page = virt_to_phys(_page_provider->alloc(offset, ptep));
+ phys page = virt_to_phys(_page_provider->alloc(offset, ptep, _write));
if (!ptep.compare_exchange(make_empty_pte(), dirty(make_normal_pte(page, perm)))) {
_page_provider->free(phys_to_virt(page), offset, ptep);
} else {
@@ -489,7 +490,7 @@ public:
if (!pte.empty()) {
return true;
}
- void *vpage = _page_provider->alloc(huge_page_size, offset, ptep);
+ void *vpage = _page_provider->alloc(huge_page_size, offset, ptep, _write);
if (!vpage) {
return false;
}
@@ -507,7 +508,8 @@ public:
template <account_opt Account = account_opt::no>
class populate_small : public populate<Account> {
public:
- populate_small(page_allocator* pops, unsigned int perm, bool map_dirty = true) : populate<Account>(pops, perm, map_dirty) { }
+ populate_small(page_allocator* pops, unsigned int perm, bool write = false, bool map_dirty = true) :
+ populate<Account>(pops, perm, write, map_dirty) { }
bool huge_page(hw_ptep ptep, uintptr_t offset) {
assert(0);
return false;
@@ -861,10 +863,10 @@ private:
return addr;
}
public:
- virtual void* alloc(uintptr_t offset, hw_ptep ptep) override {
+ virtual void* alloc(uintptr_t offset, hw_ptep ptep, bool write) override {
return fill(memory::alloc_page(), offset, page_size);
}
- virtual void* alloc(size_t size, uintptr_t offset, hw_ptep ptep) override {
+ virtual void* alloc(size_t size, uintptr_t offset, hw_ptep ptep, bool write) override {
return fill(memory::alloc_huge_page(size), offset, size);
}
virtual void free(void *addr, uintptr_t offset, hw_ptep ptep) override {
@@ -923,10 +925,10 @@ public:
map_file_page_mmap(file *file, off_t off) : _file(file), _map_offset(off) {}
virtual ~map_file_page_mmap() {};
- virtual void* alloc(uintptr_t offset, hw_ptep ptep) override {
- return alloc(page_size, offset, ptep);
+ virtual void* alloc(uintptr_t offset, hw_ptep ptep, bool write) override {
+ return alloc(page_size, offset, ptep, write);
}
- virtual void* alloc(size_t size, uintptr_t offset, hw_ptep ptep) override {
+ virtual void* alloc(size_t size, uintptr_t offset, hw_ptep ptep, bool write) override {
return _file->get_page(offset + _map_offset, size, ptep);
}
virtual void free(void *addr, uintptr_t offset, hw_ptep ptep) override {
@@ -1041,12 +1043,12 @@ void vcleanup(void* addr, size_t size)
}
template<account_opt Account = account_opt::no>
-ulong populate_vma(vma *vma, void *v, size_t size)
+ulong populate_vma(vma *vma, void *v, size_t size, bool write = false)
{
page_allocator *map = vma->page_ops();
auto total = vma->has_flags(mmap_small) ?
- vma->operate_range(populate_small<Account>(map, vma->perm(), vma->map_dirty()), v, size) :
- vma->operate_range(populate<Account>(map, vma->perm(), vma->map_dirty()), v, size);
+ vma->operate_range(populate_small<Account>(map, vma->perm(), write, vma->map_dirty()), v, size) :
+ vma->operate_range(populate<Account>(map, vma->perm(), write, vma->map_dirty()), v, size);
map->finalize();
return total;
@@ -1301,7 +1303,7 @@ void vma::fault(uintptr_t addr, exception_frame *ef)
size = page_size;
}
- auto total = populate_vma<account_opt::yes>(this, (void*)addr, size);
+ auto total = populate_vma<account_opt::yes>(this, (void*)addr, size, ef->error_code & page_fault_write);
if (_flags & mmap_jvm_heap) {
memory::stats::on_jvm_heap_alloc(total);
--
GitLab