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Should have been part of r35023: Introduction of the vm_page::modified flag.

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git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35024 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Ingo Weinhold 2010-01-12 01:24:40 +00:00
parent 829f302836
commit 3b8c056da0
2 changed files with 19 additions and 22 deletions
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7
headers/private/kernel/vm/vm_types.h
View File

@ -94,11 +94,12 @@ struct vm_page {
vint32 accessing_thread;
#endif
uint8 is_dummy : 1;
uint8 state : 3;
uint8 busy_writing : 1;
bool is_dummy : 1;
bool busy_writing : 1;
// used in VMAnonymousCache::Merge()
uint8 unused : 3;
bool modified : 1;
uint8 unused : 2;
int8 usage_count;
uint16 wired_count;

34
src/system/kernel/vm/vm.cpp
View File

@ -1974,6 +1974,9 @@ virtual_page_address(VMArea* area, vm_page* page)
bool
vm_test_map_modification(vm_page* page)
{
if (page->modified)
return true;
vm_page_mappings::Iterator iterator = page->mappings.GetIterator();
vm_page_mapping* mapping;
while ((mapping = iterator.Next()) != NULL) {
@ -2001,7 +2004,7 @@ int32
vm_test_map_activation(vm_page* page, bool* _modified)
{
int32 activation = 0;
bool modified = false;
bool modified = page->modified;
vm_page_mappings::Iterator iterator = page->mappings.GetIterator();
vm_page_mapping* mapping;
@ -2034,6 +2037,9 @@ vm_test_map_activation(vm_page* page, bool* _modified)
void
vm_clear_map_flags(vm_page* page, uint32 flags)
{
if ((flags & PAGE_MODIFIED) != 0)
page->modified = false;
vm_page_mappings::Iterator iterator = page->mappings.GetIterator();
vm_page_mapping* mapping;
while ((mapping = iterator.Next()) != NULL) {
@ -2056,6 +2062,8 @@ void
vm_remove_all_page_mappings(vm_page* page, uint32* _flags)
{
uint32 accumulatedFlags = 0;
if (page->modified)
accumulatedFlags |= PAGE_MODIFIED;
vm_page_mappings queue;
queue.MoveFrom(&page->mappings);
@ -2095,7 +2103,7 @@ vm_remove_all_page_mappings(vm_page* page, uint32* _flags)
/*! If \a preserveModified is \c true, the caller must hold the lock of the
page's cache and the page must not be busy.
page's cache.
*/
bool
vm_unmap_page(VMArea* area, addr_t virtualAddress, bool preserveModified)
@ -2127,8 +2135,8 @@ vm_unmap_page(VMArea* area, addr_t virtualAddress, bool preserveModified)
map->ops->flush(map);
status = map->ops->query(map, virtualAddress, &physicalAddress, &flags);
if ((flags & PAGE_MODIFIED) != 0 && page->state != PAGE_STATE_MODIFIED)
vm_page_set_state(page, PAGE_STATE_MODIFIED);
if ((flags & PAGE_MODIFIED) != 0)
page->modified = true;
}
vm_page_mapping* mapping = NULL;
@ -2162,9 +2170,7 @@ vm_unmap_page(VMArea* area, addr_t virtualAddress, bool preserveModified)
/*! If \a preserveModified is \c true, the caller must hold the lock of all
mapped pages' caches and none of the pages must be busy.
TODO: Particularly the latter is very inconvenient. See the TODOs below for
reasons for this requirement.
mapped pages' caches.
*/
status_t
vm_unmap_pages(VMArea* area, addr_t base, size_t size, bool preserveModified)
@ -2214,18 +2220,8 @@ vm_unmap_pages(VMArea* area, addr_t base, size_t size, bool preserveModified)
physicalAddress);
}
DEBUG_PAGE_ACCESS_START(page);
// TODO: No guarantee for that. See below.
if ((flags & PAGE_MODIFIED) != 0
&& page->state != PAGE_STATE_MODIFIED) {
vm_page_set_state(page, PAGE_STATE_MODIFIED);
// TODO: We are only allowed to do this, if (a) we have also
// locked the cache and (b) the page is not busy! Not doing
// it is problematic, too, since we'd lose information.
}
DEBUG_PAGE_ACCESS_END(page);
if ((flags & PAGE_MODIFIED) != 0)
page->modified = true;
}
}