RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 13:28:11 +00:00
Code Issues Activity Actions

Kernel: Don't remap all regions from Region::remap_vmobject_page()

Browse source 
When handling a page fault, we only need to remap the faulting region in
the current process. There's no need to traverse *all* regions that map
the same VMObject and remap them cross-process as well.

Those other regions will get remapped lazily by their own page fault
handlers eventually. Or maybe they won't and we avoided some work. :^)
This commit is contained in:
Andreas Kling 2022-08-18 15:23:56 +02:00
parent 45e6123de8
commit 27c1135d30
2 changed files with 8 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

26
Kernel/Memory/Region.cpp
View file

@ -237,14 +237,16 @@ bool Region::map_individual_page_impl(size_t page_index)
return true;
}
bool Region::do_remap_vmobject_page(size_t page_index, bool with_flush)
bool Region::remap_vmobject_page(size_t page_index, bool with_flush)
{
if (!m_page_directory)
return true; // not an error, region may have not yet mapped it
if (!translate_vmobject_page(page_index))
return true; // not an error, region doesn't map this page
SpinlockLocker page_lock(m_page_directory->get_lock());
SpinlockLocker lock(s_mm_lock);
SpinlockLocker mm_lock(s_mm_lock);
SpinlockLocker lock(m_vmobject->m_lock);
// NOTE: `page_index` is a VMObject page index, so first we convert it to a Region page index.
if (!translate_vmobject_page(page_index))
return false;
VERIFY(physical_page(page_index));
bool success = map_individual_page_impl(page_index);
if (with_flush)
@ -252,18 +254,6 @@ bool Region::do_remap_vmobject_page(size_t page_index, bool with_flush)
return success;
}
bool Region::remap_vmobject_page(size_t page_index, bool with_flush)
{
auto& vmobject = this->vmobject();
bool success = true;
SpinlockLocker lock(vmobject.m_lock);
vmobject.for_each_region([&](auto& region) {
if (!region.do_remap_vmobject_page(page_index, with_flush))
success = false;
});
return success;
}
void Region::unmap(ShouldFlushTLB should_flush_tlb)
{
if (!m_page_directory)