ladybird/Kernel/Syscalls/purge.cpp

72 lines
2.6 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Memory/AnonymousVMObject.h>
#include <Kernel/Memory/InodeVMObject.h>
#include <Kernel/Memory/MemoryManager.h>
#include <Kernel/Tasks/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$purge(int mode)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_no_promises());
auto credentials = this->credentials();
if (!credentials->is_superuser())
return EPERM;
size_t purged_page_count = 0;
if (mode & PURGE_ALL_VOLATILE) {
Vector<NonnullLockRefPtr<Memory::AnonymousVMObject>> vmobjects;
{
ErrorOr<void> result;
Memory::MemoryManager::for_each_vmobject([&](auto& vmobject) {
if (vmobject.is_anonymous()) {
// In the event that the append fails, only attempt to continue
// the purge if we have already appended something successfully.
if (auto append_result = vmobjects.try_append(static_cast<Memory::AnonymousVMObject&>(vmobject)); append_result.is_error() && vmobjects.is_empty()) {
result = append_result.release_error();
return IterationDecision::Break;
}
}
return IterationDecision::Continue;
});
if (result.is_error())
return result.release_error();
}
for (auto& vmobject : vmobjects) {
purged_page_count += vmobject->purge();
}
}
if (mode & PURGE_ALL_CLEAN_INODE) {
Vector<NonnullLockRefPtr<Memory::InodeVMObject>> vmobjects;
{
ErrorOr<void> result;
Memory::MemoryManager::for_each_vmobject([&](auto& vmobject) {
if (vmobject.is_inode()) {
// In the event that the append fails, only attempt to continue
// the purge if we have already appended something successfully.
if (auto append_result = vmobjects.try_append(static_cast<Memory::InodeVMObject&>(vmobject)); append_result.is_error() && vmobjects.is_empty()) {
result = append_result.release_error();
return IterationDecision::Break;
}
}
return IterationDecision::Continue;
});
if (result.is_error())
return result.release_error();
}
for (auto& vmobject : vmobjects) {
purged_page_count += vmobject->release_all_clean_pages();
}
}
return purged_page_count;
}
}