ladybird/Kernel/Syscalls/purge.cpp

72 lines
2.4 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/NonnullRefPtrVector.h>
#include <Kernel/Memory/AnonymousVMObject.h>
#include <Kernel/Memory/InodeVMObject.h>
#include <Kernel/Memory/MemoryManager.h>
#include <Kernel/Process.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$purge(int mode)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
REQUIRE_NO_PROMISES;
if (!is_superuser())
return EPERM;
size_t purged_page_count = 0;
if (mode & PURGE_ALL_VOLATILE) {
NonnullRefPtrVector<Memory::AnonymousVMObject> vmobjects;
{
KResult result(KSuccess);
MM.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 (!vmobjects.try_append(vmobject) && vmobjects.is_empty()) {
result = ENOMEM;
return IterationDecision::Break;
}
}
return IterationDecision::Continue;
});
if (result.is_error())
return result.error();
}
for (auto& vmobject : vmobjects) {
purged_page_count += vmobject.purge();
}
}
if (mode & PURGE_ALL_CLEAN_INODE) {
NonnullRefPtrVector<Memory::InodeVMObject> vmobjects;
{
KResult result(KSuccess);
MM.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 (!vmobjects.try_append(static_cast<Memory::InodeVMObject&>(vmobject)) && vmobjects.is_empty()) {
result = ENOMEM;
return IterationDecision::Break;
}
}
return IterationDecision::Continue;
});
if (result.is_error())
return result.error();
}
for (auto& vmobject : vmobjects) {
purged_page_count += vmobject.release_all_clean_pages();
}
}
return purged_page_count;
}
}