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Kernel: Remove the "kernel info page" used for fast gettimeofday()

We stopped using gettimeofday() in Core::EventLoop a while back,
in favor of clock_gettime() for monotonic time.

Maintaining an optimization for a syscall we're not using doesn't make
a lot of sense, so let's go back to the old-style sys$gettimeofday().
This commit is contained in:
Andreas Kling 2020-05-16 11:18:04 +02:00
parent 4e27c58be7
commit 3a92d0828d
6 changed files with 7 additions and 46 deletions

View file

@ -95,7 +95,6 @@
namespace Kernel {
static void create_signal_trampolines();
static void create_kernel_info_page();
Process* Process::current;
@ -103,8 +102,6 @@ static pid_t next_pid;
InlineLinkedList<Process>* g_processes;
static String* s_hostname;
static Lock* s_hostname_lock;
static VirtualAddress s_info_page_address_for_userspace;
static VirtualAddress s_info_page_address_for_kernel;
VirtualAddress g_return_to_ring3_from_signal_trampoline;
HashMap<String, OwnPtr<Module>>* g_modules;
@ -124,14 +121,6 @@ void Process::initialize()
s_hostname_lock = new Lock;
create_signal_trampolines();
create_kernel_info_page();
}
void Process::update_info_page_timestamp(const timeval& tv)
{
auto* info_page = (KernelInfoPage*)s_info_page_address_for_kernel.as_ptr();
info_page->serial++;
const_cast<timeval&>(info_page->now) = tv;
}
Vector<pid_t> Process::all_pids()
@ -1500,15 +1489,6 @@ void create_signal_trampolines()
trampoline_region->remap();
}
void create_kernel_info_page()
{
auto* info_page_region_for_userspace = MM.allocate_user_accessible_kernel_region(PAGE_SIZE, "Kernel info page", Region::Access::Read).leak_ptr();
auto* info_page_region_for_kernel = MM.allocate_kernel_region_with_vmobject(info_page_region_for_userspace->vmobject(), PAGE_SIZE, "Kernel info page", Region::Access::Read | Region::Access::Write).leak_ptr();
s_info_page_address_for_userspace = info_page_region_for_userspace->vaddr();
s_info_page_address_for_kernel = info_page_region_for_kernel->vaddr();
memset(s_info_page_address_for_kernel.as_ptr(), 0, PAGE_SIZE);
}
int Process::sys$sigreturn(RegisterState& registers)
{
REQUIRE_PROMISE(stdio);
@ -2330,7 +2310,7 @@ int Process::sys$sleep(unsigned seconds)
timeval kgettimeofday()
{
return const_cast<const timeval&>(((KernelInfoPage*)s_info_page_address_for_kernel.as_ptr())->now);
return g_timeofday;
}
void compute_relative_timeout_from_absolute(const timeval& absolute_time, timeval& relative_time)
@ -4639,12 +4619,6 @@ int Process::sys$profiling_disable(pid_t pid)
return 0;
}
void* Process::sys$get_kernel_info_page()
{
REQUIRE_PROMISE(stdio);
return s_info_page_address_for_userspace.as_ptr();
}
Thread& Process::any_thread()
{
Thread* found_thread = nullptr;