From b7dae4f90eca46220217b8a858afe5915f761a1b Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Tue, 10 Aug 2021 21:31:31 +0200
Subject: Kernel: Add CLOCK_MONOTONIC_COARSE to the kernel time page
This allows clock_gettime(CLOCK_MONOTONIC_COARSE) without syscalls.
Core::EventLoop takes advantage of this automatically. :^)
---
Kernel/API/TimePage.h | 2 +-
Kernel/Time/TimeManagement.cpp | 8 +++++---
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/Kernel/API/TimePage.h b/Kernel/API/TimePage.h
index e1492cd21f..76e6b44f8f 100644
--- a/Kernel/API/TimePage.h
+++ b/Kernel/API/TimePage.h
@@ -18,7 +18,7 @@ namespace Kernel {
inline bool time_page_supports(clockid_t clock_id)
{
- return clock_id == CLOCK_REALTIME_COARSE;
+ return clock_id == CLOCK_REALTIME_COARSE || clock_id == CLOCK_MONOTONIC_COARSE;
}
struct TimePage {
diff --git a/Kernel/Time/TimeManagement.cpp b/Kernel/Time/TimeManagement.cpp
index 9c43604965..6d9f6c6bf1 100644
--- a/Kernel/Time/TimeManagement.cpp
+++ b/Kernel/Time/TimeManagement.cpp
@@ -363,9 +363,9 @@ void TimeManagement::increment_time_since_boot_hpet()
// TODO: Apply m_remaining_epoch_time_adjustment
timespec_add(m_epoch_time, { (time_t)(delta_ns / 1000000000), (long)(delta_ns % 1000000000) }, m_epoch_time);
- update_time_page();
-
m_update1.store(update_iteration + 1, AK::MemoryOrder::memory_order_release);
+
+ update_time_page();
}
void TimeManagement::increment_time_since_boot()
@@ -396,8 +396,9 @@ void TimeManagement::increment_time_since_boot()
m_ticks_this_second = 0;
}
- update_time_page();
m_update1.store(update_iteration + 1, AK::MemoryOrder::memory_order_release);
+
+ update_time_page();
}
void TimeManagement::system_timer_tick(const RegisterState& regs)
@@ -432,6 +433,7 @@ void TimeManagement::update_time_page()
auto* page = time_page();
u32 update_iteration = AK::atomic_fetch_add(&page->update2, 1u, AK::MemoryOrder::memory_order_acquire);
page->clocks[CLOCK_REALTIME_COARSE] = m_epoch_time;
+ page->clocks[CLOCK_MONOTONIC_COARSE] = monotonic_time(TimePrecision::Coarse).to_timespec();
AK::atomic_store(&page->update1, update_iteration + 1u, AK::MemoryOrder::memory_order_release);
}
--
cgit debian/1.2.3+git2.25.1-1-2-gaceb0