From 3ba2449058b08bcf93a58143d1166b6b1e453859 Mon Sep 17 00:00:00 2001
From: Idan Horowitz <idan.horowitz@gmail.com>
Date: Fri, 6 Aug 2021 14:54:34 +0300
Subject: [PATCH] Kernel: Disable big process lock for sys$clock_nanosleep

This syscall doesn't touch any intra-process shared resources and only
accesses the time via the atomic TimeManagement::current_time so there's
no need to hold the big lock.
---
 Kernel/API/Syscall.h      | 2 +-
 Kernel/Syscalls/clock.cpp | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Kernel/API/Syscall.h b/Kernel/API/Syscall.h
index f9d6fd6401..73c1fbeeee 100644
--- a/Kernel/API/Syscall.h
+++ b/Kernel/API/Syscall.h
@@ -159,7 +159,7 @@ enum class NeedsBigProcessLock {
     S(setkeymap, NeedsBigProcessLock::Yes)                  \
     S(clock_gettime, NeedsBigProcessLock::No)               \
     S(clock_settime, NeedsBigProcessLock::Yes)              \
-    S(clock_nanosleep, NeedsBigProcessLock::Yes)            \
+    S(clock_nanosleep, NeedsBigProcessLock::No)             \
     S(join_thread, NeedsBigProcessLock::Yes)                \
     S(module_load, NeedsBigProcessLock::Yes)                \
     S(module_unload, NeedsBigProcessLock::Yes)              \
diff --git a/Kernel/Syscalls/clock.cpp b/Kernel/Syscalls/clock.cpp
index adb3e89f06..82e6779bcd 100644
--- a/Kernel/Syscalls/clock.cpp
+++ b/Kernel/Syscalls/clock.cpp
@@ -49,7 +49,7 @@ KResultOr<FlatPtr> Process::sys$clock_settime(clockid_t clock_id, Userspace<cons
 
 KResultOr<FlatPtr> Process::sys$clock_nanosleep(Userspace<const Syscall::SC_clock_nanosleep_params*> user_params)
 {
-    VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
+    VERIFY_NO_PROCESS_BIG_LOCK(this);
     REQUIRE_PROMISE(stdio);
 
     Syscall::SC_clock_nanosleep_params params;