Mark mmap(2), munmap(2) and mprotect(2) as NOLOCK.

Accesses to data structures used by these syscalls are serialized by the
VM map lock with the exception of file mappings which are still protected
by the KERNEL_LOCK().

Unlocking this set of syscalls improves most of userland workloads.

Tested by many including robert@ (since 2 years), mlarkin@, kn@, sdk@,
jca@, aoyama@, naddy@, Scott Bennett and others. Thanks to all!

Joint work with kn@.

ok robert@, aja@, kettenis@, kn@, deraadt@, beck@

diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index 5b5cbbe..59f4a97 100644 (file)
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -1,4 +1,4 @@
-;      $OpenBSD: syscalls.master,v 1.234 2022/10/25 16:10:31 kettenis Exp $
+;      $OpenBSD: syscalls.master,v 1.235 2022/11/08 11:05:57 mpi Exp $
 ;      $NetBSD: syscalls.master,v 1.32 1996/04/23 10:24:21 mycroft Exp $
 
 ;      @(#)syscalls.master     8.2 (Berkeley) 1/13/94
@@ -126,7 +126,7 @@
                            struct sigaction *osa); }
 47     STD NOLOCK      { gid_t sys_getgid(void); }
 48     STD NOLOCK      { int sys_sigprocmask(int how, sigset_t mask); }
-49     STD             { void *sys_mmap(void *addr, size_t len, int prot, \
+49     STD NOLOCK      { void *sys_mmap(void *addr, size_t len, int prot, \
                            int flags, int fd, off_t pos); }
 50     STD             { int sys_setlogin(const char *namebuf); }
 #ifdef ACCOUNTING
@@ -171,8 +171,8 @@
                            const struct kevent *changelist, int nchanges, \
                            struct kevent *eventlist, int nevents, \
                            const struct timespec *timeout); }
-73     STD             { int sys_munmap(void *addr, size_t len); }
-74     STD             { int sys_mprotect(void *addr, size_t len, \
+73     STD NOLOCK      { int sys_munmap(void *addr, size_t len); }
+74     STD NOLOCK      { int sys_mprotect(void *addr, size_t len, \
                            int prot); }
 75     STD             { int sys_madvise(void *addr, size_t len, \
                            int behav); }