From 3f1ea1975a58479fa08ead002d32a9076f273e23 Mon Sep 17 00:00:00 2001 From: peter Date: Mon, 5 May 1997 05:58:33 +0000 Subject: [PATCH] Mention the removal of UPAGES, the return-to-userspace fork(), and the fast complete implementation of vfork(). --- release/sysinstall/help/relnotes.hlp | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/release/sysinstall/help/relnotes.hlp b/release/sysinstall/help/relnotes.hlp index e2911c62a544..2ee4564e1ae8 100644 --- a/release/sysinstall/help/relnotes.hlp +++ b/release/sysinstall/help/relnotes.hlp @@ -34,13 +34,28 @@ previous hackery involving struct in_ifaddr and arpcom. Get rid of the abominable multi_kludge. The new if_media selection method for ethernet drivers has been brought -in, obtained from Jason Thorpe's NetBSD implementation. +in, obtained from Jason Thorpe's implementation for NetBSD. Multi-session ISO-9660 CD-ROMs are now fully supported. By default, the last session will be mounted (including for root mounts). For non-root mounts, mount_cd9660(8) can take an argument to mount a particular session instead of the default one. +The UPAGES are gone from the per-process address space which allows +complete address space and page table sharing by reference count. + +Newly forked child processes return directly to user mode rather than +return up through the fork() syscall tree. This eliminates the kernel +stack copy at fork time and simplifies certain other internal operations. +It is also needed to support the removal of the UPAGES. (The idea for +this originally came from NetBSD, but we did it for different reasons.) + +vfork() is now fully functional by taking advantage of the new sharing +semantics and a significant speedup has been measured. This can be +disabled via the kern.fast_vfork sysctl variable in case of problems. +Statically linked binaries from older releases and other BSD platforms +are a problem since there was a bug in the 4.4BSD (net2, Lite and Lite2) +popen() implementation. 2. Supported Configurations ---------------------------