git: DragonFly_RELEASE_4_6 kernel - Remove mplock from KTRACE paths
dillon at crater.dragonflybsd.org
Sun Oct 16 14:49:38 PDT 2016
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date: Tue Sep 27 14:39:03 2016 -0700
kernel - Remove mplock from KTRACE paths
* The mplock is no longer needed for KTRACE, ktrace writes are serialized
by the vnode lock and everything else is MPSAFE. Note that this change
means that even fast system calls may interleave in the ktrace output on
a multi-threaded program.
* Fix ktrace bug related to vkernels. The syscall2() code assumes that
no tokens are held on entry (since we are coming from usermode), but
a system call made from the vkernel may actually be nested inside
another syscall2(). The mplock KTRACE held caused this to assert in
the nested syscall2(). The removal of the mplock from the ktrace path
also fixes this bug.
* Minor comment adjustment in vm_vmspace.c.
Summary of changes:
sys/kern/sys_generic.c | 4 ----
sys/platform/pc64/x86_64/trap.c | 13 +++++--------
sys/vm/vm_vmspace.c | 8 +++++---
3 files changed, 10 insertions(+), 15 deletions(-)
DragonFly BSD source repository
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