DragonFly commits List (threaded) for 2009-12
git: kernel - pmap (mainly i386) - fix TLB race and other issues
Author: Matthew Dillon <firstname.lastname@example.org>
Date: Wed Dec 30 09:10:18 2009 -0800
kernel - pmap (mainly i386) - fix TLB race and other issues
* Temporary fix for a TLB race. Due to threading a process pmap
may be mapped to multiple cpus. The APTmap is built into the
per-process pmap and used for temporary page table mappings.
The i386 pmap code was only invalidating the TLB if the APTmap
had to be updated, but did not consider the possibility that
it would be accessed from a different cpu than the one it was
originally installed in.
Add a simple global cpumask to avoid the degenerate case.
This is a bit of overkill. A followup commit will move
APTmap into the globaldata structure as a more permanent
The vkernel and x86_64 pmap code do not have this issue. The
vkernel pmap code already uses a per-globaldata pmap and
the x86_64 pmap code uses the direct phys map.
* Add a ton of debugging code articulated with PMAP_DEBUG in
case I ever have to do this again. Default disabled.
* Fix a few minor issues in the pmap code.
(1) The pv in pmap_remove_entry() is not optional.
(2) Add a few minor missing pmap->pm_generation increments.
(3) Add a missing critical section.
(4) Remove an unused #define.
* Zalloc code. No specific bugs but make sure the ZONE_INTERRUPT
code acquires the MP lock when/if it needs to expand the mapping.
Reported-by: YONETANI Tomokazu <email@example.com>
Summary of changes:
sys/platform/pc32/i386/pmap.c | 180 +++++++++++++++++++++++++++++-----
sys/platform/pc32/include/pmap.h | 19 ++++-
sys/platform/pc64/x86_64/pmap.c | 38 +++++---
sys/platform/vkernel/platform/pmap.c | 30 ++++--
sys/vm/vm_zone.c | 16 +++-
5 files changed, 228 insertions(+), 55 deletions(-)
DragonFly BSD source repository