| commit | 5ee06c6c187e324caf18efa964c1afedd2206031 | |
| author | Matthew Dillon <dillon@apollo.backplane.com> | |
| Sun, 29 Jan 2017 04:02:03 +0000 (28 20:02 -0800) | ||
| committer | Matthew Dillon <dillon@apollo.backplane.com> | |
| Sun, 29 Jan 2017 05:42:31 +0000 (28 21:42 -0800) | ||
| tree | 42bd37353078c3fd3d76e05fcb419e27ed046188 | treesnapshot (tar.gz zip) |
| parent | 07540d375a7f9dfdadc9976982dd8d0a1fd6794e | commitdiff |
kernel - Fix races created by a comedy of circumstances
* Fix several loop iteration races in the pmap code revealed by a chain
of events. Initially the commit to relax locking of vm_map for
MADV_INVAL operations (used by the vkernel) worked just fine. The
idea being that the pmap code was fine-grained locked and so a wider
encompassing lock should not have been needed.
However, a later commit to reduce the size of the zalloc pcpu caches
caused more cycling of pv_entry structures across cpus which revealed
a number of SMP races in the pmap code.
* A number of these races were fixed in recent commits and this commit
fixes a few more, primarily in the vm_page_t pv_entry loop iterators.
* Fix several loop iteration races in the pmap code revealed by a chain
of events. Initially the commit to relax locking of vm_map for
MADV_INVAL operations (used by the vkernel) worked just fine. The
idea being that the pmap code was fine-grained locked and so a wider
encompassing lock should not have been needed.
However, a later commit to reduce the size of the zalloc pcpu caches
caused more cycling of pv_entry structures across cpus which revealed
a number of SMP races in the pmap code.
* A number of these races were fixed in recent commits and this commit
fixes a few more, primarily in the vm_page_t pv_entry loop iterators.
| sys/platform/pc64/x86_64/pmap.c | diffblobblamehistory | |
| sys/platform/vkernel64/platform/pmap.c | diffblobblamehistory |