Add memstat_kvm_uma(), an implementation of a libmemstat(3) query routine

that knows how to extract UMA(9) allocator statistics from a core dump or
live memory image using kvm(3).  The caller is expected to provide the
necessary kvm_t handle, which is then used by libmemstat(3).

With these changes, it is trivially straight forward to re-introduce
vmstat -z support on core dumps, which was lost when UMA was introduced.

In the short term, this requires including vm/ include files that are not
intended for extra-kernel use, requiring in turn some ugliness.

1 files changed, 7 insertions, 2 deletions

diff --git a/lib/libmemstat/libmemstat.3 b/lib/libmemstat/libmemstat.3
index 0bc341035c32..a851e5e40cf2 100644
--- a/lib/libmemstat/libmemstat.3
+++ b/lib/libmemstat/libmemstat.3
@@ -53,6 +53,8 @@
 .Fn memstat_mtl_geterror "struct memory_type_list *list"
 .Ss Allocator Query Functions
 .Ft int
+.Fn memstat_kvm_uma "struct memory_type_list *list" "void *kvm_handle"
+.Ft int
 .Fn memstat_sysctl_all "struct memory_type_list *list" "int flags"
 .Ft int
 .Fn memstat_sysctl_malloc "struct memory_type_list *list" "int flags"
@@ -145,6 +147,7 @@ and freed on completion using
 .Fn memstat_mtl_free .
 Lists of memory types are populated via calls that query the kernel for
 statistics information; currently:
+.Fn memstat_kvm_uma ,
 .Fn memstat_sysctl_all ,
 .Fn memstat_sysctl_uma ,
 and
@@ -443,8 +446,10 @@ monitoring library, along with the library, were written by
 .An Robert Watson Aq rwatson@FreeBSD.org
 .Sh BUGS
 .Nm
-cannot yet extract statistics from kernel core dumps, although this should be
-straight forward to implement.
+cannot yet extract
+.Xr malloc 9
+statistics from kernel core dumps, although this should be straight forward
+to implement.
 .Pp
 Once a memory type is present on a memory type list, it will not be removed
 even if the kernel no longer presents information on the type via its