svn commit: r288453 - in stable/10: lib/libutil sys/sys sys/vm usr.bin/vmstat

[John Baldwin]

On Thursday, October 01, 2015 05:09:21 PM John Baldwin wrote:
> Author: jhb
> Date: Thu Oct  1 17:09:20 2015
> New Revision: 288453
> URL: https://svnweb.freebsd.org/changeset/base/288453
> 
> Log:
>   MFC 283624,283630:
>   Export a list of VM objects in the system via a sysctl.  The list can be
>   examined via 'vmstat -o'.  It can be used to determine which files are
>   using physical pages of memory and how much each is using.

Note that userland sysctls in stable/10 are single-threaded.  Thus, other
programs that use sysctls will hang while this new sysctl runs.  Resolving
the pathnames of mapped files can take a while, especially if any NFS files
are mapped (on the order of seconds).  Programs like top(1), ps(1), fstat(1),
vmstat(1), etc. all use sysctls to fetch information, so they will all hang
while 'vmstat -o' runs.  This does not mean the entire machine has locked up,
but it can feel like it.  User beware, etc.

-- 
John Baldwin