vmbufst subcommand

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The vmbufst subcommand displays VMM buf structures.

Format

vmbufst [bufaddr]

Parameters

Item Description
bufaddr Specifies the address of the buf structure to display. If the parameter is omitted, you are prompted to enter it.

The vmbufst subcommand is similar to the general filesystem buf subcommand. It displays a subset of the fields and automatically traverses any buf.av_forw chain.

Other

No aliases.

Examples

The following is an example of how to use the vmbufst subcommand:

KDB(7)> vmbufst
Enter address of the bufst:34DD79F0   //entered 34DD79F0> vmbufst 34DD79F0
flags.......: 000C8001
b_forw......: 00000000    b_back..... : 00000000
av_forw.....: 00000000    av_back.....: 00000000
iodone......: 020B0A0C    b_vp........: 00000000
b_dev.......: 000E0003    b_blkno.....: 01B82700
b_addr......: 00000000    b_bcount....: 00001000
b_error.....: 00          xmem is at  : 00504C78

KDB(7)> buf 34DD79F0                // contrast with the buf cmd
                  DEV    VNODE    BLKNO FLAGS

  0 34DD79F0 000E0003 00000000 01B82700 READ SPLIT MPSAFE INITIAL
forw     00000000 back     00000000 av_forw  00000000 av_back  00000000 
addr     00000000 blkno    01B82700 
vp       00000000 flags    000C8001 bcount   00001000 resid    00000000 
work     34E4B000 error    00000000 options  00000000 event    FFFFFFFF 
iodone:  020B0A0C
start.tv_sec       00015947 start.tv_nsec      00000000
xmemd.aspace_id    FFFFFFFC xmemd.prexflags    00000011
xmemd.orig_xmem    34DF0030 xmemd.rlist        34DF1030
orig.aspace_id     00000000 orig.subspace_id   008384CE
orig.subspace_id2  00000000 orig.uaddr         00000000

KDB(7)> 

Another difference between the two commands is that the vmbufst command
automatically traverses any av_forw list:
KDB(0)> buf @r5
                                  DEV    BLKNO FLAGS

  0 F10000AFD0024F00 8000000D00000001 00DE27F0 MPSAFE INITIAL
forw     0000000000000000 back     0000000000000000 
av_forw  F10000AFD002A780 av_back  0000000000000000 
addr     0000000000008000 blkno    0000000000DE27F0 
vp       0000000000000000 flags    00000000000C0000 
bcount   0000000000002000 resid    0000000000000000 
work     0000000000000001 error    00000000 
options  00000000 event    FFFFFFFFFFFFFFFF 
iodone:  034CD180
start.tv_sec       00000000401F4D2B start.tv_nsec      00000000 
xmemd.aspace_id    00000000         xmemd.num_sids     00000001 
xmemd.subspace_id  00010001914D9000 xmemd.vaddr        0000000000000000 
xmemd.prexflags    00000013         xmemd.xp@          F10000AFD0024FB0 
xmemd.xp.total     0000000000000020 xmemd.xp.used      0000000000000002 
xmemd.xp.s_vpn     0000000000000008 xmemd.xp.rpn       F100009E25733000 
KDB(0)> vmbufst @r5                       <also displays the buf at F10000AFD002A780>
flags.......: 00000000000C0000
b_forw......: 0000000000000000    b_back..... : 0000000000000000
av_forw.....: F10000AFD002A780    av_back.....: 0000000000000000
iodone......: 00000000034CD180    b_vp........: 0000000000000000
b_dev.......: 8000000D00000001    b_blkno.....: 0000000000DE27F0
b_addr......: 0000000000008000    b_bcount....: 0000000000002000
b_error.....: 00          xmem is at  : 0000000003016BB0

flags.......: 00000000000C0000
b_forw......: 0000000000000000    b_back..... : 0000000000000000
av_forw.....: 0000000000000000    av_back.....: 0000000000000000
iodone......: 00000000034CD180    b_vp........: 0000000000000000
b_dev.......: 8000000D00000001    b_blkno.....: 0000000000DE2800
b_addr......: 000000000000A000    b_bcount....: 0000000000002000
b_error.....: 00          xmem is at  : 0000000003016BB0

KDB(0)>