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Re: [pcp] PCP Network Latency PMDA

To: David Smith <dsmith@xxxxxxxxxx>, "Frank Ch. Eigler" <fche@xxxxxxxxxx>
Subject: Re: [pcp] PCP Network Latency PMDA
From: William Cohen <wcohen@xxxxxxxxxx>
Date: Wed, 20 Aug 2014 16:27:06 -0400
Cc: pcp@xxxxxxxxxxx
Delivered-to: pcp@xxxxxxxxxxx
In-reply-to: <53EBB063.9040103@xxxxxxxxxx>
References: <53A34A47.3060008@xxxxxxxxxx> <y0mk38caa4t.fsf@xxxxxxxx> <53A353C8.8030704@xxxxxxxxxx> <53A35C00.1070703@xxxxxxxxxx> <53EA6650.6040500@xxxxxxxxxx> <53EB7A09.7070503@xxxxxxxxxx> <53EB9262.104@xxxxxxxxxx> <53EBB063.9040103@xxxxxxxxxx>
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0
On 08/13/2014 02:37 PM, William Cohen wrote:
 
> The script doesn't seem to work with multiple instances, but it does work for 
> a single network device.  In one window started the systemtap script:

David made some fixes in the runtime library and things are now working for 
multiple instances.  In one window on fc20 machine:


$ ../install/bin/stap  ../../net_xmit_mmv.stp em1 loem1 0
lo 1
argv[1] = em1, inst[em1] = 0
argv[2] = lo, inst[lo] = 1


In another window can get information out with mmvdump:

$ ./mmvdump /proc/systemtap/*/mmv 
MMV file   = /proc/systemtap/stap_379c8b3dbc82aa6899b31e84adf6d6fa_15475/mmv
Version    = 1
Generated  = 976056
TOC count  = 5
Cluster    = 43
Process    = 0
Flags      = 0x0

TOC[0]: offset 40, indoms offset 1704 (1 entries)
  [1/1704] 2 instances, starting at offset 1736
       shorttext=xmit device
       helptext=list of network transmit devices

TOC[1]: offset 56, instances offset 1736 (2 entries)
  [1/1736] instance = [0 or "em1"]
  [1/1816] instance = [1 or "lo"]

TOC[2]: toc offset 72, metrics offset 1896 (2 entries)
  [1/1896] xmit_count
       type=64-bit int (0x2), sem=counter (0x1), pad=0x0
       units=count
       indom=1
       shorttext=xmit count metric
       helptext=number of packets for xmit device
  [2/2000] xmit_latency
       type=64-bit int (0x2), sem=counter (0x1), pad=0x0
       units=nanosec
       indom=1
       shorttext=xmit latency metric
       helptext=sum of latency for xmit device

TOC[3]: offset 88, values offset 2264 (4 entries)
  [1/2264] xmit_count[0 or "em1"] = 31
  [1/2296] xmit_count[1 or "lo"] = 8589
  [2/2328] xmit_latency[0 or "em1"] = 160804
  [2/2360] xmit_latency[1 or "lo"] = 2947849

TOC[4]: offset 104, string offset 168 (6 entries)
  [1/168] xmit device
  [2/424] list of network transmit devices
  [3/680] xmit count metric
  [4/936] number of packets for xmit device
  [5/1192] xmit latency metric
  [6/1448] sum of latency for xmit device

-Will

Attachment: net_xmit_mmv.stp
Description: Text document

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