[libvirt] [PATCH v3] virsh: Add more human-friendly output of domblkstat command

[Peter Krempa]

On 09/07/2011 01:45 PM, Osier Yang wrote:
> 于 2011年09月06日 21:20, Peter Krempa 写道:
>> diff --git a/tools/virsh.c b/tools/virsh.c
>> index 629233f..458252b 100644
>> --- a/tools/virsh.c
>> +++ b/tools/virsh.c
>> @@ -1054,16 +1054,46 @@ cleanup:
>>    */
>>   static const vshCmdInfo info_domblkstat[] = {
>>       {"help", N_("get device block stats for a domain")},
>> -    {"desc", N_("Get device block stats for a running domain.")},
>> +    {"desc", N_("Get device block stats for a running domain.\n\n"
>> +                "    Explanation of fields:\n"
>> +                "      rd_req            - count of read operations 
>> (old format)\n"
>> +                "      rd_operations     - count of read operations 
>> (new format)\n"
>> +                "      rd_bytes          - count of read bytes\n"
>> +                "      rd_total_times    - total time read 
>> operations took\n"
>
> Should also document the units IMHO, it's nano-seconds.
I agree, that documenting also the unit is important. I'm afraid that 
the unit is hypervisor specific
(by now, the code is implemented only for QEmu) and we would create a 
precedent so that other
hypervisors using other values will have to convert it before. I think 
we should chose this unit wisely.

On the other hand, I think that nano-seconds are okay.
>
>> +                "      wr_req            - count of write operations 
>> (old format)\n"
>> +                "      wr_operations     - count of write operations 
>> (new format)\n"
>> +                "      wr_bytes          - count of written bytes\n"
>
> Missed docs for wr_total_times.
Will add it in v4
>
>> +                "      flush_operations  - count of flush operations\n"
>> +                "      flush_total_times - total time flush 
>> operations took\n"
>
> likewise
>
>> +                "      errs              - error count")},
>>       {NULL,NULL}
>>   };
>
> Think it would be better if converting "rd_operations", "wr_operations",
> and "flush_operations" to the old names. They have the same meaning,
> and we used "rd_req", "wr_req" in virsh for a long time. After 
> conversion,
> we can have less and not duplicate documention.
I am aware, that the meanings of the two fields are the same. I was 
surprised
to see new naming of this fields. If the new API has to stick with these 
new names,
I'll have to convert them, but I don't really like approach.
>
>>   static const vshCmdOptDef opts_domblkstat[] = {
>>       {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or 
>> uuid")},
>>       {"device", VSH_OT_DATA, VSH_OFLAG_REQ, N_("block device")},
>> +    {"human",  VSH_OT_BOOL, 0, N_("print a more human readable 
>> output")},
>>       {NULL, 0, 0, NULL}
>>   };
>>
>> +struct _domblkstat_human_readable {
>> +    const char *field;
>> +    const char *human;
>> +};
>> +
>> +static const struct _domblkstat_human_readable 
>> domblkstat_translate[] = {
>> +    { VIR_DOMAIN_BLOCK_STATS_READ_BYTES,        N_("number of read 
>> bytes:      ") }, /* 0 */
>> +    { VIR_DOMAIN_BLOCK_STATS_READ_REQ,          N_("number of read 
>> operations: ") }, /* 1 */
>> +    { VIR_DOMAIN_BLOCK_STATS_READ_TOTAL_TIMES,  N_("total duration 
>> of reads:   ") }, /* 2 */
>> +    { VIR_DOMAIN_BLOCK_STATS_WRITE_BYTES,       N_("number of bytes 
>> written:   ") }, /* 3 */
>> +    { VIR_DOMAIN_BLOCK_STATS_WRITE_REQ,         N_("number of write 
>> operations:") }, /* 4 */
>> +    { VIR_DOMAIN_BLOCK_STATS_WRITE_TOTAL_TIMES, N_("total duration 
>> of writes:  ") }, /* 5 */
>> +    { VIR_DOMAIN_BLOCK_STATS_FLUSH_REQ,         N_("number of flush 
>> operations:") }, /* 6 */
>> +    { VIR_DOMAIN_BLOCK_STATS_FLUSH_TOTAL_TIMES, N_("total duration 
>> of flushes: ") }, /* 7 */
>
> Not sure if we should keep the same docs for these fields defined in 
> struct
> info_domblkstat and virsh.pod? it looks a bit long though. :-)
Yes this information is tripple-redundant :/ but I don't really see 
other options. Maybe just drop it from
help command as there is the --human option, or drop the human option.
>
>> +    { VIR_DOMAIN_BLOCK_STATS_ERRS,              N_("error 
>> count:               ") }, /* 8 */
>> +    { NULL, NULL }
>> +};

>> diff --git a/tools/virsh.pod b/tools/virsh.pod
>> index d826997..c8d88c9 100644
>> --- a/tools/virsh.pod
>> +++ b/tools/virsh.pod
>> @@ -501,13 +501,27 @@ be lost once the guest stops running, but the 
>> snapshot contents still
>>   exist, and a new domain with the same name and UUID can restore the
>>   snapshot metadata with B<snapshot-create>.
>>
>> -=item B<domblkstat>  I<domain>  I<block-device>
>> +=item B<domblkstat>  I<domain>  I<block-device>  [I<--human>]
>>
>>   Get device block stats for a running domain.  A I<block-device>  
>> corresponds
>>   to a unique target name (<target dev='name'/>) or source file (<source
>>   file='name'/>) for one of the disk devices attached to I<domain>  (see
>>   also B<domblklist>  for listing these names).
>>
>> +Use I<--human>  for a more human readable output.
>> +
>> +B<Explanation of fields:>
>> +  rd_req            - count of read operations (old format)
>> +  rd_operations     - count of read operations (new format)
>> +  rd_bytes          - count of read bytes
>> +  rd_total_times    - total time read operations took
>
> Units
Fix in v4.
>
>> +  wr_req            - count of write operations (old format)
>> +  wr_operations     - count of write operations (new format)
>> +  wr_bytes          - count of written bytes
>
> Missed wr_total_times
Fix in v4.
>
>> +  flush_operations  - count of flush operations
>> +  flush_total_times - total time flush operations took
>
> Units.
Fix in v4.
>
>> +  errs              - error count
>> +
>>   =item B<domifstat>  I<domain>  I<interface-device>
>>
>>   Get network interface stats for a running domain.
>
> Others look good to me.
>
> Regards
> Osier
Thanks for finding the small glitches.

Peter