Re: [Fwd: Re: Patch for inconsistent recording of block device statistics]

[Mark Seger <Mark.Seger@hp.com>]

yes, the patch worked.  The general discussion was that the byte counter 
gets incremented when requests are queued, not when they're acted upon 
as is the case with the count of I/Os.  As a result, the disk write 
numbers don't make any sense reporting impossibly high numbers (>100MB 
and as high as 450!) during some times and at other reporting zeros.  
The entire time, the I/O counts are happily showing what appear to be 
correct numbers.  Here's a snapshot taken during a portion of a 2GB file 
file to /tmp.

# DISK SUMMARY (/sec)
#         Reads  R-Merged  R-KBytes   Writes  W-Merged  W-KBytes
14:26:38      0         0         0        0         0         0
14:26:39      0         0         0       90      4391     18368
14:26:40      0         0         0      577     12603     52696
14:26:41      0         0         0      563    107835    446728
14:26:42      0         0         0      445         0         0
14:26:43      0         0         0      442         0         0
14:26:44      0         0         0      445         0         0
14:26:45      0         0         0      354         0         0
14:26:46      0         0         0      442         0         0
14:26:47      0         0         0      443         0         0
14:26:48      0         0         0      408         0         0
14:26:49      0         0         4      439       782      3280
14:26:50      1         0         0      462     12230     51160
14:26:51      0         0         0      574     88342    366116
14:26:52      0         0         0      477     32881    136604
14:26:53      0         0         0      443      9101     37656
14:26:54      0         0         0      442     11779     48736
14:26:55      0         0         0      373         0         0
14:26:56      0         0         0      415         0         0

-mark

Jens Axboe wrote:

> On Mon, Oct 24 2005, Mark Seger wrote:
>  
>
> > This patch was discussed back in march, and I still haven't seen it show 
> > up in the source pool.  I was wondering if it just feel through the 
> > cracks or if it was planned for a specific future release.  If the 
> > attached doesn't provide enough context for you to remember what this is 
> > all about, just let me know...
> >    
>
> Refresh my memory on where the discussion went after this email, I don't
> recall. Did the patch work for you?
>
>
>  

-
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