Re: [Crash-utility] [RFC] makedumpfile, crash: LZO compression support
> Hello Hatayama-san,
>
> Thank you for your work.
>
>> Performance Comparison:
>>
>> Sample Data
>>
>> Ideally, I must have measured the performance for many enough
>> vmcores generated from machines that was actually running, but now
>> I don't have enough sample vmcores, I couldn't do so. So this
>> comparison doesn't answer question on I/O time improvement. This
>> is TODO for now.
>
> I'll measure the performance for actual vmcores by makedumpfile.
> Please wait for a while.
I measured the performance of makedumpfile for some vmcores.
Please see below.
Sample Data
To simulate a working server, I captured VMCOREs while almost all pages
were alloceted and filled with random data. (See attached file
"fill_random.c")
I captured the VMCOREs of 5GB, 7.5GB and 10GB in the same condition.
How to measure
I measured the total execution time and the size of output file.
$ time makedumpfile --message-level 16 [-c|-l| ] vmcore dumpfile
Result
See attached file "result.txt".
This time, lzo's compression was the quickest, and lzo's compression ratio is
almost the same(only a bit worse) as zlib's.
It seems good, and I will merge the patch set into the makedumpfile.
What is your opinion, Dave?
Thanks.
KUMAGAI, Atsushi
That's very helpful. Thanks in advance.
But of course I'm also still looking for alternative way.
Thanks.
HATAYAMA, Daisuke
Attachments:
- fill_random.c (text/x-csrc — 826 bytes)
- compressed_page_report.patch (application/octet-stream — 2.3 KB)
- result.txt (text/plain — 1.1 KB)