Re: [Crash-utility] [PATCH 0/8] makedumpfile: Add Snappy Compression Support
Hello HATAYAMA-san,
On Tue, 03 Jul 2012 12:07:27 +0900
HATAYAMA Daisuke <d.hatayama(a)jp.fujitsu.com> wrote:
This patch series add snappy compression support, applied on top of
v1.4.4. snappy is fast compressoin algorhythm like lzo, but it's more
optimized than lzo on x86 machines and some others.
A lot of benchmark is available on the web. Here I only point at my
benchmark I posted a few weeks ago,
- http://lists.infradead.org/pipermail/kexec/2012-June/006425.html
where snappy shows mostly as good performance as simple copying on
the worst case that input data increases its data size during
compression; this means we can use snappy with mostly NO risk.
How to get snappy libraries:
1) Use yum framework to get snappy and snappy-devel packages, or
2) Visit official website: http://code.google.com/p/snappy/,
download snappy-<version>.tar.gz and then build it.
How to build makedumpfile with snappy support:
Do make as follows:
$ make USESNAPPY=on
Thank you for your work.
I will merge your patches into the next version with small addition:
diff --git a/README b/README
index ae986d1..638b111 100644
--- a/README
+++ b/README
@@ -45,6 +45,9 @@
6.Build with lzo support:
# make USELZO=on ; make install
The user has to prepare lzo library.
+ 7.Build with snappy support:
+ # make USESNAPPY=on ; make install
+ The user has to prepare snappy library.
* SUPPORTED KERNELS
This makedumpfile supports the following kernels.
In addition, I did brief performance test with your patches:
- The source data is a vmcore saved on the disk, it might be sparse data.
- makedumpfile writes dumpfile to the same disk as the source data.
- execution time is average of 5 times.
| source | zlib | LZO | snappy
------------------------+---------------+-------------+-------------+-------------
size (byte) | 5,107,498,116 | 242,398,239 | 309,549,499 | 487,542,710
compression ratio(%) | --- | 4.75 | 6.06 | 9.55
execution time (sec) | --- | 143 | 49.6 | 51.2
It seems that LZO still has worth in the case that good compression ratio is expected,
as you said in your benchmark report.
Thanks
Atsushi Kumagai
---
HATAYAMA Daisuke (8):
Add manual description
Add help message
Add uncompression processing
Add compression processing
Notify snappy unsupporting when disabled
Add snappy build support
Add command-line processing for snappy
Add dump header for snappy
Makefile | 5 +++++
diskdump_mod.h | 2 ++
makedumpfile.8 | 9 +++++---
makedumpfile.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++------
makedumpfile.h | 3 +++
print_info.c | 16 ++++++++++-----
6 files changed, 80 insertions(+), 15 deletions(-)
--
Thanks.
HATAYAMA, Daisuke