From: Cliff Wickman <cpw@sgi.com>
To: kexec@lists.infradead.org
Cc: d.hatayama@jp.fujitsu.com, kumagai-atsushi@mxc.nes.nec.co.jp
Subject: makedumpfile 1.5.4, 734G kdump tests
Date: Tue, 9 Jul 2013 11:24:03 -0500 [thread overview]
Message-ID: <20130709162403.GA25441@sgi.com> (raw)
I have run some tests with the latest makedumpfile and kexec and the
results (below) look very good to me.
This particular test machine has a megaraid root, which had been a problem
with previous kexec-tools (I did have to allocate a lot of low memory).
My 3.10 kernel does have Hatayama's vmcore mmap patches.
My only remaining concern for makedumpfile is the filtering of huge pages.
I believe that patch is in progress; but I don't see it in 1.5.4.
-Cliff
UV2000 memory: 734G
makedumpfile: makedumpfile-1.5.4
kexec: git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
booted with crashkernel=1G,high crashkernel=192M,low
non-cyclic mode
write to option init&scan sec. copy sec. dump size
------------- ----------------- ---- --------- ---------
megaraid disk no compression 19 91 11.7G
megaraid disk zlib compression 20 209 1.4G
megaraid disk snappy compression 20 46 2.4G
megaraid disk snappy compression no mmap 30 72 2.4G
/dev/null no compression 19 28 -
/dev/null zlib compression 19 206 -
/dev/null snappy compression 19 41 -
Notes and observations
- Snappy compression is a big win over zlib compression; over 4 times faster
with a cost of relatively little disk space.
- The vmcore mmap kernel patch cuts off about 1/3 of both page scan time and
data copy time.
I hope those patches reach Linus' tree shortly, as you expect.
- Data copy time is dominated by compression time; writing compressed data
to /dev/null uses almost the same time as writing to disk.
I hope your efforts to multi-thread the crash kernel go forward.
--
Cliff Wickman
SGI
cpw@sgi.com
(651) 683-3824
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next reply other threads:[~2013-07-09 16:24 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-09 16:24 Cliff Wickman [this message]
[not found] ` <CAJGZr0JPrBB3cVyVdwJdd6cEUfnXNMuRijb9EOoSy+XmRupv7A@mail.gmail.com>
2013-07-10 9:07 ` makedumpfile 1.5.4, 734G kdump tests HATAYAMA Daisuke
[not found] ` <CAJGZr0L7GBqJHaPzgpFxhpF_jmAZfDJYU_=MFxATxnLk13ni4g@mail.gmail.com>
2013-07-10 18:27 ` Cliff Wickman
2013-07-11 13:06 ` Vivek Goyal
2013-07-12 16:14 ` Cliff Wickman
2013-07-12 16:42 ` Vivek Goyal
2013-07-16 9:22 ` HATAYAMA Daisuke
2013-07-16 14:15 ` Vivek Goyal
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