[PATCH RFC 00/11] makedumpfile: parallel processing

Chao Fan cfan at redhat.com
Thu Dec 24 01:04:36 PST 2015



----- Original Message -----
> From: "Atsushi Kumagai" <ats-kumagai at wm.jp.nec.com>
> To: "HATAYAMA Daisuke (d.hatayama at jp.fujitsu.com)" <d.hatayama at jp.fujitsu.com>, "Chao Fan" <cfan at redhat.com>
> Cc: zhouwj-fnst at cn.fujitsu.com, kexec at lists.infradead.org
> Sent: Thursday, December 24, 2015 4:20:42 PM
> Subject: RE: [PATCH RFC 00/11] makedumpfile: parallel processing
> 
> >> >> >> >> Could you provide the information of your cpu ?
> >> >> >> >> I will do some further investigation later.
> >> >> >> >>
> >> >> >> >
> >> >> >> > OK, of course, here is the information of cpu:
> >> >> >> >
> >> >> >> > # lscpu
> >> >> >> > Architecture:          x86_64
> >> >> >> > CPU op-mode(s):        32-bit, 64-bit
> >> >> >> > Byte Order:            Little Endian
> >> >> >> > CPU(s):                48
> >> >> >> > On-line CPU(s) list:   0-47
> >> >> >> > Thread(s) per core:    1
> >> >> >> > Core(s) per socket:    6
> >> >> >> > Socket(s):             8
> >> >> >> > NUMA node(s):          8
> >> >> >> > Vendor ID:             AuthenticAMD
> >> >> >> > CPU family:            16
> >> >> >> > Model:                 8
> >> >> >> > Model name:            Six-Core AMD Opteron(tm) Processor 8439 SE
> >> >> >> > Stepping:              0
> >> >> >> > CPU MHz:               2793.040
> >> >> >> > BogoMIPS:              5586.22
> >> >> >> > Virtualization:        AMD-V
> >> >> >> > L1d cache:             64K
> >> >> >> > L1i cache:             64K
> >> >> >> > L2 cache:              512K
> >> >> >> > L3 cache:              5118K
> >> >> >> > NUMA node0 CPU(s):     0,8,16,24,32,40
> >> >> >> > NUMA node1 CPU(s):     1,9,17,25,33,41
> >> >> >> > NUMA node2 CPU(s):     2,10,18,26,34,42
> >> >> >> > NUMA node3 CPU(s):     3,11,19,27,35,43
> >> >> >> > NUMA node4 CPU(s):     4,12,20,28,36,44
> >> >> >> > NUMA node5 CPU(s):     5,13,21,29,37,45
> >> >> >> > NUMA node6 CPU(s):     6,14,22,30,38,46
> >> >> >> > NUMA node7 CPU(s):     7,15,23,31,39,47
> >> >> >>
> >> >> >> This CPU assignment on NUMA nodes looks interesting. Is it possible
> >> >> >> that this affects performance of makedumpfile? This is just a guess.
> >> >> >>
> >> >> >> Could you check whether the performance gets imporoved if you run
> >> >> >> each
> >> >> >> thread on the same NUMA node? For example:
> >> >> >>
> >> >> >>   # taskset -c 0,8,16,24 makedumpfile --num-threads 4 -c -d 0 vmcore
> >> >> >>   vmcore-cd0
> >> >> >>
> >> >> > Hi HATAYAMA,
> >> >> >
> >> >> > I think your guess is right, but maybe your command has a little
> >> >> > problem.
> >> >> >
> >> >> > From my test, the NUMA did affect the performance, but not too much.
> >> >> > The average time of cpus in the same NUMA node:
> >> >> > # taskset -c 0,8,16,24,32 makedumpfile --num-threads 4 -c -d 0 vmcore
> >> >> > vmcore-cd0
> >> >> > is 314s
> >> >> > The average time of cpus in different NUMA node:
> >> >> > # taskset -c 2,3,5,6,7 makedumpfile --num-threads 4 -c -d 0 vmcore
> >> >> > vmcore-cd0
> >> >> > is 354s
> >> >> >
> >> >>
> >> >> Hmm, according to some previous discussion, what we should see here is
> >> >> whether it affects performance of makedumpfile with --num-threads 1
> >> >> and -d 31. So you should need to compare:
> >> >>
> >> >>     # taskset 0,8 makedumpfile --num-threads 1 -c -d 31 vmcore
> >> >>     vmcore-d31
> >> >>
> >> >> with:
> >> >>
> >> >>     # taskset 0 makedumpfile -c -d 0 vmcore vmcore-d31
> >>
> >> I removed -c option wrongly. What I wanted to write is:
> >>
> >>     # taskset -c 0,8 makedumpfile --num-threads 1 -d 31 vmcore vmcore-d31
> >>
> >> and:
> >>
> >>     # taskset -c 0 makedumpfile -d 31 vmcore vmcore-d31
> >>
> >> just in case...
> 
> Why did you remove -c option from makedumpfile ?
> We are discussing the performance with compression.
> I think the below is correct:
> 
>        # taskset -c 0,8 makedumpfile --num-threads 1 [-c|-l|-p] -d 31 vmcore
>        vmcore-d31
> 
> and:
> 
>        # taskset -c 0 makedumpfile [-c|-l|-p] -d 31 vmcore vmcore-d31
> 

Hi Atsushi Kumagai,

   "taskset -c 0,8 makedumpfile --num-threads 1"   "taskset -c 0 makedumpfile"
-c              52s                                         61s
-l              33s                                         17s
-p              33s                                         18s

Thanks,
Chao Fan

> 
> Thanks,
> Atsushi Kumagai
> 
> >Hi HATAYAMA,
> >
> >the average time of
> ># taskset -c 0,8 makedumpfile --num-threads 1 -d 31 vmcore vmcore-d31
> >is 33s.
> >the average time of
> ># taskset -c 0 makedumpfile -d 31 vmcore vmcore-d31
> >is 18s.
> >
> >My test steps:
> >1. change /etc/kdump/conf with
> >"core_collector makedumpfile -l --message-level 1 -d 31"
> >2. make a crash
> >3. cd into the directory of the vmcore made by kdump
> >4. in the directory of vmcore do
> ># taskset -c 0,8 makedumpfile --num-threads 1 -d 31 vmcore vmcore-d31
> >or
> ># taskset -c 0 makedumpfile -d 31 vmcore vmcore-d31
> >
> >if there are there any problems, please tell me.
> >
> >Thanks,
> >Chao Fan
> >
> >> >>
> >> >> Also, I'm assuming that you've done these benchmark on kdump 1st
> >> >> kernel, not kdump 2nd kernel. Is this correct?
> >> >>
> >> > Hi HATAYAMA,
> >> >
> >> > I test in the first kernel, not in the kdump second kernel.
> >> >
> >>
> >> I see.
> >>
> >> --
> >> Thanks.
> >> HATAYAMA, Daisuke
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> >>
> >
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