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fscopy test case needs improvements #19

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GoogleCodeExporter opened this issue May 7, 2015 · 1 comment
Open

fscopy test case needs improvements #19

GoogleCodeExporter opened this issue May 7, 2015 · 1 comment

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@GoogleCodeExporter
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What steps will reproduce the problem?
1. fscopy test cases

What is the expected output? What do you see instead?

1. The test cases with a biggest file of 4096 buffer and 8000 blocks is ~ 32MB 
file size. When I run this on a Haswell server (Intel(R) Xeon(R) CPU E5-2690 
v3), this fits entirely in the L3 memory when I run only one guest. Even though 
the test case might be valid the enviroment or scenario where only one guest is 
running will give undue advantage as L3 is shared. This requires that the size 
of file be increased

2. I tried a cp command on ubuntu 15.04 on a file which contains only "0" as 
contents

read(3, "0\n", 131072)                  = 2
write(4, "0\n", 2)                      = 2

and I see that it uses a buffer size of 128k. I also noticed the same on ppc64 
version of ubuntu15.04

 So, the buffer size also needs to be increased.

What version of the product are you using? On what operating system?

ubuntu 5.1.3 / ubuntu 15.04 (ext4)

Please provide any additional information below.

In RHEL 7.0 (xfs) the cp command uses 64k buffer size.
So, it is necessary that the buffer and block size be increased.



Original issue reported on code.google.com by [email protected] on 30 Mar 2015 at 1:39

@voellm
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voellm commented Jun 4, 2015

Do you have any suggested fix?

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