From: caiqian@redhat.com
To: linux-mm <linux-mm@kvack.org>
Subject: understand KSM
Date: Mon, 25 Oct 2010 05:11:05 -0400 (EDT) [thread overview]
Message-ID: <1877317998.247611287997865214.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> (raw)
In-Reply-To: <356409918.247361287997619777.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
Hi everyone, while developing some tests for KSM in LTP - http://marc.info/?l=ltp-list&m=128754077917739&w=2 , noticed that pages_shared, pages_sharing and pages_unshared have different values than the expected values in the tests after read the doc. I am not sure if I misunderstood those values or there were bugs somewhere.
There are 3 programs (A, B ,C) to allocate 128M memory each using KSM.
A has memory content equal 'c'.
B has memory content equal 'a'.
C has memory content equal 'a'.
Then (using the latest mmotm tree),
pages_shared = 2
pages_sharing = 98292
pages_unshared = 0
Later,
A has memory content = 'c'
B has memory content = 'b'
C has memory content = 'a'.
Then,
pages_shared = 4
pages_sharing = 98282
pages_unshared = 0
Finally,
A has memory content = 'd'
B has memory content = 'd'
C has memory content = 'd'
Then,
pages_shared = 0
pages_sharing = 0
pages_unshared = 0
The following was the failed LTP output,
# ./ksm01
ksm01 0 TINFO : KSM merging...
ksm01 0 TINFO : child 0 allocates 128 MB filled with 'c'.
ksm01 0 TINFO : child 1 allocates 128 MB filled with 'a'.
ksm01 0 TINFO : child 2 allocates 128 MB filled with 'a'.
ksm01 0 TINFO : check!
ksm01 0 TINFO : run is 1.
ksm01 0 TINFO : pages_shared is 2.
ksm01 1 TFAIL : pages_shared is not 32768.
ksm01 0 TINFO : pages_sharing is 98292.
ksm01 2 TFAIL : pages_sharing is not 32768.
ksm01 0 TINFO : pages_unshared is 0.
ksm01 3 TFAIL : pages_unshared is not 32768.
ksm01 0 TINFO : child 1 continues...
ksm01 0 TINFO : child 1 changes memory content to 'b'.
ksm01 0 TINFO : check!
ksm01 0 TINFO : run is 1.
ksm01 0 TINFO : pages_shared is 4.
ksm01 4 TFAIL : pages_shared is not 0.
ksm01 0 TINFO : pages_sharing is 98282.
ksm01 5 TFAIL : pages_sharing is not 0.
ksm01 0 TINFO : pages_unshared is 0.
ksm01 6 TFAIL : pages_unshared is not 98304.
ksm01 0 TINFO : child 0 continues...
ksm01 0 TINFO : child 0 changes memory content to 'd'.
ksm01 0 TINFO : child 1 continues...
ksm01 0 TINFO : child 1 changes memory content to 'd'
ksm01 0 TINFO : child 2 continues...
ksm01 0 TINFO : child 2 changes memory content to 'd'
ksm01 0 TINFO : check!
ksm01 0 TINFO : run is 1.
ksm01 0 TINFO : pages_shared is 0.
ksm01 7 TFAIL : pages_shared is not 32768.
ksm01 0 TINFO : pages_sharing is 0.
ksm01 8 TFAIL : pages_sharing is not 65536.
ksm01 0 TINFO : pages_unshared is 0.
ksm01 0 TINFO : KSM unmerging...
ksm01 0 TINFO : check!
ksm01 0 TINFO : run is 2.
ksm01 0 TINFO : pages_shared is 0.
ksm01 0 TINFO : pages_sharing is 0.
ksm01 0 TINFO : pages_unshared is 0.
ksm01 0 TINFO : stop KSM.
ksm01 0 TINFO : check!
ksm01 0 TINFO : run is 0.
ksm01 0 TINFO : pages_shared is 0.
ksm01 0 TINFO : pages_sharing is 0.
ksm01 0 TINFO : pages_unshared is 0.
ksm01 9 TFAIL : ksmtest() failed with 1.
CAI Qian
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next parent reply other threads:[~2010-10-25 9:11 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <356409918.247361287997619777.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
2010-10-25 9:11 ` caiqian [this message]
2010-10-26 8:03 ` understand KSM Hugh Dickins
2010-10-26 11:14 ` CAI Qian
2010-10-27 4:00 ` Hugh Dickins
[not found] <395413139.534301288167215758.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
2010-10-27 8:16 ` caiqian
2010-11-09 6:48 ` Hugh Dickins
2010-11-10 9:25 ` CAI Qian
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