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From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Eric Dumazet <edumazet@google.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Gao feng <gaofeng@cn.fujitsu.com>
Subject: Hack bench regression with CONFIG_SLUB_CPU_PARTIAL disabled (info only)
Date: Thu, 25 Jul 2013 13:30:17 +0530	[thread overview]
Message-ID: <51F0DB11.2080508@linux.vnet.ibm.com> (raw)

Hi,

While testing hackbench with 3.11-rc1 I observed hackbench testcase
took too long to complete (32 vcpu kvm guest on 32 core HT off machine).

hackbench 1x degraded by 3 time (40sec vs 112sec)
hackbench 2x degraded by around 20time (90sec vs 1800 sec)

When I bisected, I found that I had CONFIG_SLUB_CPU_PARTIAL
accidentally disabled.
I understand that  CONFIG_SLUB_CPU_PARTIAL=y by default and the config
option is to provide determinism for RT kernels and thus it is not a
problem.
But thought of sharing this here so that if somebody runs into same 
issue accidently, it would save their time.

             reply	other threads:[~2013-07-25  8:00 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-25  8:00 Raghavendra K T [this message]
2013-07-25 11:05 ` Eric Dumazet
2013-07-25 13:20   ` Raghavendra K T

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