lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Thu, 23 Feb 2012 16:50:05 +0530
From:	Srivatsa Vaddagiri <>
To:	Mike Galbraith <>
Cc:	Peter Zijlstra <>,
	Suresh Siddha <>,
	linux-kernel <>,
	Ingo Molnar <>, Paul Turner <>
Subject: Re: sched: Avoid SMT siblings in select_idle_sibling() if possible

* Srivatsa Vaddagiri <> [2012-02-23 16:19:59]:

> > Enabling SD_BALANCE_WAKE used to be decidedly too expensive to consider.
> > Maybe that has changed, but I doubt it.  (general aside: testing with a
> > bloated distro config is a big mistake)
> I am seeing 2.6% _improvement_ in volanomark score by enabling SD_BALANCE_WAKE
> at SMT/MC domains.

Ditto with pipe benchmark.

> Machine : 2 Quad-core Intel X5570 CPU (H/T enabled)
> Kernel  : tip (HEAD at 6241cc8)

"perf bench sched pipe" was run 10 times and average ops/sec score
alongwith std. dev is noted as below.

		 disabled		enabled

Avg. score	108984.900 		111844.300 (+2.6%)
std dev		20383.457		21668.604


SD_BALANCE_WAKE for SMT/MC domain was enabled by writing into appropriate 
flags file present in /proc:

	# cd /proc/sys/kernel/sched_domain/
	# for i in `find . -name flags | grep domain1`; do echo 4671 > $i; done
	# for i in `find . -name flags | grep domain0`; do echo 703 > $i; done

- vatsa

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists