lists.openwall.net   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:	Fri, 12 Dec 2008 13:37:30 +0100
From:	"Gilles.Carry" <Gilles.Carry@....bull.net>
To:	"Ma, Chinang" <chinang.ma@...el.com>
Cc:	Ingo Molnar <mingo@...e.hu>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"Wilcox, Matthew R" <matthew.r.wilcox@...el.com>,
	"Van De Ven, Arjan" <arjan.van.de.ven@...el.com>,
	"Styner, Douglas W" <douglas.w.styner@...el.com>,
	"Chilukuri, Harita" <harita.chilukuri@...el.com>,
	"Wang, Peter Xihong" <peter.xihong.wang@...el.com>,
	"Nueckel, Hubert" <hubert.nueckel@...el.com>
Subject: Re: CFS scheduler OLTP perforamnce

Ma, Chinang a écrit :
> We are evaluating the CFS OLTP performance with 2.6.28-c7 kernel. In this workload once a database foreground process commit a transaction it will signal the log writer process to write to the log file. Foreground processes will wait until log writer finish writing and wake them up. With hundreds of foreground process running in the system, it is important that the log writer get to run as soon as data is available. 
> 
> Here are the experiments we have done with 2.6.28-rc7.
> 1. Increase log writer priority "renice -20 <log writer pid>" while keeping all other processes running in default CFS priority. We get a baseline performance with log latency (scheduling + i/o) at 7 ms.
> 
> 2. To reduce log latency, we set log writer to SCHED_RR with higher priority. We tried "chrt -p 49  <log writer pid>" and got 0.7% boost in performance with log latency reduced to 6.4 ms.
> 
> It seems that in this case renice to higher priority with CFS did not reduce scheduling latency as well as SCHED_RR.

Maybe you should try an RT kernel.

Gilles.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists