linux-kernel - RE: 2.6.25.4-rt2

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.58.0805200945120.12041@gandalf.stny.rr.com>
Date:	Tue, 20 May 2008 09:54:06 -0400 (EDT)
From:	Steven Rostedt <rostedt@...dmis.org>
To:	MA QING A <Qing.a.Ma@...atel-sbell.com.cn>
cc:	Kasper Sandberg <lkml@...anurb.dk>,
	LKML <linux-kernel@...r.kernel.org>,
	RT <linux-rt-users@...r.kernel.org>, Ingo Molnar <mingo@...e.hu>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: RE: 2.6.25.4-rt2

Hi,

[
  It seems that you may be new to the lists, so I will let you know,
  please do not top post. It is appropriate to either bottom post or
  better yet, inline reply. See http://en.wikipedia.org/wiki/Posting_style
]

On Tue, 20 May 2008, MA QING A wrote:

> Thanks very much for your explanation
> At the very beginning I thought the Hackbench was a latency tools, so
> I was very surprised to see such result.
>
> But there's another question. When I choose the Complete Preemption
> -Real Time  configuration, it's recommended to choose Timer Frequency
> ---> 1000Mhz to improve the cpu performance, does it mean cpu will cost
> much more during the thread context switch? Or I should choose 100Mhz in
> order to decrease the thread context switch and get a better
> performance?
>
> Which one should I choose? Or any useful tools can tell me the differences.
>

I'm not sure where you read that. With the introduction of high-resolution
timers, the HZ value isn't that important anymore. Things that might use
select or poll as timeouts will still be at the HZ frequency, but other
code that uses proper timer API will still react well.

Matters what you are doing. Try out different values yourself and see what
you find is the best. You can also report your findings if you want.

Cheers,

-- Steve

--
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/