linux-kernel - Interesting interaction between lguest and CFS

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-next>] [day] [month] [year] [list]

Date:	Mon, 4 Jun 2007 12:37:10 -0500
From:	Matt Mackall <mpm@...enic.com>
To:	Ingo Molnar <mingo@...e.hu>, Rusty Russell <rusty@...tcorp.com.au>,
	akpm@...ux-foundation.org
Cc:	Linux-kernel@...r.kernel.org
Subject: Interesting interaction between lguest and CFS

With 2.6.22-rc3-mm1, I've got a long-running video transcoding going
on. In other windows, I'm compiling, reading email, etc. with no
noticeable problems.

If I fire up lguest and leave it sitting at a shell prompt for a
couple moments, when I return to type something at the prompt, it can
take 2-3 seconds for my input to echo. Once it starts responding,
typing latency disappears. Suspend the other app and the latency
disappears.

The system isn't swapping and has basically no I/O load.

Ok, my transcoding just finished as I was writing this. So I've
reproduced the problem with this Python script that I had handy:

memload.py:
#!/usr/bin/python
a = "a" * 16 * 1024 * 1024
while 1:
    b = a[1:] + "b"
    a = b[1:] + "c"

-- 
Mathematics is the supreme nostalgia of our time.
-
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/