I've been noticing this symptom for a while now especially when running
programs that copy large files using large buffer sizes. It's worse
than just firefox, as the entire desktop will freeze for minutes at a time.
This change/workaround cleared this up entirely for me. If we haven't
incorporated this yet, we should consider doing so.
-------- Original Message --------
Subject: Re: [Cooker] System can stall under heavy IOs with slow
storage devices
Date: Mon, 19 Dec 2011 19:36:02 +0100
From: Florian Hubold <[email protected]>
Reply-To: [email protected]
To: [email protected]
Am 19.12.2011 10:26, schrieb Franck Bui:
Hello,
I've noticed a regression on my system which can stall some applications
(most notably firefox) during very very long time (> 10 mins).
Man, you're my hero, trying to find out what causes this since some months now.
At least two thumbs up! :)
It's apparently related to transparent huge pages and I found that it
had already been described by LWN here a month ago:
http://lwn.net/Articles/467328/.
Unlike what it's stated in the article, the regression is not really
hard to trigger in my case: just plug a USB stick, copy on it a big
file, then try to use firefox...
To fix this, simply try to disable THP:
echo madvise>/sys/kernel/mm//transparent_hugepage/enabled
and firefox should work as expected now.
So, if no one objects, the plan is to simply default the THP stuff to
"madvise" for desktop flavour where an application has to ask
explicitly huge page otherwise it will be disabled.
