On 08/18/2011 02:44 AM, youagree wrote:
Also, a patch by Josef Bacik was an attempt for fixing this, but no one
reported about testing it on an affected system, it did not eliminate
the slowdowns for me:
PLEASE TEST: Everybody who is seeing weird and long hangs
news://news.gmane.org:119/4E36C47E.70309@xxxxxxxxxx
I had not seen this (actually, I had skimmed it but not thought it was
relevant). I will try it as soon as I get a chance.
The HDD thrashing appeared on all other kernel versions I tried, higher
than 2.6.37.
Initially, I had been into looking for a latest known good kernel (to
prepare a proper git bisect as cwillu advised) and at first I also felt
like 2.6.38 does not show this miserable behaviour. But later it turned
out this was only for approximately 2 days of uptime. Given enough time,
the lock-ups appeared on 2.6.38 too. Although they were not that
apparent than on later kernel versions, and the individual lockups took
much less time with 2.6.38 running for 2 days (binary Sabayon Linux
repository kernel).
I have not seen slowdowns on 2.6.38. More specifically, I observe the following
behaviors after commit 4e69b59:
* Many processes occasionally hang for a short time
* When this happens, my cpu monitor shows a short burst of cpu activity (100% of
1 core) followed by a longer period of IO
* When this happens, iotop shows [btrfs-submit-0] and [btrfs-transacti] at the
top of the list
* Behavior slowly increases in duration (and frequency?) over time, and goes
away with a reboot
* Heavy IO makes behavior appear faster
... and the following behaviors before commit 4e69b59:
* Occasional spikes of IO on cpu monitor concurrent with [btrfs-submit-0] and
[btrfs-transacti] at top of iotop
* No hangs, even when that occurs
I wasn't taking notes or anything though, so I'm not 100% certain I was
observing or interpreting or remembering everything correctly.
--Andrew
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
