On 06/22/2011 11:57 AM, Calvin Walton wrote: > On Wed, 2011-06-22 at 11:39 -0400, Josef Bacik wrote: >> On 06/22/2011 10:15 AM, Henning Rohlfs wrote: >>> On Tue, 21 Jun 2011 11:24:11 -0400, Calvin Walton wrote: >>>> On Mon, 2011-06-20 at 23:51 +0200, Henning Rohlfs wrote: >>>>> Hello, >>>>> >>>>> I've migrated my system to btrfs (raid1) a few months ago. Since then >>>>> the performance has been pretty bad, but recently it's gotten >>>>> unbearable: a simple sync called while the system is idle can take >>>>> 20 up >>>>> to 60 seconds. Creating or deleting files often has several seconds >>>>> latency, too. >>>> >>>> I think I’ve been seeing a fairly similar, or possibly the same? issue >>>> as well. It looks like it’s actually a regression introduced in 2.6.39 - >>>> if I switch back to a 2.6.38 kernel, my latency issues magically go >>>> away! (I'm curious: does using the older 2.6.38.x kernel help with >>>> anyone else that's seeing the issue?) > >>>> I think I can reproduce the issue well enough to bisect it, so I might >>>> give that a try. It'll be slow going, though. >>> >>> You are right. This seems to be a regression in the .39 kernel. I tested >>> with 2.6.38.2 just now and the performance is back to normal. >> >> Would you mind bisecting? > > Just before I was going to try bisecting, I tried the 3.0-rc4 kernel out > of curiosity. And it seems to be quite a bit better; at the very least, > I’m not seeing gui applications stalling for ~10 seconds when doing > things like opening or writing files. Latencytop is reporting fsync() > latencies staying pretty steady in the range of under 300ms, with > occasional outliers at up to 2s, and it's not getting worse with time. > > I'll still look into doing a bisect between 2.6.38 and 2.6.39, I'm > curious what went wrong. >
Yeah that makes two of us :). There were some other plugging changes that went into to 38, so maybe bisect all of the kernel, not just fs/ just in case it was those and not us. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
