From: Juha Aatrokoski <jha-6fQLAAUwtFMxHbG02/KK1g@public.gmane.org>
To: Kent Overstreet <kmo-PEzghdH756F8UrSeD/g0lQ@public.gmane.org>
Cc: Heiko Wundram <modelnine-EqIAFqbRPK3NLxjTenLetw@public.gmane.org>,
linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: bcache hangs on writes, recovers after disabling discard on cache device
Date: Fri, 12 Jul 2013 19:13:43 +0300 (EEST) [thread overview]
Message-ID: <alpine.DEB.2.02.1307121902540.10602@orbit.lan> (raw)
In-Reply-To: <20130712011554.GA17799@kmo-pixel>
On Thu, 11 Jul 2013, Kent Overstreet wrote:
> On Thu, Jul 11, 2013 at 05:58:17PM +0300, Juha Aatrokoski wrote:
>> On Mon, 24 Jun 2013, Heiko Wundram wrote:
>>
>>> In a rather old thread of mine (514C4FC1.6090804-EqIAFqbRPK3NLxjTenLetw@public.gmane.org), I
>>> already stated a problem I was seeing back at the time, namely
>>> that bcache seems to hang on writes to the SSD device after some
>>> time, writing 50 MB/s continuously to the output device.
>> ...
>>> Disabling discard on the SSD device (by echo 0 >
>>> /sys/fs/bcache/.../cache0/discard) makes the bcache device become
>>> responsive again.
>>
>> I can confirm this. On Monday I booted into kernel 3.8.13-gentoo
>> with the current "bcache" branch patched onto it. Discard was on for
>> the cache device, and today this 50MB/s hang occured. Disabling
>> discard did indeed fix it.
>>
>> I had CONFIG_BCACHE_CLOSURES_DEBUG=y in the kernel, and the contents
>> of /sys/kernel/debug/bcache/bcache-UUID and
>> /sys/kernel/debug/closures both before and after disabling discard
>> can be found at the address below, in case they can help in
>> determining where exactly the hang happens.
>
> Can you give this patch a try? It's on top of the current
> bcache-for-3.11 branch
OK, now running the same kernel with this patch applied and discard
enabled. However, it has previously taken my system 2-4 days to trigger
this bug, so I'd say at least two weeks before I can say the patch (may
have) fixed the issue.
Heiko, can your setup reproduce this bug consistently in a shorter time?
If so, you could also try this patch for faster feedback.
next prev parent reply other threads:[~2013-07-12 16:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-24 18:36 bcache hangs on writes, recovers after disabling discard on cache device Heiko Wundram
[not found] ` <51C891C9.4060809-EqIAFqbRPK3NLxjTenLetw@public.gmane.org>
2013-07-11 14:58 ` Juha Aatrokoski
[not found] ` <alpine.DEB.2.02.1307111748130.26927-pfGh9vBu50j/PtFMR13I2A@public.gmane.org>
2013-07-12 1:15 ` Kent Overstreet
2013-07-12 16:13 ` Juha Aatrokoski [this message]
[not found] ` <alpine.DEB.2.02.1307121902540.10602-pfGh9vBu50j/PtFMR13I2A@public.gmane.org>
2013-07-16 18:14 ` Juha Aatrokoski
[not found] ` <alpine.DEB.2.02.1307162111590.3617-pfGh9vBu50j/PtFMR13I2A@public.gmane.org>
2013-07-16 21:05 ` Kent Overstreet
2013-07-18 12:05 ` Juha Aatrokoski
[not found] ` <alpine.DEB.2.02.1307181458180.18577-pfGh9vBu50j/PtFMR13I2A@public.gmane.org>
2013-07-18 17:53 ` Kent Overstreet
2013-07-18 21:02 ` Juha Aatrokoski
2013-07-26 18:44 ` Juha Aatrokoski
[not found] ` <alpine.DEB.2.02.1307262143200.22718-pfGh9vBu50j/PtFMR13I2A@public.gmane.org>
2013-07-26 20:13 ` Kent Overstreet
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