[mythtv-users] IOBOUND errors after kernel upgrade from 2.6.31 to 2.6.32

[Tom Dexter]

On Tue, Apr 27, 2010 at 10:16 AM, Tom Dexter <digitalaudiorock at gmail.com> wrote:
> On Tue, Apr 27, 2010 at 10:13 AM, Tom Dexter <digitalaudiorock at gmail.com> wrote:
>> On Sunday I did various updates on my Gentoo frontend/backend systems.
>>  Once of them was an upgrade from the 2.6.31 kernel to
>> 2.6.32...specifically sys-kernel/gentoo-sources-2.6.31-r6 to
>> sys-kernel/gentoo-sources-2.6.32-r7.
>>
>> I noticed a few skips in some recorded programs last night, like there
>> were small pieces missing.  I discovered that over the two nights
>> since that upgrade I've gotten several IOBOUND errors while recording.
>>  If I count just the "IOBOUND begin" messages I see 19 of them.
>>
>> I just unzipped all my old logs and can see that prior to that (all
>> the way back to February) I've had non at all.  There wasn't much of
>> anything else involved in the upgrade that I would expect to cause
>> those.  I've rebooted the backend to the 2.6.31 kernel and will see
>> how it goes tonight (I have a lot of recordings scheduled).  That
>> should tell me for sure whether or not the kernel is the issue.
>>
>> Is anyone aware of any new kernel settings that might affect
>> this...scheduler changes etc??
>>
>> Thanks.
>> Tom
>>
>
> I forgot to mention...I'm using EXT4 on my recording drive.  I
> converted from EXT3 at the beginning of March and that's been working
> fine.  Also, that's on an LVM2 volume.
>
> Tom
>

Just an update to this for anyone curious...

Since this happened to me i periodically tried new kernels as they
went stable under Gentoo but always had to revert to  2.6.31-r6 to
prevent IOBOUND errors.

I recently read parts of a discussion on kerneltrap.org that seemed to
indicate that the EXT4 preformance regression introduced in 2.6.32 (as
far as i can tell, actually in later versions of 2.6.31) was corrected
in newer 2.6.35 kernels.  I've now upgraded to 2.6.35-gentoo-r12 and
knock on wood, it seems great so far.  I've tried recording in all
three tuners at once and had no problems.

Tom