[mythtv-users] Mythbackend causing high load
Dan Milne
d at nmilne.com
Mon Jun 26 10:08:11 UTC 2006
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Hi All,
I'm also using Reiserfs on the partition MythTV is using. For
the record I'm using the FlexCopII (B2C2) Adapters. I've also turned
off transcoding and am still experiencing the problem load peaking
between 10 - 20.
Cheers,
Dan
On 26/06/2006, at 13:12 , Mike Benoit wrote:
> NOTE: I'm cc'ing this to the ReiserFS list, as it appears to be
> related.
>
> I finally got around to profiling mythbackend when the load starts to
> spike up around 10. To my surprise it appears that reiserfs is the
> culprit, maybe the ReiserFS guys have some input as to what is causing
> this?
>
> #opreport
> CPU: CPU with timer interrupt, speed 0 MHz (estimated)
> Profiling through timer interrupt
> TIMER:0|
> samples| %|
> ------------------
> 77863 78.7856 reiserfs
> 18183 18.3984 vmlinux
> 695 0.7032 mysqld
> 452 0.4574 libc-2.4.so
> 360 0.3643 libmythtv-0.19.so.0.19.0
> 324 0.3278 ivtv
> 323 0.3268 nvidia
> 242 0.2449 libqt-mt.so.3.3.6
> 110 0.1113 libpthread-2.4.so
> 53 0.0536 libstdc++.so.6.0.8
> 35 0.0354 ld-2.4.so
> 23 0.0233 libperl.so
> 22 0.0223 libz.so.1.2.3
> <snip>
>
> #opreport -l /usr/src/linux/vmlinux
> CPU: CPU with timer interrupt, speed 0 MHz (estimated)
> Profiling through timer interrupt
> samples % symbol name
> 9607 52.8351 default_idle
> 7694 42.3142 find_next_zero_bit
> 183 1.0064 __copy_from_user_ll
> 57 0.3135 handle_IRQ_event
> 37 0.2035 __copy_to_user_ll
> 34 0.1870 ide_outb
> 30 0.1650 ide_end_request
> 22 0.1210 ioread8
> 22 0.1210 schedule
> 21 0.1155 get_page_from_freelist
> 17 0.0935 mmx_clear_page
> <snip>
>
> System Details:
> -----------------------------------------------
> Kernel v2.6.16.21 (custom compiled)
> - This issue also happened with 2.6.14 too though.
>
> Filesystem Size Used Avail Use% Mounted on
> /dev/hda1 280G 269G 12G 97% /
>
> [root at mythtv]# cat /proc/mounts
> rootfs / rootfs rw 0 0
> /dev /dev tmpfs rw 0 0
> /dev/root / reiserfs rw,noatime,nodiratime 0 0
>
> [root at mythtv]# cat /proc/cpuinfo
> processor : 0
> vendor_id : AuthenticAMD
> cpu family : 6
> model : 6
> model name : AMD Athlon(tm) XP 2100+
> stepping : 2
> cpu MHz : 1759.680
> cache size : 256 KB
>
> [root at mythtv]# free
> total used free shared buffers
> cached
> Mem: 515992 496256 19736 0 36256
> 271728
> -/+ buffers/cache: 188272 327720
> Swap: 262136 408 261728
>
>
> Syslog:
> -------------------------------------------------
> Jun 25 19:52:22 mythtv kernel: ivtv1: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:52:22 mythtv kernel: ivtv1: Cause: the application is not
> reading fast enough.
> Jun 25 19:52:57 mythtv kernel: ivtv1: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:52:57 mythtv kernel: ivtv1: Cause: the application is not
> reading fast enough.
> Jun 25 19:53:00 mythtv kernel: ivtv0: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:53:00 mythtv kernel: ivtv0: Cause: the application is not
> reading fast enough.
> Jun 25 19:53:32 mythtv kernel: ivtv1: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:53:32 mythtv kernel: ivtv1: Cause: the application is not
> reading fast enough.
> Jun 25 19:53:35 mythtv kernel: ivtv0: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:53:35 mythtv kernel: ivtv0: Cause: the application is not
> reading fast enough.
> Jun 25 19:54:01 mythtv kernel: ivtv1: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:54:01 mythtv kernel: ivtv1: Cause: the application is not
> reading fast enough.
> Jun 25 19:54:16 mythtv kernel: ivtv0: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:54:16 mythtv kernel: ivtv0: Cause: the application is not
> reading fast enough.
> Jun 25 19:54:36 mythtv kernel: ivtv1: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:54:36 mythtv kernel: ivtv1: Cause: the application is not
> reading fast enough.
> Jun 25 19:54:47 mythtv kernel: ivtv0: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:54:47 mythtv kernel: ivtv0: Cause: the application is not
> reading fast enough.
> Jun 25 19:55:08 mythtv kernel: ivtv1: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:55:08 mythtv kernel: ivtv1: Cause: the application is not
> reading fast enough.
> Jun 25 19:55:19 mythtv kernel: ivtv0: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:55:19 mythtv kernel: ivtv0: Cause: the application is not
> reading fast enough.
> Jun 25 19:55:39 mythtv kernel: ivtv1: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:55:39 mythtv kernel: ivtv1: Cause: the application is not
> reading fast enough.
> Jun 25 19:55:57 mythtv kernel: ivtv0: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:55:57 mythtv kernel: ivtv0: Cause: the application is not
> reading fast enough.
> Jun 25 19:56:11 mythtv kernel: ivtv1: All encoder MPEG stream buffers
> are full. Dropping data.
> Jun 25 19:56:11 mythtv kernel: ivtv1: Cause: the application is not
> reading fast enough.
> Jun 25 19:56:33 mythtv kernel: ivtv0: All encoder MPEG stream buffers
> are full. Dropping data.
>
>
> mythbackend log:
> --------------------------------------------------------
> 2006-06-25 19:51:43.906 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:44.836 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:44.842 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:45.022 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:45.028 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:46.123 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:46.129 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:47.500 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:48.094 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:48.099 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:48.370 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:48.376 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:48.922 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:48.928 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:50.650 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:50.657 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:50.660 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:50.697 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:52.195 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:52.201 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:52.450 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:52.457 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:54.369 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:54.375 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:54.644 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:54.650 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:55.423 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:55.429 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:56.057 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:56.063 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:56.481 TFW, Error: Write() -- IOBOUND end
> 2006-06-25 19:51:56.487 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> free(2047)
> 2006-06-25 19:51:57.746 TFW, Error: Write() -- IOBOUND end
>
>
> On Fri, 2006-06-16 at 12:58 -0500, Stuart Larson wrote:
>> I've seen this sort of behavior when recoding or transcoding
>> (doesn't seem
>> to make a difference which) when my free space on drive was close
>> to what
>> Myth is set to keep free - I have Myth set to keep 20G free, and
>> when it
>> reached around 22-23G free, I started seeing this behavior (I'm
>> running
>> reiserfs, so the xfs space-free thing shouldn't be an issue). Not
>> sure if
>> it would be related... The recordings did work fine (PVR-250), but
>> watching while recording doesn't work very well.
>>
>>> I'm seeing something very familiar, mythbackend uses about 100% CPU
>>> during a recording and though not always, I sometimes see IOBOUND
>>> errors
>>> in the log. I have transcode/commflag jobs set to run after midnight
>>> each day, and no other processes are using CPU while mythbackend is
>>> hogging it all.
>>>
>>> The weird thing is my box was running fine for a few months prior
>>> to a
>>> power outage. After the outage I booted up the box and I started to
>>> notice IVTV buffer overflows happening during every recording
>>> causing
>>> the load to spike up to 10+ during each recording. The recording was
>>> useless of course too. This was with IVTV 0.4.1 on a PVR-500.
>>>
>>> So I decided to upgrade to IVTV 0.4.5 to see if that solved the
>>> problem.
>>> Well, I no longer see IVTV buffer overflow messages in the log,
>>> but now
>>> mythbackend uses 100% CPU. I upgraded to the latest SVN snapshot of
>>> 019-fixes branch to see if that helped at all, but it didn't.
>>>
>>> So now mythbackend uses 100% CPU, the recordings seem to be working
>>> fine, but I can't watch any recordings while this is happening.
>>>
>>> I'm running an Athlon 2100 with kernel 2.6.14.
>>>
>>> Just last week I could have two recordings going at once,
>>> mythcomm flag
>>> running in real-time, and two frontends both watching recordings
>>> with no
>>> issues at all. Now one recording at a time and NOTHING else is
>>> all that
>>> can happen. :(
>>>
>>> Does anyone know what I can do to try and track this issue down?
>>>
>>> Thanks.
>>>
>>> On Fri, 2006-06-16 at 06:41 -0400, Jeff wrote:
>>>> On 6/15/06, Ryan Steffes <rbsteffes at gmail.com> wrote:
>>>>
>>>>> Do you, by any chance, have a slave to offload the transcode onto?
>>>> Try
>>>>> disabling transcode jobs on that backend, and see if it comes
>>>>> back.
>>>> Mine
>>>>> hasn't since then, even though it's a less than ideal fix.
>>>>>
>>>>
>>>> For the most part I don't do transcoding. I do have a 'transcode
>>>> for
>>>> ipod'
>>>> job which seems to have gotten itself attached to every
>>>> recording (it
>>>> was
>>>> only supposed to be one show) but I don't think its working at the
>>>> moment.
>>>>
>>>> I do commercial flagging though at the end of each show.
>>>>
>>>> I can try moving this to a slave backend.
>>>> _______________________________________________
>>>> mythtv-users mailing list
>>>> mythtv-users at mythtv.org
>>>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>> --
>>> Mike Benoit <ipso at snappymail.ca>
>>> _______________________________________________
>>> mythtv-users mailing list
>>> mythtv-users at mythtv.org
>>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>>
>>
>>
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users at mythtv.org
>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> --
> Mike Benoit <ipso at snappymail.ca>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
- ---
Dan Milne d at nmilne.com
http://politiwiki.kicks-ass.net/
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