[mythtv-users] Mythfrontend idle cpu consumption help

[Michael T. Dean]

On 11/11/2009 12:49 PM, Jim Stichnoth wrote:
> On Wed, Nov 11, 2009 at 8:43 AM, Johnny wrote:
>   
>> Now back to the CPU usage. What is the right approach to understanding
>> this or to giving the devs something informative and actionable. I
>> have tried strace as was suggested. But that just shows system calls,
>> I don't know how helpful that is. I get this over and over again:
>>
>> clock_gettime(CLOCK_MONOTONIC, {3769, 150476635}) = 0
>> read(8, 0x8b3bd00, 4096)                = -1 EAGAIN (Resource
>> temporarily unavailable)
>> gettimeofday({1257956725, 614018}, NULL) = 0
>> clock_gettime(CLOCK_MONOTONIC, {3769, 150674908}) = 0
>> read(8, 0x8b3bd00, 4096)                = -1 EAGAIN (Resource
>> temporarily unavailable)
>> read(17, 0x8b72f60, 4096)               = -1 EAGAIN (Resource
>> temporarily unavailable)
>> gettimeofday({1257956725, 614218}, NULL) = 0
>>
>> And when I look at the count (strace -c), it looks like it spends most
>> of its CPU time in those read() calls that are failing. However, I
>> haven't done this kind of debugging before and I don't want to waste
>> time if this isn't even relevent.
>>     
> That's pretty much what I'm seeing in my reasonably working system.
> You might add the "-tt" flag to strace to add timestamps to the
> output, and verify that this pattern is repeating about 70 times per
> second.

If there /is/ a bug related to this, it's in Qt or your libc or ...

Hey, didn't *buntu just switch libc's to eglibc?

Regardless, the system calls you're seeing above are coming from Qt 
code, not Myth code.

Mike