getting particular thread cpu time
Julian Elischer
julian at elischer.org
Wed Feb 1 12:31:59 PST 2006
Daniel Eischen wrote:
>On Wed, 1 Feb 2006, Julian Elischer wrote:
>
>
>
>>Daniel Eischen wrote:
>>
>>
>>
>>>Libpthread is M:N by default, so the kernel doesn't know about
>>>userland threads.
>>>
>>>
>>>
>>>
>>though we might think about ways that we can get that information..
>>maybe a way that the user thread scheduler can be asked for the info?
>>
>>
>
>We don't currently maintain per-thread system and user time.
>It's not just that either, there has to be some way to identify
>each thread and the kernel would need that info (name, thread
>id, ??) also. You _could_ add pthread_getrusage_np(), or
>something like that, to the threads libraries which would
>make it visible to the application, but I hesitate to think
>this information would be useful to the kernel so that ps
>and top can show it. I think ps and top should just show
>the kernel entities and that's it. I wouldn't strongly
>oppose making these utilities show userland thread info
>as long as it didn't impact performance.
>
>
I was thinking of a tool to help developers do usage monitoring on their
programs.
as a debugging aid..
We DO put usage information into the KSE mailbox do we not?
when you come back from a kernel call you should find stats there from
memory.
(however I'm not going to go look now as I need to get on with $REALJOB
and have promised myself that this will wait until I get enough time to
do teh stats properly.
More information about the freebsd-threads
mailing list