Hi Eddie, Some info that I'm sure will help debugging. I configured click with --enable-schedule-debugging=extra and also enabled NOTIFIERQUEUE_DEBUG
It seems Unqueue gets stuck in the pending list. See the output below: read q.length 1000 read q.notifier_state notifier on task 0x19387b0 [uq :: Unqueue] scheduled read uq.scheduled true /* but pending */ read uq.notifier empty.0/1:1* Unqueue stays in this scheduled but pending state for an undetermined period of time, up to minutes some times. Any idea where I can start on fixing this bug? Beyers On Wed, Feb 9, 2011 at 2:52 AM, Beyers Cronje <[email protected]> wrote: > Update - Strange, after typing my previous email I checked again, and all > of a sudden Unqueue was pulling packets again. Not sure if me breaking into > Click with gdb kick-started, it again :) or if it's a intermittent issue. > > > On Wed, Feb 9, 2011 at 2:41 AM, Beyers Cronje <[email protected]> wrote: > >> Hi Eddie, >> >> Since running this merge I've been experiencing issues with usermode >> multithreading. I'm using commit 9419098acbdc20837e37f3033c40661809431f8d >> I do believe the issues are related to the changes of this merged, as I >> was running the same config on pre-coreperformance merge code without any >> issues. >> >> *Simplified Config used:* >> >> fd::FromDAG(/dev/dag0) -> cl1::Classifier(12/0800) -> MarkIPHeader(14) -> >> ipc1::IPClassifier(udp port 1646); >> sfp::SFP(); >> q::ThreadSafeQueue; >> log::Logger(sfp, 1800); >> >> ipc1 -> RadAccounting -> q; >> q -> uq::Unqueue -> aupcc::Counter -> sfp; >> >> StaticThreadSched(fd 0, uq 1, log 2); >> >> *Problem Description:* >> The 3 threads in the config: FromDAG and Unqueue do what their names >> indicate, and Logger has a timer that schedules its task once every 30min. >> Everything runs fine initially and then somewhere along the line Unqueue >> stops pulling packets from the queue which leads to a constant queue >> overflow. When this happens I can see FromDAG is still working as q.drops >> increases constantly, and Logger also fires away every 30min. Note push rate >> from FromDAG is quite high, but what RadAccounting pushes into queue is very >> low ~ 100pps, which means queue is most of the time empty and Unqueue is not >> scheduled. >> >> Unfortunately I didn't configure debug scheduling, which would've helped. >> I did notice Unqueue.scheduled always returned true, even though it never >> actually ran. Not sure if the following will help, gdb shows the following: >> >> (gdb) info threads >> 3 Thread 0x7fa422559700 (LWP 27205) 0x000000392cedb0b3 in poll () from >> /lib64/libc.so.6 >> 2 Thread 0x7fa421d58700 (LWP 27206) 0x000000392cedcee3 in select () >> from /lib64/libc.so.6 >> * 1 Thread 0x7fa432cfb740 (LWP 27197) FromDAG::process_packet >> (this=0x1afc570, erf_record=0x7fa423258bf0, rlen=<value optimized out>) at >> ../elements/local/fromdag.cc:193 >> (gdb) thread 2 >> [Switching to thread 2 (Thread 0x7fa421d58700 (LWP 27206))]#0 >> 0x000000392cedb0b3 in poll () from /lib64/libc.so.6 >> (gdb) bt >> #0 0x000000392cedb0b3 in poll () from /lib64/libc.so.6 >> #1 0x000000000058bc36 in Master::run_selects_poll (this=0x1afacc0, >> thread=0x1afb8b0, more_tasks=false) at ../lib/master.cc:862 >> #2 0x000000000058c4ec in Master::run_selects (this=0x1afacc0, >> thread=0x1afb8b0) at ../lib/master.cc:1050 >> #3 0x000000000057ddf1 in run_os (this=0x1afb8b0) at >> ../lib/routerthread.cc:447 >> #4 RouterThread::driver (this=0x1afb8b0) at ../lib/routerthread.cc:568 >> #5 0x0000000000556dc9 in thread_driver (user_data=<value optimized out>) >> at click.cc:414 >> #6 0x000000392d206d5b in start_thread () from /lib64/libpthread.so.0 >> #7 0x000000392cee4aad in clone () from /lib64/libc.so.6 >> (gdb) thread 3 >> [Switching to thread 3 (Thread 0x7fa422559700 (LWP 27205))]#0 >> 0x000000392cedcee3 in select () from /lib64/libc.so.6 >> (gdb) bt >> #0 0x000000392cedcee3 in select () from /lib64/libc.so.6 >> #1 0x000000000058c4bf in Master::run_selects (this=0x1afacc0, >> thread=0x1afb7e0) at ../lib/master.cc:1015 >> #2 0x000000000057ddf1 in run_os (this=0x1afb7e0) at >> ../lib/routerthread.cc:447 >> #3 RouterThread::driver (this=0x1afb7e0) at ../lib/routerthread.cc:568 >> #4 0x0000000000556dc9 in thread_driver (user_data=<value optimized out>) >> at click.cc:414 >> #5 0x000000392d206d5b in start_thread () from /lib64/libpthread.so.0 >> #6 0x000000392cee4aad in clone () from /lib64/libc.so.6 >> (gdb) thread 1 >> [Switching to thread 1 (Thread 0x7fa432cfb740 (LWP 27197))]#0 >> 0x000000392d20ebfd in nanosleep () from /lib64/libpthread.so.0 >> (gdb) bt >> #0 FromDAG::process_packet (this=0x1afc570, erf_record=0x7fa423258bf0, >> rlen=<value optimized out>) at ../elements/local/fromdag.cc:193 >> #1 0x00000000004d6402 in FromDAG::run_task (this=0x1afc570) at >> ../elements/local/fromdag.cc:150 >> #2 0x000000000057dbe6 in fire (this=0x1afb710) at >> ../include/click/task.hh:612 >> #3 run_tasks (this=0x1afb710) at ../lib/routerthread.cc:410 >> #4 RouterThread::driver (this=0x1afb710) at ../lib/routerthread.cc:600 >> #5 0x0000000000558513 in main (argc=<value optimized out>, argv=<value >> optimized out>) at click.cc:639 >> >> One thing to note, for various reasons I'm doing something very >> unclick-like with FromDAG where I allow it to block up to 10ms. For my >> specific requirements this is not a problem, but just in case it might >> affect the way the new task handling operates it's worth noting. >> >> Beyers >> >> On Sun, Feb 6, 2011 at 1:23 AM, Eddie Kohler <[email protected]> wrote: >> >>> Hi all, >>> >>> This is just a note to say that I've merged the "coreperformance" branch >>> with master. There are several changes that may speed up particularly >>> simple configurations, and that (more importantly) may make it easier to >>> experiment with different multithreading setups. (For instance I >>> believe switching a task from one thread to another is faster now.) Let >>> me know if you experience any problems >>> >>> Eddie >>> _______________________________________________ >>> click mailing list >>> [email protected] >>> https://amsterdam.lcs.mit.edu/mailman/listinfo/click >>> >> >> > _______________________________________________ click mailing list [email protected] https://amsterdam.lcs.mit.edu/mailman/listinfo/click
