Hello, Greg
I'm not sure if I complete follow your explanation. So if I have the
following block of code, where would you put ProfilerStart and ProfilerStop
?
var arrayA: [1..numMessages] real;
forall msg in 1..numMessages do {
arrayA[msg] = 0.1;
for i in 1..100000 {
CPUheavy(arrayA[msg]);
CPUlight(arrayA[msg]);
}
writeln("Hello, world! (from iteration ", msg, " of ",
numMessages, ") has
arrayA[msg] ",arrayA[msg]);
}
the thread creating calls should appear within the red line, but if I want
to see which function is spending most time among all the threads, then
shall I put ProfStart and ProfStop outside or inside the red line ?
Thanks
On Tue, Oct 20, 2015 at 6:26 PM, Greg Titus <[email protected]> wrote:
> I haven't had trouble with it crashing. This might be because I always
> put the start/stop calls in serial code, before or after any parallel
> constructs but not within them. Since parallel constructs other than
> begin-stmts have implicit syncs afterward, and all the runtime tasking
> layers only create threads (if they have to at all) in order to execute
> parallel constructs, this means that the start/stop calls and the thread
> creation calls are well separated.
>
> That's just a hypothesis, but personally I don't recall having any
> trouble with gperftools crashing.
>
>
> greg
>
>
> On Tue, 20 Oct 2015, Hui Zhang wrote:
>
> Ah... sorry I missed that.
>> It works now , thanks !
>>
>> One more question: from gperftools' README, it seems like it sometimes
>> crashes when threads get created, and it suggested to avoid putting
>> ProfilerStart and ProfilerStop among the places where new threads get
>> forked, but in this way, how can I profile the multi-threading feature in
>> Chapel ? How did you normally use it to profile a Chapel code with
>> forall/coforall clauses ?
>>
>> Thanks !
>>
>> On Tue, Oct 20, 2015 at 6:06 PM, Greg Titus <[email protected]> wrote:
>> I think it's complaining about ProfilerStop(), perhaps that
>> you need:
>> void ProfilerStop(void);
>>
>> to make it a complete prototype by saying explicitly that it
>> takes no
>> arguments?
>>
>> greg
>>
>>
>> On Tue, 20 Oct 2015, Hui Zhang wrote:
>>
>> Hello, Greg
>>
>> So I create a prof-decls.h and put these two
>> lines in it:
>> int ProfilerStart(const char* fname);
>> void ProfilerStop();
>> which I get from the gperftools/profiler.h
>> chpl -g myCode.chpl prof-decls.h -I../include/ -o
>> myCode -L../lib -ltest
>> it reports less errors but still this one:
>>
>> In file included from /chpl__header.h:5:0,
>> from /_main.c:1:
>> ./prof-decls.h:2:1: error: function
>> declaration isn’t a
>> prototype [-Werror=strict-
>> prototypes]
>>
>> why the ProfilerStart declaration isn't the
>> function prototype ?
>> Thanks
>>
>>
>> On Tue, Oct 20, 2015 at 5:07 PM, Greg Titus
>> <[email protected]> wrote:
>> Hello --
>>
>> I believe you can solve this problem by
>> putting C-style
>> declarations for
>> ProfilerStart() and ProfilerStop() in a .h
>> file
>> (prof-decls.h, say) and
>> then adding that .h file to the chpl
>> command line:
>>
>> chpl -g myCode.chpl prof-decls.h
>> -I../include/ -o myCode
>> -L../lib -ltest
>>
>> (Sorry I didn't yet respond to your earlier
>> message. I
>> needed time to
>> dig into the cause of the problem, but had
>> not found that
>> time yet.)
>>
>> greg
>>
>>
>> On Tue, 20 Oct 2015, Hui Zhang wrote:
>>
>> Hello,
>>
>> I'm trying to use gperftools to
>> profile the
>> Chapel code, but simply link
>> the profiler library doesn't produce
>> the profile
>> file, so I need to
>> explicitly call two external C
>> functions within
>> my Chapel code, here's
>> what I did:
>>
>> 1. in my chapel module:
>> extern proc
>> ProfilerStart(name:
>> c_string);
>> **it suggested me to use
>> c_string
>> instead of string
>> exetern proc ProfilerStop();
>> then in proc main, I called this
>> two
>> functions
>> 2. recompile my chapel program:
>> chpl -g myCode.chpl
>> -I../include/ -o
>> myCode -L../lib -ltest
>>
>> But I got this error :
>> /_main.c:30:0:
>> /Hui.c: In function ‘chpl_user_main’:
>> /Hui.c:160:1: error: implicit
>> declaration of
>> function ‘ProfilerStart’
>>
>> [-Werror=implicit-function-declaration]
>> /Hui.c:160:1: error: nested extern
>> declaration of
>> ‘ProfilerStart’
>> [-Werror=nested-externs]
>> /Hui.c:163:1: error: implicit
>> declaration of
>> function ‘ProfilerStop’
>>
>> [-Werror=implicit-function-declaration]
>> /Hui.c:163:1: error: nested extern
>> declaration of
>> ‘ProfilerStop’
>> [-Werror=nested-externs]
>> cc1: all warnings being treated as
>> errors
>> make: ***
>>
>> [/tmp/chpl-hzhang86-15966.deleteme/experiment.work.funh.tmp]
>> Error 1
>> error: compiling generated source
>> [mysystem.cpp:43]
>>
>> Should I just ignore these warnings ?
>> but how to
>> disable this warning as
>> error option?
>> Or am I doing it wrong ?
>>
>> Thanks
>>
>> --
>> Best regards
>>
>>
>> Hui Zhang
>>
>>
>>
>>
>> --
>> Best regards
>>
>>
>> Hui Zhang
>>
>>
>>
>>
>> --
>> Best regards
>>
>>
>> Hui Zhang
>>
>>
--
Best regards
Hui Zhang
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