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Cc: OCaml <caml-list@inria.fr>
Message-Id: <5043CED0-7CEC-4813-8325-76C3196E8FEE@gmail.com>
From: Warren Harris <warrensomebody@gmail.com>
To: Richard Jones <rich@annexia.org>
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Subject: Re: [Caml-list] gc overhead
Date: Tue, 2 Mar 2010 12:11:11 -0800
References: <37150F07-8902-464A-9A0E-44A0C424C87B@gmail.com> <20100301085430.GA16106@annexia.org>
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On Mar 1, 2010, at 12:54 AM, Richard Jones wrote:

> On Sun, Feb 28, 2010 at 04:16:03PM -0800, Warren Harris wrote:
>> I would like to determine what percentage of my application's cpu  
>> time
>> is spent in the garbage collector (for tuning purposes, but also just
>> to monitor the overhead). Is there any way to obtain this information
>> short of using gprof? Additional information provided by Gc.stat  
>> would
>> be ideal, or perhaps a Gc.alarm that was called at the beginning of
>> the gc cycle, but neither of these seem to exist.
>
> I would have to say what's wrong with using gprof?

What's wrong with it is that it provides no way to monitor gc overhead  
in an active service.

>
> On a related topic: Has anyone tried using SystemTap with userspace
> DTrace-compatible probes to measure anything about total kernel +
> userspace usage of OCaml programs?  ie, this sort of thing:
>
> http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps
>
> but with OCaml programs.
>
> Rich.
>
> -- 
> Richard Jones
> Red Hat