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Date:	Mon, 11 Feb 2002 13:48:38 +0200 (IST)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
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To:	djgpp AT delorie DOT com
Subject:	Re: Alignment problem
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On Mon, 11 Feb 2002, CBFalconer wrote:

> gcc 2.953.

I'm not sure -a is supported.  In fact, I'm not sure -a is supported in 
_any_ DJGPP port of any GCC version.

> Lots of time, see below.  At least until I can get a
> detailed look inside free.

Well, I'm not sure: the 1.17 second taken by `free' is only about 20 
clock ticks, so you are still pretty much on the clock granularity 
level.

> I suspect free is talking back to the dpmi memory manager.

You have the source, and it should show that `free' doesn't issue any 
system calls (because DJGPP programs never release any memory to the DPMI 
server).  So I think the calls to __dpmi_int are irrelevant to what 
`free' does, it's just that your program calls some system services 
elsewhere, and the profiling code catches some of these calls when it 
randomly probes the EIP at each clock tick.

I think if the main loop of your program, the one that allocates and 
frees objects, runs longer, the percent of time spent inside __dpmi_int 
will go down (assuming it's more-or-less constant overhead during program 
initialization and shut-down).

`free' calls 2 subroutines (`merge' and `b2bucket'), but they are both 
inlined.  I'd suggest to edit malloc.c, delete "inline" from these two 
functions' declarations, and then rebuild and rerun the test program 
again.  Perhaps that will show that one of them takes most of the time.

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