kern/61691: very bad performance of realloc()/brk()

[Poul-Henning Kamp]

In message <20040123152035.GA2311 at asura.bsd>, Radim Kolar writes:
>> You seem to be confused as to what responsibilities the programmer
>> has when it comes to practicing sensible memory management.
>I have run some benchmarks for you. There are doing 32 times realloc() in
>1 MB chunks. I don't think that this is example of bad programming
>practice. The major problem is that realloc() copies data while Linux
>doesn't.

No, as I said, the problem is you use realloc the wrong way.

You should not

	malloc(1M)
	realloc(2M)
	realloc(3M)

You should

	realloc(32M)
	do stuff
	realloc(now_i_know_the_size)

For whatever value of 32M 99% of your data fit in.
	

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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