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From: Robert Watson <rwatson@FreeBSD.org>
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To: Divacky Roman <xdivac02@stud.fit.vutbr.cz>
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Cc: freebsd-current@freebsd.org, Giorgos Keramidas <keramida@freebsd.org>,
	Kris Kennaway <kris@obsecurity.org>
Subject: Re: [PATCH]: fdalloc optimization
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On Mon, 22 Aug 2005, Divacky Roman wrote:

>> By running an application that opens (and keeps open) many files, i.e. 
>> a program that creates many temporary files, keeps them open and then 
>> closes them all at once before exiting?
>
> I did:
>
> gettimeofday(&t1, NULL);
>   for (; i>0; i--) {
>            if (open("/dev/null", O_RDONLY) == -1) {
> 		perror(NULL);
> 		break;
> 	    }
>  }
> gettimeofday(&t2, NULL);

src/tools/tools/syscall_timing provides a number of simple 
micro-benchmarks of common system calls, including several that allocate 
file descriptors (such as pipe creation, socket allocation, etc).  Run 
about ten sets each of {before,after}, drop the first entry for each 
("warmup"), and then use ministat to compare the results on a couple of 
key system calls?

Robert N M Watson