fs.file-max

fs.file-max

[Federico Edelman Anaya]

Hi! ... In a Linux Kernel ...

What can I do to test the FD limit? ... Because, the FD limit is set in
/proc/sys/fs/file-max, sample:

echo "2048" > /proc/sys/fs/file-max
ulimit -n 8192

In this case ... the FD limit = 8192 :( ... when the limit should be
2048?

I wrote a perl script for the test ... anybody known a "C" program for
test the FD limit?


Thanks ...!

Re: fs.file-max

[Federico Edelman Anaya]

Dan:
    Hi ...

Dan Kegel wrote:

> Federico Edelman Anaya (fedelman@elsitio.com.ar) wrote:
>
> > What can I do to test the FD limit? ... Because, the FD limit is set in
> > /proc/sys/fs/file-max, sample:
> >
> > echo "2048" > /proc/sys/fs/file-max
>
> That sets the systemwide limit to 2048.

Ok ...

>
>
> > ulimit -n 8192
>
> That sets the per-process limit (for this process
> and its children) to 2048.
>

But, my perl script could open 8192 files ... I don't understand exactly
work ... which is the limit of FD? file-max?


>
> > In this case ... the FD limit = 8192 :( ... when the limit should be
> > 2048?
>
> No, the two limits are independant (except, obviously, that
> that process will reach the systemwide fd limit before it
> exhausts its per-process fd limit).
>
> > I wrote a perl script for the test ... anybody known a "C" program for
> > test the FD limit?
>
> http://www.kegel.com/dkftpbench/#tuning
>
> - Dan

Re: fs.file-max

[Dan Kegel]

Federico Edelman Anaya (fedelman@elsitio.com.ar) wrote:

> What can I do to test the FD limit? ... Because, the FD limit is set in 
> /proc/sys/fs/file-max, sample: 
> 
> echo "2048" > /proc/sys/fs/file-max 

That sets the systemwide limit to 2048.  

> ulimit -n 8192 

That sets the per-process limit (for this process
and its children) to 2048.  
 
> In this case ... the FD limit = 8192 :( ... when the limit should be 
> 2048? 

No, the two limits are independant (except, obviously, that
that process will reach the systemwide fd limit before it
exhausts its per-process fd limit).
 
> I wrote a perl script for the test ... anybody known a "C" program for 
> test the FD limit? 

http://www.kegel.com/dkftpbench/#tuning

- Dan

Re: fs.file-max

[Nathan Straz]

On Tue, May 08, 2001 at 10:03:23AM +0000, Federico Edelman Anaya wrote:
> What can I do to test the FD limit? ... Because, the FD limit is set in
> /proc/sys/fs/file-max, sample:
> 
> echo "2048" > /proc/sys/fs/file-max
> ulimit -n 8192
> 
> In this case ... the FD limit = 8192 :( ... when the limit should be
> 2048?
> 
> I wrote a perl script for the test ... anybody known a "C" program for
> test the FD limit?

Hmm, we seem to be missing this test case from the Linux Test Project.
I see that dup03 exhausts all FDs and tests dup() for EMFILE.  You could
easily adapt that test case to a setrlimit() test case.  

-- 
Nate Straz                                              nstraz@sgi.com
sgi, inc                                           http://www.sgi.com/
Linux Test Project                         http://ltp.sourceforge.net/