Re: checking for epoll / compiling kernel

[Cole S. Ashcraft]

Sam Watkins wrote:
On Wed, Nov 24, 2004 at 08:01:22AM -0800, Cole S. Ashcraft wrote:
 

1: Is there a way to check to see if I have epoll support (the epoll.h 
library exists, using sid and a 2.4.18 kernel)
   

from the epoll manpage:
 

epoll(4) is a new API introduced in Linux kernel 2.5.44.  Its interface
should be finalized in Linux kernel 2.5.66.
   

I have a different man page:
    epoll  is a variant of poll(2) that can be used either as Edge or Level
      Triggered interface and scales well to large numbers  of  
watched  fds.
      Three  system  calls  are  provided to set up and control an 
epoll set:
      epoll_create(2), epoll_ctl(2), epoll_wait(2).
Is it the same epoll?

When i locate epoll (using locate), I get:
/usr/include/sys/epoll.h
/usr/share/man/man2/epoll_create.2.gz
/usr/share/man/man2/epoll_ctl.2.gz
/usr/share/man/man2/epoll_wait.2.gz
/usr/share/man/man4/epoll.4.gz
The results of locate on my Cobalt (the one using 2.4.18) are no 
different from the result on my 2.6.9 box (FC2)... hmm. I've also heard 
it said that libc implements epoll. Is that correct?

so 2.4.18 doesn't come with epoll support - apparently you'll need a 2.6 
kernel
for this.  There's a patch for 2.4 at:
 http://www.xmailserver.org/linux-patches/nio-improve.html#patches
 

Is /dev/epoll different than epoll? My 2.6.9 system does not have a 
/dev/epoll device, but I know it has epoll support.

or maybe you mean how to check if the system has epoll support,
in a configure script?  as for that, write a little test program that
tries to use it I guess.
 

2: Can I compile a kernel on another machine? I'd like to use my fast 
machine to comile a kernel for my slow cobalt, but can I do this?
   

Yes.  You just need to choose an appropriate processor type in the kernel
config.  For the x86 architecture, 386 is a safe bet!
What's a "cobalt"?
 

Cobalt is a "thin blue server" appliance made by Sun a long time ago. I 
hated the Cobalt OS (also a linux, 2.2 kernel) so I put Debian on it. 
Now I'm trying to push the limits again and run Lotus Domino, which 
requires epoll.

Sam
 


--
To UNSUBSCRIBE, email to [EMAIL PROTECTED] 
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]