Messages in this thread |  | | Date | Wed, 19 Sep 2001 15:11:47 -0700 (PDT) | From | Davide Libenzi <> | Subject | Re: [PATCH] /dev/epoll update ... |
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On 19-Sep-2001 Christopher K. St. John wrote: > Davide Libenzi wrote: >> >> > - check new_socket_fd for readable, writable, and >> > error. if any true, then add new event to >> > event queue, as if the state had changed. >> >> No it does't check. It's not needed for how it works. >> > > Yes, I see that it currently works that way. I'm > suggesting that it's a needlessly awkward way to work. > It also results in thousands of spurious syscalls a > second as servers are forced to double check there > isn't i/o to be done.
Again :
1) select()/poll(); 2) recv()/send();
vs :
1) if (recv()/send() == FAIL) 2) ioctl(EP_POLL);
When there's no data/tx buffer full these will result in 2 syscalls while if data is available/tx buffer ok the first method will result in 2 syscalls while the second will never call the ioctl(). It looks very linear to me, with select()/poll() you're asking for a state while with /dev/epoll you're asking for a state change.
- Davide
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