poll()/select()

[ray at redshift.com]

At 10:29 AM 11/21/2005 +0200, Konstantin Prokazoff wrote:
| Welcome everybody,
| 
|     have a strange issue under 5.x/6.x (checked).
|     When using a poll()/select() mechanism, which in kernel based on
| selrecord/selwakeup (pollscan, kern_select) functions, we have deadlock on
| sellock mutex on heavy load (recursive lock on non-recursive mutex). Have
| anyone seen this? Deadlock can be reached only if kernel w'be compiled with
| debugger, because in different case system locks, your can't login, etc.
| Maybe one path to resolve - change behavour of sched_lock & sellock mutexes
| block/unblock order.
|     Thnx in advance & for comments.
| 
| Best regards,
|         Konstantin Prokazoff
| Center Of Excellence, S_V_R Ltd., Kyiv HQs, Ukraine
| Official business-partner & DevConnect member of Avaya Inc.
| Regional development & support center of Digium Inc.
| Tel. +38 044 244 1181, ext. 1038
| Fax. +38 044 234 0455

The only thing I can add is that a sys admin friend of mine did try using the
poll/select to increase performance and had to finally abandon it due to
instability problems under load.

I've never tried it first hand myself.  Not sure if that helps you.

Ray