[openib-general] add SIGUSR1 to reopen osm.log

[Sasha Khapyorsky]

On 13:43 Mon 20 Nov     , Hal Rosenstock wrote:
> On Thu, 2006-11-16 at 20:53, Ira Weiny wrote:
> > Our sysadmins have been rotating OpenSM's osm.log file and then restarting
> > OpenSM.  As this is a less than optimal solution if you have jobs running on
> > the system, I wrote this patch (against OFED 1.1) which adds a handler for
> > SIGUSR1 that reopens OpenSM's log file without a restart.
> 
> This is a good idea to incorporate into OpenSM.
> 
> Any objections if this is bundled with SIGHUP handling rather than
> SIGUSR1 which is not backward compatible as Sasha indicated ?

Actually looking more at this I noticed that SIGUSR* signals are not
used anymore with linuxthread couple of years (since kernel 2.1.xx,
where RT signals support was introduced). So I think it is not real
issue today - some #ifdef should be sufficient.

I reviewed and tested the original patch (it is appliable very well) and
have some fixes/improvements. Two incremental patches are followng.

Sasha