Re: cvs commit: src/sys/kern sched_ule.c (fwd)

Jeff Roberson wrote:
> On Tue, 14 Dec 2004, Scott Long wrote:
> 
> 
>>Jon Noack wrote:
>>
>>>Tony Arcieri wrote:
>>>
>>>
>>>>On Tue, Dec 14, 2004 at 05:08:43PM -0600, Jon Noack wrote:
>>>>
>>>>
>>>>>I thought about trying this last night when I saw that ULE was
>>>>>resurrected.  Make sure you also grab kern_sig.c:
>>>>>http://lists.freebsd.org/pipermail/cvs-src/2004-December/036757.html
>>>>>
>>>>>I can't say whether those 3 files are all you need, just that I would
>>>>>also include kern_sig.c... ;-)
>>>>
>>>>Rebuilt with kern_sig.c from -CURRENT, everything seems fine, as far as I
>>>>can tell.  Are there really any substantial changes in kern_sig.c and
>>>>kern_switch.c that would affect the stability of 5_STABLE (and does
>>>>UMA in 5_STABLE ensure thati proc_fini() won't be called?)
>>>
>>>
>>>I don't know about kern_switch.c, but the change in kern_sig.c fixes #2 on
>>>Jeff Roberson's list of bugs in ULE (from a few days ago):
>>>http://lists.freebsd.org/pipermail/freebsd-current/2004-December/044332.html
>>>
>>>
>>>
>>>>I'd just contend that in the case of my system, 5_STABLE with the 4BSD
>>>>scheduler is not stable, or at least the script I'm running is somehow
>>>>exhausting system resources to the point that the system becomes unusable,
>>>>and this problem isn't exhibited with the ULE scheduler.  Regardless, the
>>>>script was causing the 5.3-RELEASE GENERIC kernel to panic, and rendered
>>>>the system completely inaccessible with a kernel built from the latest (as
>>>>of about 5 days ago) RELENG_5 kernel with the 4BSD scheduler.
>>>>
>>>>So, I'd be very grateful if ULE could be merged into RELENG_5 as it would
>>>>dramatically improve the stability of at least my server.  Has anyone else
>>>>with a dual amd64 system had problems like this post 5.3-RELEASE?  I know
>>>>crashes under heavy MySQL load on dual amd64 systems were a problem
>>>>before, but I thought that had been resolved.
>>>
>>>
>>>I think removing the #error and putting a note on boot (and in UPDATING)
>>>that it may still be unstable is a good idea.  However, Scott Long has
>>>expressed reservations
>>>(http://lists.freebsd.org/pipermail/freebsd-current/2004-December/044341.html)
>>>and his opinion counts orders of magnitude more than mine.
>>>
>>>Jon
>>>
>>
>>I'm definitely not against these fixes going into RELENG_5, but I would
>>like to see some significant testing be applied to them in HEAD first,
>>especially to changes that are not confined to just sched_ule.c (and
>>sched_4bsd.c).
> 
> 
> Can I commit changes that are restricted to sched_ule.c?  It certainly
> can't make things any worse than they are on RELENG_5 now.  We can leave
> the #error in until it's really tested on head.  That way only people who
> remove that line of code can use it.
> 

Sounds like a good plan.

Scott