re: port-sparc/45255: GCC 4.5.3 and sparc re-triggers the NULL savefpstate IPI issue

[Hauke Fath <hauke%Espresso.Rhein-Neckar.DE@localhost>]

The following reply was made to PR port-sparc/45255; it has been noted by GNATS.

From: Hauke Fath <hauke%Espresso.Rhein-Neckar.DE@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: port-sparc-maintainer%NetBSD.org@localhost, 
gnats-admin%NetBSD.org@localhost,
        mrg%eterna.com.au@localhost
Subject: re: port-sparc/45255: GCC 4.5.3 and sparc re-triggers the NULL
 savefpstate IPI issue
Date: Wed, 17 Aug 2011 09:36:20 +0200

 At 18:10 Uhr +0000 15.8.2011, matthew green wrote:
 > > ...interesting. I have seen these NULL savefpstate panics on my ss20 (2x
 > > SM71) ever since I upgraded to HEAD. Just last weekend, I switched to a UP
 > > kernel to at least be able to build a few packages. Should have sent-pr
 > > earlier, I guess.
 >
 > hmmm, i haven't seen those panics for several months, not since i
 > made this change:
 >
 > revision 1.225
 > date: 2011/01/22 12:13:25;  author: mrg;  state: Exp;  lines: +3 -3
 > convert xpmsg_lock to IPL_SCHED.  the old spl/simple_lock code ran at
 > splsched(), and this significantly helps with stability under load
 > when running with multiple active CPUs.
 
 I've seen several reboots every day, and the machine wouldn't stay up long
 enough to build a non-trivial package, or make it through the nightly
 Amanda backup run.
 
 Since your change, I haven't seen a single kernel panic.
 
 > > Are you positive this is an exclusively gcc 4.5 related issue?
 >
 > not any more.  when it fails for you, can you get the backtraces
 > of both CPUs and post them?  thanks.
 
 I'll look into that next week.
 
        hauke
 
 --
 "It's never straight up and down"     (DEVO)