From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bpointsys.com (70-253-197-251.ded.swbell.net [70.253.197.251]) by ozlabs.org (Postfix) with ESMTP id 28E0867A3E for ; Sat, 12 Aug 2006 00:50:46 +1000 (EST) From: Brent Cook To: linuxppc-embedded@ozlabs.org Subject: Re: Realtime preemption patch on PPC Date: Fri, 11 Aug 2006 09:38:45 -0500 References: <1155251072.5950.80.camel@localhost> In-Reply-To: <1155251072.5950.80.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200608110938.45385.bcook@bpointsys.com> List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thursday 10 August 2006 18:04, Ben Weintraub wrote: > Howdy, > > I'm wondering if anyone has had success getting Ingo Molnar's realtime > preemption patch (the one here: > http://people.redhat.com/mingo/realtime-preempt/ ) working on the ppc > arch. I have gotten them to work with MPC7448 boards, but it has hardware floating point, so no math-emu problems. > Anyhow, when I boot on an MPC8555 with my hack, I get an endless stream > of: > > BUG: sleeping function called from invalid context init(1) at > arch/powerpc/math-emu/math.c:226 > in_atomic():0 [00000000], irqs_disabled():1 > Call Trace: > [A0BB3E90] [A000934C] show_stack+0x48/0x194 (unreliable) > [A0BB3EC0] [A001B7DC] __might_sleep+0xe8/0xf4 > [A0BB3EE0] [A00136C0] do_mathemu+0x30/0x8c8 > [A0BB3F00] [A00036AC] program_check_exception+0x1ac/0x514 > [A0BB3F40] [A0002A08] ret_from_except_full+0x0/0x4c > > Line 226 in arch/powerpc/math-emu/math.c is part of the do_mathemu() > function, and contains a call to get_user(), which calls > __might_sleep(), causing this problem. >