Date: Thu, 22 Feb 2001 06:18:16 -0800 (PST) From: John Baldwin <jhb@FreeBSD.org> To: Maxim Sobolev <sobomax@FreeBSD.org> Cc: "Alexander N. Kabaev" <ak03@gte.com>, current@FreeBSD.org, Dag-Erling Smorgrav <des@ofug.org> Subject: Re: A possible bug in the interrupt thread preemption code [Was: Message-ID: <XFMail.010222061816.jhb@FreeBSD.org> In-Reply-To: <3A951A25.953E2988@FreeBSD.org>
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On 22-Feb-01 Maxim Sobolev wrote: >> > Here it is (from DDB): >> > panic(c027de93,c0297409,c027f878,368,80286) >> > _mtx_assert(c02ea000,9,c027f878,368,80286) >> > mi_switch(c32c5da0,3,c02cea44,c357be98) >> > ithread_schedule(c0747c00,1) >> > sched_ithd(e) >> > Xresume14() >> > --- interrupt, eip = 0xc025b60f, esp = 0x80296, ebp = 0xc357bf08 --- >> > trap(18, 10, 10,c01597b6,20) >> > calltrap() >> > --- trap 0x9, eip = 0xc025a5de, esp = 0xc357bf50, ebp = 0xc357bf64 --- >> > sw1b(c0146cbc,c0146cbc,c32c5da0,c357bf94) >> > ithread_loop(c0747c00,c357bfa8) >> > fork_exit(c0146cbc,c0747c00,c357bfa8) >> > fork_trampoline() >> >> *sigh* This is why enabling interrupts in trap() is such a bad idea. If we >> get a trap in the scheduler, then lots of bad crap starts to happen because >> we >> can get an interrupt while we are in a trap. :( Can you compile your kernel >> with >> INVARIANTS on though, as I think the kernel should've panic'd earlier if it >> is >> doing what I think it is doing. > > It's already have INVARIANTS, MUTEX_DEBUG, WITNESS and WITNESS_DDB. Hmm, ouch, you do'nt want MUTEX_DEBUG, that'll slow your system to a crawl. >> Also, if you are feeling industrious, edit >> sys/i386/i386/trap.c and comment out the enable_intr() call near the >> beginning >> of the trap() function right after the printf for 'kernel trap %d with >> interrupts disabled'. > > Ok, I'll try so. > > -Maxim It will still panic, just hopefully a better panic. -- John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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