Re: QUESTION: Network hangs with BP6 and 2.4.x kernels, hardware related?

[Andrew Morton <andrewm@uow.edu.au>]

Frank de Lange wrote:
> 
> Quick and dirty conclusion: as soon as the apic comes in to play, things get
> messy...

Yup.

Frank, for over a year there have been sporadic reports
of APIC's forgetting how to deliver interrupts.  Not only
on BP6's.  Often with 3com NICs, so I've never been 100% sure
that it's not a failure in the NIC.

In your case, you have three devices on the same IRQ and
they all go to lunch at the same time.  That's pretty
convincing.

Nobody has been able to repeat this frequently enough
for any useful debugging to be done. Don't go away!

Here is a debugging patch.  Could you please apply this,
rebuild and:

1: Type ALT-SYSRQ-A when everything is good
2: Type ALT-SYSRQ-A when everything is bad
3: send the resulting logs.

I've Cc'ed Maciej, who understands this stuff.





--- linux-2.4.0-test11.macro/arch/i386/kernel/io_apic.c	Thu Oct  5 21:08:17 2000
+++ linux-2.4.0-test11/arch/i386/kernel/io_apic.c	Sun Nov 26 12:39:01 2000
@@ -692,7 +692,7 @@ void __init UNEXPECTED_IO_APIC(void)
 	printk(KERN_WARNING "          to linux-smp@vger.kernel.org\n");
 }
 
-void __init print_IO_APIC(void)
+void /*__init*/ print_IO_APIC(void)
 {
 	int apic, i;
 	struct IO_APIC_reg_00 reg_00;
diff -up --recursive --new-file linux-2.4.0-test11.macro/drivers/char/sysrq.c linux-2.4.0-test11/drivers/char/sysrq.c
--- linux-2.4.0-test11.macro/drivers/char/sysrq.c	Tue Nov 14 10:24:52 2000
+++ linux-2.4.0-test11/drivers/char/sysrq.c	Sun Nov 26 12:42:11 2000
@@ -72,6 +72,15 @@ void handle_sysrq(int key, struct pt_reg
 	console_loglevel = 7;
 	printk(KERN_INFO "SysRq: ");
 	switch (key) {
+	case 'a':
+		printk("\n");
+		printk("print_PIC()\n");
+		print_PIC();
+		printk("print_IO_APIC()\n");
+		print_IO_APIC();
+		printk("print_all_local_APICs()\n");
+		print_all_local_APICs();
+		break;
 	case 'r':					    /* R -- Reset raw mode */
 		if (kbd) {
 			kbd->kbdmode = VC_XLATE;
-
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