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Subject[RFC] NR_CPUS=8 on a 32 cpu box
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Andrew, All, 

So, I found the cause of that memory corruption I mentioned last night.
I was booting on the 16x w/ HT and I hadn't taken note that NR_CPUS now
defaults to 8. Whoops. Ends up there isn't any bounds checking when
bringing up the cpus, thus we overflow bios_cpu_apicid[].

Here's a quick patch that checks if num_processors has hit NR_CPUS.
Seems to fix it for me.

Let me know if you have any comments or suggestions.

thanks
-john

===== arch/i386/kernel/mpparse.c 1.49 vs edited =====
--- 1.49/arch/i386/kernel/mpparse.c Sun Aug 31 16:14:25 2003
+++ edited/arch/i386/kernel/mpparse.c Thu Sep 4 18:07:15 2003
@@ -167,6 +167,10 @@
boot_cpu_logical_apicid = apicid;
}

+ if (num_processors > NR_CPUS){
+ printk(KERN_WARNING "NR_CPUS limit of %i reached. Cannot boot CPU(apicid 0x%d).\n", NR_CPUS, m->mpc_apicid);
+ return;
+ }
num_processors++;

if (MAX_APICS - m->mpc_apicid <= 0) {


-
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