Messages in this thread | | | Date | Tue, 24 Jun 2008 12:24:01 +0200 | From | Ingo Molnar <> | Subject | [bug] Re: [PATCH] - Fix stack overflow for large values of MAX_APICS |
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* Ingo Molnar <mingo@elte.hu> wrote:
> * Jack Steiner <steiner@sgi.com> wrote: > > > physid_mask_of_physid() causes a huge stack (12k) to be created if > > the number of APICS is large. Replace physid_mask_of_physid() with a > > new function that does not create large stacks. This is a problem > > only on large x86_64 systems. > > this indeed fixes the crash i reported here: > > http://lkml.org/lkml/2008/6/19/98 > > so i've added both this and the MAXAPICS patch to tip/x86/uv, and will > test it some more. Lets hope it goes all well this time :-)
-tip auto-testing found a new boot failure on x86 which happens if NR_CPUS is changed from 8 to 4096. The hang goes like this:
Linux version 2.6.26-rc7-tip (mingo@dione) (gcc version 4.2.3) #10233 SMP Tue Jun 24 12:13:46 CEST 2008 [...] initcall init_mnt_writers+0x0/0x8c returned 0 after 0 msecs calling eventpoll_init+0x0/0x9a initcall eventpoll_init+0x0/0x9a returned 0 after 0 msecs calling anon_inode_init+0x0/0x11a initcall anon_inode_init+0x0/0x11a returned 0 after 0 msecs calling pcie_aspm_init+0x0/0x27 initcall pcie_aspm_init+0x0/0x27 returned 0 after 0 msecs calling acpi_event_init+0x0/0x57 [... hard hang ...]
on a good bootup, it would continue like this:
initcall acpi_event_init+0x0/0x57 returned 0 after 38 msecs calling pnp_system_init+0x0/0x17 [...]
the config, full bootlog and reproducer bzImage is at:
http://redhat.com/~mingo/misc/config-Tue_Jun_24_07_44_17_CEST_2008.bad http://redhat.com/~mingo/misc/log-Tue_Jun_24_07_44_17_CEST_2008.bad http://redhat.com/~mingo/misc/bzImage-Tue_Jun_24_07_44_17_CEST_2008.bad
changing CONFIG_NR_CPUS from 4096 to 8 causes the system to boot up fine.
Ingo
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