[PATCH 1/1] x86: leave initial __cpu_pda array in place until cpusare booted

From: Mike Travis
Date: Wed Apr 30 2008 - 11:02:51 EST


Ingo Molnar wrote:
...
> they crashed after about 3 randconfig iterations with:
>
> early res: 4 [8000-afff] PGTABLE
> early res: 5 [b000-b87f] MEMNODEMAP
> PANIC: early exception 0e rip 10:ffffffff8077a150 error 2 cr2 37
> Pid: 0, comm: swapper Not tainted 2.6.25-sched-devel.git-x86-latest.git #14
>
> Call Trace:
> [<ffffffff81466196>] early_idt_handler+0x56/0x6a
> [<ffffffff8077a150>] ? numa_set_node+0x30/0x60
> [<ffffffff8077a129>] ? numa_set_node+0x9/0x60
> [<ffffffff8147a543>] numa_init_array+0x93/0xf0
> [<ffffffff8147b039>] acpi_scan_nodes+0x3b9/0x3f0
> [<ffffffff8147a496>] numa_initmem_init+0x136/0x150
> [<ffffffff8146da5f>] setup_arch+0x48f/0x700
> [<ffffffff802566ea>] ? clockevents_register_notifier+0x3a/0x50
> [<ffffffff81466a87>] start_kernel+0xd7/0x440
> [<ffffffff81466422>] x86_64_start_kernel+0x222/0x280
...
Here's the fixup... This one should follow the previous patches.

Thanks,
Mike
---
Subject: [PATCH 1/1] x86: leave initial __cpu_pda array in place until cpus are booted

* The __cpu_pda table must be a set of NULL entries (except for the boot cpu)
to indicate to numa_set_node during early system initialization that the
cpu pdas are not yet setup. The pda nodenumber is set later in pda_init().

Based on:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
+ sched-devel/latest .../mingo/linux-2.6-sched-devel.git


Signed-off-by: Mike Travis <travis@xxxxxxx>
---
arch/x86/kernel/head64.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

--- linux-2.6.sched.orig/arch/x86/kernel/head64.c
+++ linux-2.6.sched/arch/x86/kernel/head64.c
@@ -29,17 +29,13 @@
static struct x8664_pda _boot_cpu_pda __read_mostly;

#ifdef CONFIG_SMP
-#ifdef CONFIG_DEBUG_PER_CPU_MAPS
/*
- * We install an empty cpu_pda pointer table to trap references before
- * the actual cpu_pda pointer table is created in setup_cpu_pda_map().
+ * We install an empty cpu_pda pointer table to indicate to early users
+ * (numa_set_node) that the cpu_pda pointer table for cpus other than
+ * the boot cpu is not yet setup.
*/
static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata;
#else
-static struct x8664_pda *__cpu_pda[1] __read_mostly;
-#endif
-
-#else /* !CONFIG_SMP (NR_CPUS will be 1) */
static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly;
#endif

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