On 11/19/2017 08:08 PM, Nicolas Pitre wrote:
On Sun, 19 Nov 2017, Guenter Roeck wrote:
On 11/19/2017 12:36 PM, Nicolas Pitre wrote:
On Sat, 18 Nov 2017, Guenter Roeck wrote:
On Tue, Oct 03, 2017 at 06:29:49PM -0400, Nicolas Pitre wrote:
@@ -2295,6 +2295,7 @@ void __init setup_per_cpu_areas(void)
if (pcpu_setup_first_chunk(ai, fc) < 0)
panic("Failed to initialize percpu areas.");
+ pcpu_free_alloc_info(ai);
This is the culprit. Everything works fine if I remove this line.
Without this line, the memory at the ai pointer is leaked. Maybe this is
modifying the memory allocation pattern and that triggers a bug later on
in your case.
At that point the console driver is not yet initialized and any error
message won't be printed. You should enable the early console mechanism
in your kernel (see arch/cris/arch-v32/kernel/debugport.c) and see what
that might tell you.
The problem is that BUG() on crisv32 does not yield useful output.
Anyway, here is the culprit.
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 6aef64254203..2bcc8901450c 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -382,7 +382,8 @@ static int __init mark_bootmem(unsigned long start,
unsigned long end,
return 0;
pos = bdata->node_low_pfn;
}
- BUG();
+ WARN(1, "mark_bootmem(): memory range 0x%lx-0x%lx not found\n", start,
end);
+ return -ENOMEM;
}
/**
diff --git a/mm/percpu.c b/mm/percpu.c
index 79e3549cab0f..c75622d844f1 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1881,6 +1881,7 @@ struct pcpu_alloc_info * __init
pcpu_alloc_alloc_info(int nr_groups,
*/
void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai)
{
+ printk("pcpu_free_alloc_info(%p (0x%lx))\n", ai, __pa(ai));
memblock_free_early(__pa(ai), ai->__ai_size);
The problem here is that there is two possibilities for
memblock_free_early(). From include/linux/bootmem.h:
#if defined(CONFIG_HAVE_MEMBLOCK) && defined(CONFIG_NO_BOOTMEM)
static inline void __init memblock_free_early(
phys_addr_t base, phys_addr_t size)
{
__memblock_free_early(base, size);
}
#else
static inline void __init memblock_free_early(
phys_addr_t base, phys_addr_t size)
{
free_bootmem(base, size);
}
#endif
It looks like most architectures use the memblock variant, including all
the ones I have access to.
results in:
pcpu_free_alloc_info(c0534000 (0x40534000))
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at mm/bootmem.c:385 mark_bootmem+0x9a/0xaa
mark_bootmem(): memory range 0x2029a-0x2029b not found
Well... PFN_UP(0x40534000) should give 0x40534. How you might end up
with 0x2029a in mark_bootmem(), let alone not exit on the first "if (max
== end) return 0;" within the loop is rather weird.
pcpu_free_alloc_info: ai=c0536000, __pa(ai)=0x40536000, PFN_UP(__pa(ai))=0x2029b, PFN_UP(ai)=0x6029b
bootmem range is 0x60000..0x61000. It doesn't get to "if (max == end)"
because "pos (=0x2029b) < bdata->node_min_pfn (=0x60000)".
Guenter
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