On 09/18/2010 02:36 PM, CAI Qian wrote:
>> Can you please apply the following patch, reproduce the problem and
>> report the kernel log?
> Tejun, which version this patch is against? Both 2.6.36-rc2-mm1 and 2.6.36-rc4-mm1 failed to apply it,
The patch was against percpu#for-next branch. Below is a patch
regenerated against the current linux-next.
Thanks.
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index bf43188..9510e7d 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -13,6 +13,7 @@
/* Stores the physical address of elf header of crash image. */
unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
+void per_cpu_ptr_to_phys_failed(void *addr);
/**
* copy_oldmem_page - copy one page from "oldmem"
* @pfn: page frame number to be copied
@@ -35,8 +36,10 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
return 0;
vaddr = ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
- if (!vaddr)
+ if (!vaddr) {
+ per_cpu_ptr_to_phys_failed(vaddr);
return -ENOMEM;
+ }
if (userbuf) {
if (copy_to_user(buf, vaddr + offset, csize)) {
diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c
index 7d9c1d0..357569a 100644
--- a/mm/percpu-vm.c
+++ b/mm/percpu-vm.c
@@ -415,6 +415,7 @@ static struct pcpu_chunk *pcpu_create_chunk(void)
{
struct pcpu_chunk *chunk;
struct vm_struct **vms;
+ int i;
chunk = pcpu_alloc_chunk();
if (!chunk)
@@ -429,6 +430,13 @@ static struct pcpu_chunk *pcpu_create_chunk(void)
chunk->data = vms;
chunk->base_addr = vms[0]->addr - pcpu_group_offsets[0];
+ chunk->chunkno = ++chunkno;
+ printk("XXX chunk %d allocated base_addr=%p\n",
+ chunk->chunkno, chunk->base_addr);
+ printk("XXX VMS:");
+ for (i = 0; i < pcpu_nr_groups; i++)
+ printk(" %zu@%p", vms[i]->size, vms[i]->addr);
+ printk("\n");
return chunk;
}
diff --git a/mm/percpu.c b/mm/percpu.c
index 77e3f5a..f4b094b 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -96,7 +96,10 @@
#define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr)
#endif /* CONFIG_SMP */
+static int chunkno;
+
struct pcpu_chunk {
+ int chunkno;
struct list_head list; /* linked to pcpu_slot lists */
int free_size; /* free bytes in the chunk */
int contig_hint; /* max contiguous size hint */
@@ -182,6 +185,40 @@ static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */
static void pcpu_reclaim(struct work_struct *work);
static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim);
+void pcpu_dump_chunk(struct pcpu_chunk *chunk)
+{
+ int i, contig = 0, free = 0;
+
+ printk("XXX %d(f=%d,c=%d,u=%d,a=%d)", chunk->chunkno,
+ chunk->free_size, chunk->contig_hint,
+ chunk->map_used, chunk->map_alloc);
+ for (i = 0; i < chunk->map_used; i++) {
+ if (chunk->map[i] > 0) {
+ free += chunk->map[i];
+ contig = max(contig, chunk->map[i]);
+ }
+ printk(" %d", chunk->map[i]);
+ }
+ printk(" free=%d contig=%d%s\n", free, contig,
+ (free != chunk->free_size || contig != chunk->contig_hint) ?
+ " MISMATCH!" : "");
+}
+
+void pcpu_dump_chunk_slots(void)
+{
+ struct pcpu_chunk *chunk;
+ int i;
+
+ printk("XXX percpu allocator dump\n");
+ for (i = 0; i < pcpu_nr_slots; i++) {
+ if (list_empty(&pcpu_slot[i]))
+ continue;
+ printk("XXX SLOT[%02d]\n", i);
+ list_for_each_entry(chunk, &pcpu_slot[i], list)
+ pcpu_dump_chunk(chunk);
+ }
+}
+
static bool pcpu_addr_in_first_chunk(void *addr)
{
void *first_start = pcpu_first_chunk->base_addr;
@@ -1021,6 +1058,19 @@ phys_addr_t per_cpu_ptr_to_phys(void *addr)
return page_to_phys(pcpu_addr_to_page(addr));
}
+void per_cpu_ptr_to_phys_failed(void *addr)
+{
+ phys_addr_t phys;
+ unsigned long flags;
+
+ phys = per_cpu_ptr_to_phys(addr);
+ printk("XXX per_cpu_ptry_to_phys(%p) returned invalid address 0x%llx\n",
+ addr, (unsigned long long)phys);
+ spin_lock_irqsave(&pcpu_lock, flags);
+ pcpu_dump_chunk_slots();
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+}
+
/**
* pcpu_alloc_alloc_info - allocate percpu allocation info
* @nr_groups: the number of groups
@@ -1283,6 +1333,11 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +
BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long);
+ printk("XXX CPU->UNIT M/O");
+ for_each_possible_cpu(cpu)
+ printk(" %d:%lx", unit_map[cpu], unit_off[cpu]);
+ printk("\n");
+
/*
* Allocate chunk slots. The additional last slot is for
* empty chunks.
@@ -1292,6 +1347,10 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
for (i = 0; i < pcpu_nr_slots; i++)
INIT_LIST_HEAD(&pcpu_slot[i]);
+ printk("XXX ss=%zu up=%d us=%d ns=%d rs=%zd ds=%zd\n",
+ ai->static_size, pcpu_unit_pages, pcpu_unit_size,
+ pcpu_nr_slots, ai->reserved_size, dyn_size);
+
/*
* Initialize static chunk. If reserved_size is zero, the
* static chunk covers static area + dynamic allocation area
@@ -1311,6 +1370,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
schunk->free_size = ai->reserved_size;
pcpu_reserved_chunk = schunk;
pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size;
+ schunk->chunkno = -1;
} else {
schunk->free_size = dyn_size;
dyn_size = 0; /* dynamic area covered */
@@ -1340,6 +1400,12 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
pcpu_first_chunk = dchunk ?: schunk;
pcpu_chunk_relocate(pcpu_first_chunk, -1);
+ if (pcpu_reserved_chunk) {
+ printk("XXX reserved chunk\n");
+ pcpu_dump_chunk(pcpu_reserved_chunk);
+ }
+ pcpu_dump_chunk_slots();
+
/* we're done */
pcpu_base_addr = base_addr;
return 0;
@@ -1623,6 +1689,7 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
goto out_free_areas;
}
areas[group] = ptr;
+ printk("XXX areas[%d]=%p\n", group, areas[group]);
base = min(ptr, base);
@@ -1639,12 +1706,15 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
}
/* base address is now known, determine group base offsets */
+ printk("XXX base_addr=%p", base);
max_distance = 0;
for (group = 0; group < ai->nr_groups; group++) {
ai->groups[group].base_offset = areas[group] - base;
max_distance = max_t(size_t, max_distance,
ai->groups[group].base_offset);
+ printk(" %lx", ai->groups[group].base_offset);
}
+ printk("\n");
max_distance += ai->unit_size;
/* warn if maximum distance is further than 75% of vmalloc space */
