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authorTejun Heo <tj@kernel.org>2009-09-24 09:43:11 +0900
committerTejun Heo <tj@kernel.org>2009-09-29 09:17:57 +0900
commit635b75fc18858d3522e481c043de764766db923c (patch)
tree0bd2dc916bac8d0188bdd3ba15d0a1b00aa86e48 /mm/percpu.c
parent6ea529a2037ce662fc6bfa572b46d47407d08805 (diff)
downloadvexpress-lsk-635b75fc18858d3522e481c043de764766db923c.tar.gz
percpu: make pcpu_setup_first_chunk() failures more verbose
The parameters to pcpu_setup_first_chunk() come from different sources depending on architecture and can be quite complex. The function runs various sanity checks on the parameters and triggers BUG() if something isn't right. However, this is very early during the boot and not reporting exactly what the problem is makes debugging even harder. Add PCPU_SETUP_BUG() macro which prints out enough information about the parameters. As the macro still puts separate BUG() for each check, it won't lose any information even on the situations where only the program counter can be retrieved. While at it, also bump pcpu_dump_alloc_info() message to KERN_INFO so that it's visible on the console if boot fails to complete. Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'mm/percpu.c')
-rw-r--r--mm/percpu.c37
1 files changed, 26 insertions, 11 deletions
diff --git a/mm/percpu.c b/mm/percpu.c
index c43da8c024d..83617ca3ba5 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1578,6 +1578,7 @@ static void pcpu_dump_alloc_info(const char *lvl,
int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
void *base_addr)
{
+ static char cpus_buf[4096] __initdata;
static int smap[2], dmap[2];
size_t dyn_size = ai->dyn_size;
size_t size_sum = ai->static_size + ai->reserved_size + dyn_size;
@@ -1589,17 +1590,26 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
int *unit_map;
int group, unit, i;
+ cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask);
+
+#define PCPU_SETUP_BUG_ON(cond) do { \
+ if (unlikely(cond)) { \
+ pr_emerg("PERCPU: failed to initialize, %s", #cond); \
+ pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \
+ pcpu_dump_alloc_info(KERN_EMERG, ai); \
+ BUG(); \
+ } \
+} while (0)
+
/* sanity checks */
BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC ||
ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC);
- BUG_ON(ai->nr_groups <= 0);
- BUG_ON(!ai->static_size);
- BUG_ON(!base_addr);
- BUG_ON(ai->unit_size < size_sum);
- BUG_ON(ai->unit_size & ~PAGE_MASK);
- BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);
-
- pcpu_dump_alloc_info(KERN_DEBUG, ai);
+ PCPU_SETUP_BUG_ON(ai->nr_groups <= 0);
+ PCPU_SETUP_BUG_ON(!ai->static_size);
+ PCPU_SETUP_BUG_ON(!base_addr);
+ PCPU_SETUP_BUG_ON(ai->unit_size < size_sum);
+ PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK);
+ PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);
/* process group information and build config tables accordingly */
group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0]));
@@ -1622,8 +1632,9 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
if (cpu == NR_CPUS)
continue;
- BUG_ON(cpu > nr_cpu_ids || !cpu_possible(cpu));
- BUG_ON(unit_map[cpu] != UINT_MAX);
+ PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids);
+ PCPU_SETUP_BUG_ON(!cpu_possible(cpu));
+ PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX);
unit_map[cpu] = unit + i;
unit_off[cpu] = gi->base_offset + i * ai->unit_size;
@@ -1636,7 +1647,11 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
pcpu_nr_units = unit;
for_each_possible_cpu(cpu)
- BUG_ON(unit_map[cpu] == UINT_MAX);
+ PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX);
+
+ /* we're done parsing the input, undefine BUG macro and dump config */
+#undef PCPU_SETUP_BUG_ON
+ pcpu_dump_alloc_info(KERN_INFO, ai);
pcpu_nr_groups = ai->nr_groups;
pcpu_group_offsets = group_offsets;