Re: WARNING: CPU: 1 PID: 495 at mm/slab_common.c:69 kmem_cache_create+0x1a9/0x330()

poma
2014-07-18T20:02:01Z

On 18.07.2014 16:17, Christoph Hellwig wrote:
> On Fri, Jul 18, 2014 at 05:21:04PM +0400, Vladimir Davydov wrote:
>> Slab warns, because the name of the cache being created contains spaces.
>> The "bad" cache is created by scsi_get_host_cmd_pool. Its name
>> (pool->cmd_name) is initialized by scsi_alloc_host_cmd_pool as follows:
>>
>> pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->name);
>>
>> So, if hostt->name contains spaces, the cache name will also contain
>> spaces and we'll get the warning. And hostt->name can contain spaces,
>> e.g. virtscsi_host_template_single.name="Virtio SCSI HBA".
>
> Or might not even be present. I'll send a patch to replace it with
> ->proc_name, which must not contain spaces and is generally shorter
> as well.
>

Is this what you thought?
@@ -148,20 +148,20 @@
struct kmem_cache *cmd_slab;
struct kmem_cache *sense_slab;
unsigned int users;
- char *cmd_name;
+ char *proc_name;
char *sense_name;
unsigned int slab_flags;
gfp_t gfp_mask;
};

static struct scsi_host_cmd_pool scsi_cmd_pool = {
- .cmd_name = "scsi_cmd_cache",
+ .proc_name = "scsi_cmd_cache",
.sense_name = "scsi_sense_cache",
.slab_flags = SLAB_HWCACHE_ALIGN,
};

static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
- .cmd_name = "scsi_cmd_cache(DMA)",
+ .proc_name = "scsi_cmd_cache(DMA)",
.sense_name = "scsi_sense_cache(DMA)",
.slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
.gfp_mask = __GFP_DMA,
@@ -354,7 +354,7 @@
scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool)
{
kfree(pool->sense_name);
- kfree(pool->cmd_name);
+ kfree(pool->proc_name);
kfree(pool);
}

@@ -368,9 +368,9 @@
if (!pool)
return NULL;

- pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->name);
+ pool->proc_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->name);
pool->sense_name = kasprintf(GFP_KERNEL, "%s_sense", hostt->name);
- if (!pool->cmd_name || !pool->sense_name) {
+ if (!pool->proc_name || !pool->sense_name) {
scsi_free_host_cmd_pool(pool);
return NULL;
}
@@ -403,7 +403,7 @@
}

if (!pool->users) {
- pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0,
+ pool->cmd_slab = kmem_cache_create(pool->proc_name, cmd_size, 0,
pool->slab_flags, NULL);
if (!pool->cmd_slab)
goto out_free_pool;

however ain't workin.

poma