diff mbox

[4/4] rbd: allocate image object names with a slab allocator

Message ID 51818ACF.5010202@inktank.com (mailing list archive)
State New, archived
Headers show

Commit Message

Alex Elder May 1, 2013, 9:36 p.m. UTC
The names of objects used for image object requests are always fixed
size.  So create a slab cache to manage them.  Define a new function
rbd_segment_name_free() to match rbd_segment_name() (which is what
supplies the dynamically-allocated name buffer).

This is part of:
    http://tracker.ceph.com/issues/3926

Signed-off-by: Alex Elder <elder@inktank.com>
---
 drivers/block/rbd.c |   34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

 	segment = offset >> rbd_dev->header.obj_order;
@@ -1001,6 +1004,13 @@ static const char *rbd_segment_name(struct
rbd_device *rbd_dev, u64 offset)
 	return name;
 }

+static void rbd_segment_name_free(const char *name)
+{
+	/* The explicit cast here is needed to drop the const qualifier */
+
+	kmem_cache_free(rbd_segment_name_cache, (void *)name);
+}
+
 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
 {
 	u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
@@ -2033,7 +2043,8 @@ static int rbd_img_request_fill(struct
rbd_img_request *img_request,
 		length = rbd_segment_length(rbd_dev, img_offset, resid);
 		obj_request = rbd_obj_request_create(object_name,
 						offset, length, type);
-		kfree(object_name);	/* object request has its own copy */
+		/* object request has its own copy of the object name */
+		rbd_segment_name_free(object_name);
 		if (!obj_request)
 			goto out_unwind;

@@ -5018,17 +5029,32 @@ static int rbd_slab_init(void)
 					sizeof (struct rbd_obj_request),
 					__alignof__(struct rbd_obj_request),
 					0, NULL);
-	if (rbd_obj_request_cache)
-		return 0;
+	if (!rbd_obj_request_cache)
+		goto out_err;

+	rbd_assert(!rbd_segment_name_cache);
+	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
+					MAX_OBJ_NAME_SIZE + 1, 1, 0, NULL);
+	if (rbd_segment_name_cache)
+		return 0;
+out_err:
 	kmem_cache_destroy(rbd_img_request_cache);
 	rbd_img_request_cache = NULL;

+	if (rbd_img_request_cache) {
+		kmem_cache_destroy(rbd_obj_request_cache);
+		rbd_img_request_cache = NULL;
+	}
+
 	return -ENOMEM;
 }

 static void rbd_slab_exit(void)
 {
+	rbd_assert(rbd_segment_name_cache);
+	kmem_cache_destroy(rbd_segment_name_cache);
+	rbd_segment_name_cache = NULL;
+
 	rbd_assert(rbd_obj_request_cache);
 	kmem_cache_destroy(rbd_obj_request_cache);
 	rbd_obj_request_cache = NULL;

Comments

Josh Durgin May 2, 2013, 4:24 p.m. UTC | #1
On 05/01/2013 02:36 PM, Alex Elder wrote:
> The names of objects used for image object requests are always fixed
> size.  So create a slab cache to manage them.  Define a new function
> rbd_segment_name_free() to match rbd_segment_name() (which is what
> supplies the dynamically-allocated name buffer).
>
> This is part of:
>      http://tracker.ceph.com/issues/3926
>
> Signed-off-by: Alex Elder <elder@inktank.com>
> ---
>   drivers/block/rbd.c |   34 ++++++++++++++++++++++++++++++----
>   1 file changed, 30 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 28a5ea3..8d9aeef 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -345,8 +345,11 @@ static DEFINE_SPINLOCK(rbd_dev_list_lock);
>   static LIST_HEAD(rbd_client_list);		/* clients */
>   static DEFINE_SPINLOCK(rbd_client_list_lock);
>
> +/* Slab caches for frequently-allocated structures */
> +
>   static struct kmem_cache	*rbd_img_request_cache;
>   static struct kmem_cache	*rbd_obj_request_cache;
> +static struct kmem_cache	*rbd_segment_name_cache;
>
>   static int rbd_img_request_submit(struct rbd_img_request *img_request);
>
> @@ -985,7 +988,7 @@ static const char *rbd_segment_name(struct
> rbd_device *rbd_dev, u64 offset)
>   	u64 segment;
>   	int ret;
>
> -	name = kmalloc(MAX_OBJ_NAME_SIZE + 1, GFP_NOIO);
> +	name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
>   	if (!name)
>   		return NULL;
>   	segment = offset >> rbd_dev->header.obj_order;
> @@ -1001,6 +1004,13 @@ static const char *rbd_segment_name(struct
> rbd_device *rbd_dev, u64 offset)
>   	return name;
>   }
>
> +static void rbd_segment_name_free(const char *name)
> +{
> +	/* The explicit cast here is needed to drop the const qualifier */
> +
> +	kmem_cache_free(rbd_segment_name_cache, (void *)name);
> +}
> +
>   static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
>   {
>   	u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
> @@ -2033,7 +2043,8 @@ static int rbd_img_request_fill(struct
> rbd_img_request *img_request,
>   		length = rbd_segment_length(rbd_dev, img_offset, resid);
>   		obj_request = rbd_obj_request_create(object_name,
>   						offset, length, type);
> -		kfree(object_name);	/* object request has its own copy */
> +		/* object request has its own copy of the object name */
> +		rbd_segment_name_free(object_name);
>   		if (!obj_request)
>   			goto out_unwind;
>
> @@ -5018,17 +5029,32 @@ static int rbd_slab_init(void)
>   					sizeof (struct rbd_obj_request),
>   					__alignof__(struct rbd_obj_request),
>   					0, NULL);
> -	if (rbd_obj_request_cache)
> -		return 0;
> +	if (!rbd_obj_request_cache)
> +		goto out_err;
>
> +	rbd_assert(!rbd_segment_name_cache);
> +	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
> +					MAX_OBJ_NAME_SIZE + 1, 1, 0, NULL);
> +	if (rbd_segment_name_cache)
> +		return 0;
> +out_err:
>   	kmem_cache_destroy(rbd_img_request_cache);
>   	rbd_img_request_cache = NULL;
>
> +	if (rbd_img_request_cache) {
> +		kmem_cache_destroy(rbd_obj_request_cache);
> +		rbd_img_request_cache = NULL;

Should be rbd_obj_request_cache here and in the condition two lines up.
With that fixed: Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

> +	}
> +
>   	return -ENOMEM;
>   }
>
>   static void rbd_slab_exit(void)
>   {
> +	rbd_assert(rbd_segment_name_cache);
> +	kmem_cache_destroy(rbd_segment_name_cache);
> +	rbd_segment_name_cache = NULL;
> +
>   	rbd_assert(rbd_obj_request_cache);
>   	kmem_cache_destroy(rbd_obj_request_cache);
>   	rbd_obj_request_cache = NULL;
>

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Alex Elder May 2, 2013, 4:30 p.m. UTC | #2
On 05/02/2013 11:24 AM, Josh Durgin wrote:
> On 05/01/2013 02:36 PM, Alex Elder wrote:
>> The names of objects used for image object requests are always fixed
>> size.  So create a slab cache to manage them.  Define a new function
>> rbd_segment_name_free() to match rbd_segment_name() (which is what
>> supplies the dynamically-allocated name buffer).
>>
>> This is part of:
>>      http://tracker.ceph.com/issues/3926
>>
>> Signed-off-by: Alex Elder <elder@inktank.com>
>> ---
>>   drivers/block/rbd.c |   34 ++++++++++++++++++++++++++++++----
>>   1 file changed, 30 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
>> index 28a5ea3..8d9aeef 100644
>> --- a/drivers/block/rbd.c
>> +++ b/drivers/block/rbd.c
>> @@ -345,8 +345,11 @@ static DEFINE_SPINLOCK(rbd_dev_list_lock);
>>   static LIST_HEAD(rbd_client_list);        /* clients */
>>   static DEFINE_SPINLOCK(rbd_client_list_lock);
>>
>> +/* Slab caches for frequently-allocated structures */
>> +
>>   static struct kmem_cache    *rbd_img_request_cache;
>>   static struct kmem_cache    *rbd_obj_request_cache;
>> +static struct kmem_cache    *rbd_segment_name_cache;
>>
>>   static int rbd_img_request_submit(struct rbd_img_request *img_request);
>>
>> @@ -985,7 +988,7 @@ static const char *rbd_segment_name(struct
>> rbd_device *rbd_dev, u64 offset)
>>       u64 segment;
>>       int ret;
>>
>> -    name = kmalloc(MAX_OBJ_NAME_SIZE + 1, GFP_NOIO);
>> +    name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
>>       if (!name)
>>           return NULL;
>>       segment = offset >> rbd_dev->header.obj_order;
>> @@ -1001,6 +1004,13 @@ static const char *rbd_segment_name(struct
>> rbd_device *rbd_dev, u64 offset)
>>       return name;
>>   }
>>
>> +static void rbd_segment_name_free(const char *name)
>> +{
>> +    /* The explicit cast here is needed to drop the const qualifier */
>> +
>> +    kmem_cache_free(rbd_segment_name_cache, (void *)name);
>> +}
>> +
>>   static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
>>   {
>>       u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
>> @@ -2033,7 +2043,8 @@ static int rbd_img_request_fill(struct
>> rbd_img_request *img_request,
>>           length = rbd_segment_length(rbd_dev, img_offset, resid);
>>           obj_request = rbd_obj_request_create(object_name,
>>                           offset, length, type);
>> -        kfree(object_name);    /* object request has its own copy */
>> +        /* object request has its own copy of the object name */
>> +        rbd_segment_name_free(object_name);
>>           if (!obj_request)
>>               goto out_unwind;
>>
>> @@ -5018,17 +5029,32 @@ static int rbd_slab_init(void)
>>                       sizeof (struct rbd_obj_request),
>>                       __alignof__(struct rbd_obj_request),
>>                       0, NULL);
>> -    if (rbd_obj_request_cache)
>> -        return 0;
>> +    if (!rbd_obj_request_cache)
>> +        goto out_err;
>>
>> +    rbd_assert(!rbd_segment_name_cache);
>> +    rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
>> +                    MAX_OBJ_NAME_SIZE + 1, 1, 0, NULL);
>> +    if (rbd_segment_name_cache)
>> +        return 0;
>> +out_err:
>>       kmem_cache_destroy(rbd_img_request_cache);
>>       rbd_img_request_cache = NULL;
>>
>> +    if (rbd_img_request_cache) {
>> +        kmem_cache_destroy(rbd_obj_request_cache);
>> +        rbd_img_request_cache = NULL;
> 
> Should be rbd_obj_request_cache here and in the condition two lines up.
> With that fixed: Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

Got it, I'll fix that, and I'll also fix that GFP
mixup in the previous one.  Thanks for the review.

					-Alex

>> +    }
>> +
>>       return -ENOMEM;
>>   }
>>
>>   static void rbd_slab_exit(void)
>>   {
>> +    rbd_assert(rbd_segment_name_cache);
>> +    kmem_cache_destroy(rbd_segment_name_cache);
>> +    rbd_segment_name_cache = NULL;
>> +
>>       rbd_assert(rbd_obj_request_cache);
>>       kmem_cache_destroy(rbd_obj_request_cache);
>>       rbd_obj_request_cache = NULL;
>>
> 

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diff mbox

Patch

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 28a5ea3..8d9aeef 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -345,8 +345,11 @@  static DEFINE_SPINLOCK(rbd_dev_list_lock);
 static LIST_HEAD(rbd_client_list);		/* clients */
 static DEFINE_SPINLOCK(rbd_client_list_lock);

+/* Slab caches for frequently-allocated structures */
+
 static struct kmem_cache	*rbd_img_request_cache;
 static struct kmem_cache	*rbd_obj_request_cache;
+static struct kmem_cache	*rbd_segment_name_cache;

 static int rbd_img_request_submit(struct rbd_img_request *img_request);

@@ -985,7 +988,7 @@  static const char *rbd_segment_name(struct
rbd_device *rbd_dev, u64 offset)
 	u64 segment;
 	int ret;

-	name = kmalloc(MAX_OBJ_NAME_SIZE + 1, GFP_NOIO);
+	name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
 	if (!name)
 		return NULL;