[dpdk-dev] [PATCH 1/2] bitmap: remove useless code

[dpdk-dev] [PATCH 1/2] bitmap: remove useless code

[Anatoly Burakov]

RTE_BITMAP_OPTIMIZATIONS was never set to 0 and makes no sense
anyway, so remove all code related to it. Also, drop the "likely"
for bsf64 code, because it's a generic function and we cannot
make any assumptions about likely values of incoming arguments.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
---
 lib/librte_eal/common/include/rte_bitmap.h | 33 +---------------------
 1 file changed, 1 insertion(+), 32 deletions(-)

diff --git a/lib/librte_eal/common/include/rte_bitmap.h b/lib/librte_eal/common/include/rte_bitmap.h
index 7a36ce73c..d2ed6204c 100644
--- a/lib/librte_eal/common/include/rte_bitmap.h
+++ b/lib/librte_eal/common/include/rte_bitmap.h
@@ -43,10 +43,6 @@ extern "C" {
 #include <rte_branch_prediction.h>
 #include <rte_prefetch.h>
 
-#ifndef RTE_BITMAP_OPTIMIZATIONS
-#define RTE_BITMAP_OPTIMIZATIONS		         1
-#endif
-
 /* Slab */
 #define RTE_BITMAP_SLAB_BIT_SIZE                 64
 #define RTE_BITMAP_SLAB_BIT_SIZE_LOG2            6
@@ -97,43 +93,16 @@ __rte_bitmap_index2_set(struct rte_bitmap *bmp)
 	bmp->index2 = (((bmp->index1 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2) + bmp->offset1) << RTE_BITMAP_CL_SLAB_SIZE_LOG2);
 }
 
-#if RTE_BITMAP_OPTIMIZATIONS
-
 static inline int
 rte_bsf64(uint64_t slab, uint32_t *pos)
 {
-	if (likely(slab == 0)) {
+	if (slab == 0)
 		return 0;
-	}
 
 	*pos = __builtin_ctzll(slab);
 	return 1;
 }
 
-#else
-
-static inline int
-rte_bsf64(uint64_t slab, uint32_t *pos)
-{
-	uint64_t mask;
-	uint32_t i;
-
-	if (likely(slab == 0)) {
-		return 0;
-	}
-
-	for (i = 0, mask = 1; i < RTE_BITMAP_SLAB_BIT_SIZE; i ++, mask <<= 1) {
-		if (unlikely(slab & mask)) {
-			*pos = i;
-			return 1;
-		}
-	}
-
-	return 0;
-}
-
-#endif
-
 static inline uint32_t
 __rte_bitmap_get_memory_footprint(uint32_t n_bits,
 	uint32_t *array1_byte_offset, uint32_t *array1_slabs,
-- 
2.17.1

[dpdk-dev] [PATCH 2/2] bitmap: deprecate and rename rte_bsf64

[Anatoly Burakov]

Rename rte_bsf64 to rte_bsf64_safe (this is a "safe" version in
that it prevents undefined behavior by checking if incoming
parameter is zero) and move it to common header.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
Acked-by: Jasvinder Singh <jasvinder.singh@intel.com>
---
 doc/guides/rel_notes/deprecation.rst       |  5 +++++
 lib/librte_eal/common/include/rte_bitmap.h | 14 ++++---------
 lib/librte_eal/common/include/rte_common.h | 23 ++++++++++++++++++++++
 3 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 34b28234c..553e99171 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -22,6 +22,11 @@ Deprecation Notices
 
     + ``rte_eal_devargs_type_count``
 
+* eal: function ``rte_bsf64`` in ``rte_bitmap.h`` has been renamed to
+  ``rte_bsf64_safe`` and moved to ``rte_common.h``. A new ``rte_bsf64`` function
+  will be added in the next release in ``rte_common.h`` that follows convention
+  set by existing ``rte_bsf32`` function.
+
 * pci: Several exposed functions are misnamed.
   The following functions are deprecated starting from v17.11 and are replaced:
 
diff --git a/lib/librte_eal/common/include/rte_bitmap.h b/lib/librte_eal/common/include/rte_bitmap.h
index d2ed6204c..77727c828 100644
--- a/lib/librte_eal/common/include/rte_bitmap.h
+++ b/lib/librte_eal/common/include/rte_bitmap.h
@@ -93,14 +93,10 @@ __rte_bitmap_index2_set(struct rte_bitmap *bmp)
 	bmp->index2 = (((bmp->index1 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2) + bmp->offset1) << RTE_BITMAP_CL_SLAB_SIZE_LOG2);
 }
 
-static inline int
+static inline int __rte_deprecated
 rte_bsf64(uint64_t slab, uint32_t *pos)
 {
-	if (slab == 0)
-		return 0;
-
-	*pos = __builtin_ctzll(slab);
-	return 1;
+	return rte_bsf64_safe(slab, pos);
 }
 
 static inline uint32_t
@@ -408,9 +404,8 @@ __rte_bitmap_scan_search(struct rte_bitmap *bmp)
 	value1 = bmp->array1[bmp->index1];
 	value1 &= __rte_bitmap_mask1_get(bmp);
 
-	if (rte_bsf64(value1, &bmp->offset1)) {
+	if (rte_bsf64_safe(value1, &bmp->offset1))
 		return 1;
-	}
 
 	__rte_bitmap_index1_inc(bmp);
 	bmp->offset1 = 0;
@@ -419,9 +414,8 @@ __rte_bitmap_scan_search(struct rte_bitmap *bmp)
 	for (i = 0; i < bmp->array1_size; i ++, __rte_bitmap_index1_inc(bmp)) {
 		value1 = bmp->array1[bmp->index1];
 
-		if (rte_bsf64(value1, &bmp->offset1)) {
+		if (rte_bsf64_safe(value1, &bmp->offset1))
 			return 1;
-		}
 	}
 
 	return 0;
diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 87f0f6302..d115b175c 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -491,6 +491,29 @@ rte_fls_u32(uint32_t x)
 	return (x == 0) ? 0 : 32 - __builtin_clz(x);
 }
 
+/**
+ * Searches the input parameter for the least significant set bit
+ * (starting from zero). Safe version (checks for input parameter being zero).
+ *
+ * @warning ``pos`` must be a valid pointer. It is not checked!
+ *
+ * @param v
+ *     The input parameter.
+ * @param pos
+ *     If ``v`` was not 0, this value will contain position of least significant
+ *     bit within the input parameter.
+ * @return
+ *     Returns 0 if ``v`` was 0, otherwise returns 1.
+ */
+static inline int
+rte_bsf64_safe(uint64_t v, uint32_t *pos)
+{
+	if (v == 0)
+		return 0;
+
+	*pos = __builtin_ctzll(v);
+	return 1;
+}
 
 #ifndef offsetof
 /** Return the offset of a field in a structure. */
-- 
2.17.1

Re: [dpdk-dev] [PATCH 2/2] bitmap: deprecate and rename rte_bsf64

[Thomas Monjalon]

21/11/2018 13:05, Anatoly Burakov:
> Rename rte_bsf64 to rte_bsf64_safe (this is a "safe" version in
> that it prevents undefined behavior by checking if incoming
> parameter is zero) and move it to common header.
> 
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
> Acked-by: Jasvinder Singh <jasvinder.singh@intel.com>

Acked-by: Thomas Monjalon <thomas@monjalon.net>

Re: [dpdk-dev] [PATCH 2/2] bitmap: deprecate and rename rte_bsf64

[Ananyev, Konstantin]

> 
> Rename rte_bsf64 to rte_bsf64_safe (this is a "safe" version in
> that it prevents undefined behavior by checking if incoming
> parameter is zero) and move it to common header.

Probably a stupid one: why to rename?
Why just not fix rte_bsf64 to make it work with zero value,
and keep the same function name?
Konstantin

> 
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
> Acked-by: Jasvinder Singh <jasvinder.singh@intel.com>
> ---
>  doc/guides/rel_notes/deprecation.rst       |  5 +++++
>  lib/librte_eal/common/include/rte_bitmap.h | 14 ++++---------
>  lib/librte_eal/common/include/rte_common.h | 23 ++++++++++++++++++++++
>  3 files changed, 32 insertions(+), 10 deletions(-)
> 
> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> index 34b28234c..553e99171 100644
> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> @@ -22,6 +22,11 @@ Deprecation Notices
> 
>      + ``rte_eal_devargs_type_count``
> 
> +* eal: function ``rte_bsf64`` in ``rte_bitmap.h`` has been renamed to
> +  ``rte_bsf64_safe`` and moved to ``rte_common.h``. A new ``rte_bsf64`` function
> +  will be added in the next release in ``rte_common.h`` that follows convention
> +  set by existing ``rte_bsf32`` function.
> +
>  * pci: Several exposed functions are misnamed.
>    The following functions are deprecated starting from v17.11 and are replaced:
> 
> diff --git a/lib/librte_eal/common/include/rte_bitmap.h b/lib/librte_eal/common/include/rte_bitmap.h
> index d2ed6204c..77727c828 100644
> --- a/lib/librte_eal/common/include/rte_bitmap.h
> +++ b/lib/librte_eal/common/include/rte_bitmap.h
> @@ -93,14 +93,10 @@ __rte_bitmap_index2_set(struct rte_bitmap *bmp)
>  	bmp->index2 = (((bmp->index1 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2) + bmp->offset1) << RTE_BITMAP_CL_SLAB_SIZE_LOG2);
>  }
> 
> -static inline int
> +static inline int __rte_deprecated
>  rte_bsf64(uint64_t slab, uint32_t *pos)
>  {
> -	if (slab == 0)
> -		return 0;
> -
> -	*pos = __builtin_ctzll(slab);
> -	return 1;
> +	return rte_bsf64_safe(slab, pos);
>  }
> 
>  static inline uint32_t
> @@ -408,9 +404,8 @@ __rte_bitmap_scan_search(struct rte_bitmap *bmp)
>  	value1 = bmp->array1[bmp->index1];
>  	value1 &= __rte_bitmap_mask1_get(bmp);
> 
> -	if (rte_bsf64(value1, &bmp->offset1)) {
> +	if (rte_bsf64_safe(value1, &bmp->offset1))
>  		return 1;
> -	}
> 
>  	__rte_bitmap_index1_inc(bmp);
>  	bmp->offset1 = 0;
> @@ -419,9 +414,8 @@ __rte_bitmap_scan_search(struct rte_bitmap *bmp)
>  	for (i = 0; i < bmp->array1_size; i ++, __rte_bitmap_index1_inc(bmp)) {
>  		value1 = bmp->array1[bmp->index1];
> 
> -		if (rte_bsf64(value1, &bmp->offset1)) {
> +		if (rte_bsf64_safe(value1, &bmp->offset1))
>  			return 1;
> -		}
>  	}
> 
>  	return 0;
> diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
> index 87f0f6302..d115b175c 100644
> --- a/lib/librte_eal/common/include/rte_common.h
> +++ b/lib/librte_eal/common/include/rte_common.h
> @@ -491,6 +491,29 @@ rte_fls_u32(uint32_t x)
>  	return (x == 0) ? 0 : 32 - __builtin_clz(x);
>  }
> 
> +/**
> + * Searches the input parameter for the least significant set bit
> + * (starting from zero). Safe version (checks for input parameter being zero).
> + *
> + * @warning ``pos`` must be a valid pointer. It is not checked!
> + *
> + * @param v
> + *     The input parameter.
> + * @param pos
> + *     If ``v`` was not 0, this value will contain position of least significant
> + *     bit within the input parameter.
> + * @return
> + *     Returns 0 if ``v`` was 0, otherwise returns 1.
> + */
> +static inline int
> +rte_bsf64_safe(uint64_t v, uint32_t *pos)
> +{
> +	if (v == 0)
> +		return 0;
> +
> +	*pos = __builtin_ctzll(v);
> +	return 1;
> +}
> 
>  #ifndef offsetof
>  /** Return the offset of a field in a structure. */
> --
> 2.17.1

Re: [dpdk-dev] [PATCH 2/2] bitmap: deprecate and rename rte_bsf64

[Thomas Monjalon]

22/11/2018 19:56, Ananyev, Konstantin:
> > Rename rte_bsf64 to rte_bsf64_safe (this is a "safe" version in
> > that it prevents undefined behavior by checking if incoming
> > parameter is zero) and move it to common header.
> 
> Probably a stupid one: why to rename?
> Why just not fix rte_bsf64 to make it work with zero value,
> and keep the same function name?

Because there are different parameters and returned value
than rte_bsf32.
In the next release, we will have rte_bsf64 function,
behaving as rte_bsf32.
This is explained in the deprecation notice.

[...]
> > +static inline int
> > +rte_bsf64_safe(uint64_t v, uint32_t *pos)

Re: [dpdk-dev] [PATCH 2/2] bitmap: deprecate and rename rte_bsf64

[Thomas Monjalon]

22/11/2018 18:04, Thomas Monjalon:
> 21/11/2018 13:05, Anatoly Burakov:
> > Rename rte_bsf64 to rte_bsf64_safe (this is a "safe" version in
> > that it prevents undefined behavior by checking if incoming
> > parameter is zero) and move it to common header.
> > 
> > Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> > Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
> > Acked-by: Jasvinder Singh <jasvinder.singh@intel.com>
> 
> Acked-by: Thomas Monjalon <thomas@monjalon.net>

Series applied, thanks