[dpdk-dev] [PATCH 1/2] test/bitmap: add test case to scan after half cline is cleared

[dpdk-dev] [PATCH 1/2] test/bitmap: add test case to scan after half cline is cleared

[Nithin Dabilpuram]

Add a test case to test scan operation post clear of half
cacheline of slabs.

Also fix meson.build to include test_bitmap.c in the compilation.

Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
---
 app/test/meson.build   |  1 +
 app/test/test_bitmap.c | 34 +++++++++++++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/app/test/meson.build b/app/test/meson.build
index 94fd39f..bb06a92 100644
--- a/app/test/meson.build
+++ b/app/test/meson.build
@@ -13,6 +13,7 @@ test_sources = files('commands.c',
 	'test_atomic.c',
 	'test_barrier.c',
 	'test_bitops.c',
+	'test_bitmap.c',
 	'test_bpf.c',
 	'test_byteorder.c',
 	'test_cmdline.c',
diff --git a/app/test/test_bitmap.c b/app/test/test_bitmap.c
index a8204d3..70d8fff 100644
--- a/app/test/test_bitmap.c
+++ b/app/test/test_bitmap.c
@@ -16,9 +16,10 @@
 static int
 test_bitmap_scan_operations(struct rte_bitmap *bmp)
 {
-	uint32_t pos = 0;
 	uint64_t slab1_magic = 0xBADC0FFEEBADF00D;
 	uint64_t slab2_magic = 0xFEEDDEADDEADF00D;
+	uint32_t pos = 0, start_pos;
+	int i, nb_clear, nb_set;
 	uint64_t out_slab = 0;
 
 	rte_bitmap_reset(bmp);
@@ -70,6 +71,37 @@ test_bitmap_scan_operations(struct rte_bitmap *bmp)
 		return TEST_FAILED;
 	}
 
+	/* Test scan when a cline is half full */
+	rte_bitmap_reset(bmp);
+	for (i = 0; i < MAX_BITS; i++)
+		rte_bitmap_set(bmp, i);
+
+	nb_clear = RTE_MIN(RTE_BITMAP_CL_BIT_SIZE / 2, MAX_BITS);
+	for (i = 0; i < nb_clear; i++)
+		rte_bitmap_clear(bmp, i);
+
+	/* Find remaining bits set in bmp */
+	__rte_bitmap_scan_init(bmp);
+
+	if (rte_bitmap_scan(bmp, &pos, &out_slab) != 1) {
+		printf("Initial scan failed with half CL empty.\n");
+		return TEST_FAILED;
+	}
+
+	start_pos = pos;
+	nb_set = 0;
+	do {
+		nb_set += __builtin_popcountll(out_slab);
+		if (!rte_bitmap_scan(bmp, &pos, &out_slab))
+			break;
+	} while (pos != start_pos);
+
+	if ((nb_clear + nb_set) != MAX_BITS) {
+		printf("Scan failed to find all set bits. "
+		       "Expected %u, found %u.\n", MAX_BITS - nb_clear, nb_set);
+		return TEST_FAILED;
+	}
+
 	return TEST_SUCCESS;
 }
 
-- 
2.8.4

[dpdk-dev] [PATCH 2/2] bitmap: fix bitmap not empty API for 128B cacheline

[Nithin Dabilpuram]

Currently bitmap line not empty check API assumes cache line
of 64B and only checks 8 slabs. Since in 128B cacheline, we
have 16 slabs per cacheline, plt_bitmap_clear() will mark
complete line as empty as soon as 8 slabs are full thereby
breaking bitmap scan functionality. Fix it by defining new
__plt_bitmap_line_not_empty() for 128B cacheline platform.

Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
---
 lib/librte_eal/include/rte_bitmap.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/lib/librte_eal/include/rte_bitmap.h b/lib/librte_eal/include/rte_bitmap.h
index 7c90ef3..d9a1b54 100644
--- a/lib/librte_eal/include/rte_bitmap.h
+++ b/lib/librte_eal/include/rte_bitmap.h
@@ -417,6 +417,7 @@ rte_bitmap_set_slab(struct rte_bitmap *bmp, uint32_t pos, uint64_t slab)
 	*slab1 |= 1llu << offset1;
 }
 
+#if RTE_BITMAP_CL_SLAB_SIZE == 8
 static inline uint64_t
 __rte_bitmap_line_not_empty(uint64_t *slab2)
 {
@@ -432,6 +433,30 @@ __rte_bitmap_line_not_empty(uint64_t *slab2)
 	return v1 | v3;
 }
 
+#elif RTE_BITMAP_CL_SLAB_SIZE == 16
+static inline uint64_t
+__rte_bitmap_line_not_empty(uint64_t *slab2)
+{
+	uint64_t v1, v2, v3, v4, v5, v6, v7, v8;
+
+	v1 = slab2[0] | slab2[1];
+	v2 = slab2[2] | slab2[3];
+	v3 = slab2[4] | slab2[5];
+	v4 = slab2[6] | slab2[7];
+	v5 = slab2[8] | slab2[9];
+	v6 = slab2[10] | slab2[11];
+	v7 = slab2[12] | slab2[13];
+	v8 = slab2[14] | slab2[15];
+	v1 |= v2;
+	v3 |= v4;
+	v5 |= v6;
+	v7 |= v8;
+
+	return v1 | v3 | v5 | v7;
+}
+
+#endif
+
 /**
  * Bitmap bit clear
  *
-- 
2.8.4

Re: [dpdk-dev] [PATCH 2/2] bitmap: fix bitmap not empty API for 128B cacheline

[Dumitrescu, Cristian]

> -----Original Message-----
> From: Nithin Dabilpuram <ndabilpuram@marvell.com>
> Sent: Monday, December 14, 2020 10:29 AM
> To: Dumitrescu, Cristian <cristian.dumitrescu@intel.com>
> Cc: jerinj@marvell.com; dev@dpdk.org; Nithin Dabilpuram
> <ndabilpuram@marvell.com>
> Subject: [PATCH 2/2] bitmap: fix bitmap not empty API for 128B cacheline
> 
> Currently bitmap line not empty check API assumes cache line
> of 64B and only checks 8 slabs. Since in 128B cacheline, we
> have 16 slabs per cacheline, plt_bitmap_clear() will mark
> complete line as empty as soon as 8 slabs are full thereby
> breaking bitmap scan functionality. Fix it by defining new
> __plt_bitmap_line_not_empty() for 128B cacheline platform.
> 
> Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
> ---
>  lib/librte_eal/include/rte_bitmap.h | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/lib/librte_eal/include/rte_bitmap.h
> b/lib/librte_eal/include/rte_bitmap.h
> index 7c90ef3..d9a1b54 100644
> --- a/lib/librte_eal/include/rte_bitmap.h
> +++ b/lib/librte_eal/include/rte_bitmap.h
> @@ -417,6 +417,7 @@ rte_bitmap_set_slab(struct rte_bitmap *bmp,
> uint32_t pos, uint64_t slab)
>  	*slab1 |= 1llu << offset1;
>  }
> 
> +#if RTE_BITMAP_CL_SLAB_SIZE == 8
>  static inline uint64_t
>  __rte_bitmap_line_not_empty(uint64_t *slab2)
>  {
> @@ -432,6 +433,30 @@ __rte_bitmap_line_not_empty(uint64_t *slab2)
>  	return v1 | v3;
>  }
> 
> +#elif RTE_BITMAP_CL_SLAB_SIZE == 16
> +static inline uint64_t
> +__rte_bitmap_line_not_empty(uint64_t *slab2)
> +{
> +	uint64_t v1, v2, v3, v4, v5, v6, v7, v8;
> +
> +	v1 = slab2[0] | slab2[1];
> +	v2 = slab2[2] | slab2[3];
> +	v3 = slab2[4] | slab2[5];
> +	v4 = slab2[6] | slab2[7];
> +	v5 = slab2[8] | slab2[9];
> +	v6 = slab2[10] | slab2[11];
> +	v7 = slab2[12] | slab2[13];
> +	v8 = slab2[14] | slab2[15];
> +	v1 |= v2;
> +	v3 |= v4;
> +	v5 |= v6;
> +	v7 |= v8;
> +
> +	return v1 | v3 | v5 | v7;
> +}
> +
> +#endif
> +
>  /**
>   * Bitmap bit clear
>   *
> --
> 2.8.4

Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>

[dpdk-dev] [PATCH v2 1/2] test/bitmap: test scan after half cline is cleared

[Nithin Dabilpuram]

Add a test case to test scan operation post clear of half
cacheline of slabs.

Also fix meson.build to include test_bitmap.c in the compilation.

Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
---

v2:
- No change

 app/test/meson.build   |  1 +
 app/test/test_bitmap.c | 34 +++++++++++++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/app/test/meson.build b/app/test/meson.build
index 94fd39f..bb06a92 100644
--- a/app/test/meson.build
+++ b/app/test/meson.build
@@ -13,6 +13,7 @@ test_sources = files('commands.c',
 	'test_atomic.c',
 	'test_barrier.c',
 	'test_bitops.c',
+	'test_bitmap.c',
 	'test_bpf.c',
 	'test_byteorder.c',
 	'test_cmdline.c',
diff --git a/app/test/test_bitmap.c b/app/test/test_bitmap.c
index a8204d3..70d8fff 100644
--- a/app/test/test_bitmap.c
+++ b/app/test/test_bitmap.c
@@ -16,9 +16,10 @@
 static int
 test_bitmap_scan_operations(struct rte_bitmap *bmp)
 {
-	uint32_t pos = 0;
 	uint64_t slab1_magic = 0xBADC0FFEEBADF00D;
 	uint64_t slab2_magic = 0xFEEDDEADDEADF00D;
+	uint32_t pos = 0, start_pos;
+	int i, nb_clear, nb_set;
 	uint64_t out_slab = 0;
 
 	rte_bitmap_reset(bmp);
@@ -70,6 +71,37 @@ test_bitmap_scan_operations(struct rte_bitmap *bmp)
 		return TEST_FAILED;
 	}
 
+	/* Test scan when a cline is half full */
+	rte_bitmap_reset(bmp);
+	for (i = 0; i < MAX_BITS; i++)
+		rte_bitmap_set(bmp, i);
+
+	nb_clear = RTE_MIN(RTE_BITMAP_CL_BIT_SIZE / 2, MAX_BITS);
+	for (i = 0; i < nb_clear; i++)
+		rte_bitmap_clear(bmp, i);
+
+	/* Find remaining bits set in bmp */
+	__rte_bitmap_scan_init(bmp);
+
+	if (rte_bitmap_scan(bmp, &pos, &out_slab) != 1) {
+		printf("Initial scan failed with half CL empty.\n");
+		return TEST_FAILED;
+	}
+
+	start_pos = pos;
+	nb_set = 0;
+	do {
+		nb_set += __builtin_popcountll(out_slab);
+		if (!rte_bitmap_scan(bmp, &pos, &out_slab))
+			break;
+	} while (pos != start_pos);
+
+	if ((nb_clear + nb_set) != MAX_BITS) {
+		printf("Scan failed to find all set bits. "
+		       "Expected %u, found %u.\n", MAX_BITS - nb_clear, nb_set);
+		return TEST_FAILED;
+	}
+
 	return TEST_SUCCESS;
 }
 
-- 
2.8.4

[dpdk-dev] [PATCH v2 2/2] bitmap: modify bitmap not empty API for 128B cacheline

[Nithin Dabilpuram]

Currently bitmap line not empty check API assumes cache line
of 64B and only checks 8 slabs. Since in 128B cacheline, we
have 16 slabs per cacheline, rte_bitmap_clear() will mark
complete line as empty as soon as 8 slabs are empty thereby
breaking bitmap scan functionality. Fix it by defining new
__rte_bitmap_line_not_empty() for 128B cacheline platform.

Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
---

v2:
- Fix issue with commit message and add acked-by from Cristian.

 lib/librte_eal/include/rte_bitmap.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/lib/librte_eal/include/rte_bitmap.h b/lib/librte_eal/include/rte_bitmap.h
index 7c90ef3..d9a1b54 100644
--- a/lib/librte_eal/include/rte_bitmap.h
+++ b/lib/librte_eal/include/rte_bitmap.h
@@ -417,6 +417,7 @@ rte_bitmap_set_slab(struct rte_bitmap *bmp, uint32_t pos, uint64_t slab)
 	*slab1 |= 1llu << offset1;
 }
 
+#if RTE_BITMAP_CL_SLAB_SIZE == 8
 static inline uint64_t
 __rte_bitmap_line_not_empty(uint64_t *slab2)
 {
@@ -432,6 +433,30 @@ __rte_bitmap_line_not_empty(uint64_t *slab2)
 	return v1 | v3;
 }
 
+#elif RTE_BITMAP_CL_SLAB_SIZE == 16
+static inline uint64_t
+__rte_bitmap_line_not_empty(uint64_t *slab2)
+{
+	uint64_t v1, v2, v3, v4, v5, v6, v7, v8;
+
+	v1 = slab2[0] | slab2[1];
+	v2 = slab2[2] | slab2[3];
+	v3 = slab2[4] | slab2[5];
+	v4 = slab2[6] | slab2[7];
+	v5 = slab2[8] | slab2[9];
+	v6 = slab2[10] | slab2[11];
+	v7 = slab2[12] | slab2[13];
+	v8 = slab2[14] | slab2[15];
+	v1 |= v2;
+	v3 |= v4;
+	v5 |= v6;
+	v7 |= v8;
+
+	return v1 | v3 | v5 | v7;
+}
+
+#endif
+
 /**
  * Bitmap bit clear
  *
-- 
2.8.4

Re: [dpdk-dev] [PATCH v2 2/2] bitmap: modify bitmap not empty API for 128B cacheline

[Thomas Monjalon]

05/01/2021 09:57, Nithin Dabilpuram:
> Currently bitmap line not empty check API assumes cache line
> of 64B and only checks 8 slabs. Since in 128B cacheline, we
> have 16 slabs per cacheline, rte_bitmap_clear() will mark
> complete line as empty as soon as 8 slabs are empty thereby
> breaking bitmap scan functionality. Fix it by defining new
> __rte_bitmap_line_not_empty() for 128B cacheline platform.
> 
> Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
> Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
> ---
> 
> v2:
> - Fix issue with commit message and add acked-by from Cristian.

It seems you don't want to consider this patch as a fix,
so no backport request.

Applied with title "bitmap: support 128-byte cacheline in empty check", thanks.