Re: [RFC v3] eal: add bitset type

["Mattias Rönnblom" <hofors@lysator.liu.se>]

On 2024-01-31 17:02, Stephen Hemminger wrote:
> On Wed, 31 Jan 2024 14:13:01 +0100
> Mattias Rönnblom <mattias.ronnblom@ericsson.com> wrote:
> 
>> Introduce a set of functions and macros that operate on sets of bits,
>> kept in arrays of 64-bit elements.
>>
>> RTE bitset is designed for bitsets which are larger than what fits in
>> a single machine word (i.e., 64 bits). For very large bitsets, the
>> <rte_bitmap.h> API may be a more appropriate choice.
>>
>> RFC v3:
>>   * Split the bitset from the htimer patchset, where it was originally
>>     hosted.
>>   * Rebase to current DPDK main.
>>   * Add note that rte_bitset_init() need not be called if bitset words
>>     have already been zeroed.
>>   * Use REGISTER_FAST_TEST instead of REGISTER_TEST_COMMAND.
>>   * Use rte_popcount64() instead of compiler builtin.
>>
>> RFC v2:
>>   * Replaced <sys/types.h> with <stddef.h> include, to properly get
>>     size_t typedef.
>>   * Add <rte_compat.h> to get __rte_experimental in <rte_bitset.h>.
>>
>> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
>> ---
>>   app/test/meson.build         |   1 +
>>   app/test/test_bitset.c       | 645 +++++++++++++++++++++++++
>>   lib/eal/common/meson.build   |   1 +
>>   lib/eal/common/rte_bitset.c  |  29 ++
>>   lib/eal/include/meson.build  |   1 +
>>   lib/eal/include/rte_bitset.h | 884 +++++++++++++++++++++++++++++++++++
>>   lib/eal/version.map          |   3 +
>>   7 files changed, 1564 insertions(+)
>>   create mode 100644 app/test/test_bitset.c
>>   create mode 100644 lib/eal/common/rte_bitset.c
>>   create mode 100644 lib/eal/include/rte_bitset.h
>>
>> diff --git a/app/test/meson.build b/app/test/meson.build
>> index dcc93f4a43..e218be11d8 100644
>> --- a/app/test/meson.build
>> +++ b/app/test/meson.build
>> @@ -32,6 +32,7 @@ source_file_deps = {
>>       'test_bitcount.c': [],
>>       'test_bitmap.c': [],
>>       'test_bitops.c': [],
>> +    'test_bitset.c': [],
>>       'test_bitratestats.c': ['metrics', 'bitratestats', 'ethdev'] + sample_packet_forward_deps,
>>       'test_bpf.c': ['bpf', 'net'],
>>       'test_byteorder.c': [],
>> diff --git a/app/test/test_bitset.c b/app/test/test_bitset.c
>> new file mode 100644
>> index 0000000000..688349b03b
>> --- /dev/null
>> +++ b/app/test/test_bitset.c
>> @@ -0,0 +1,645 @@
>> +/* SPDX-License-Identifier: BSD-3-Clause
>> + * Copyright(c) 2023 Ericsson AB
>> + */
>> +
>> +#include <stdlib.h>
>> +#include <inttypes.h>
>> +
>> +#include <rte_random.h>
>> +
>> +#include <rte_bitset.h>
>> +
>> +#include "test.h"
>> +
>> +#define MAGIC UINT64_C(0xdeadbeefdeadbeef)
>> +
>> +static void
>> +rand_buf(void *buf, size_t n)
>> +{
>> +	size_t i;
>> +
>> +	for (i = 0; i < n; i++)
>> +		((char *)buf)[i] = (char)rte_rand();
> Cast to char unneeded, and you don't want signed character here.
> Use uint8_t

Going through a char pointer is useful in that it never aliases some 
other type. I'll change it to unsigned char.

Thanks.