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[v3,0/2] bitmap: add create bitmap with all bits set

Message ID 1586522787-403236-1-git-send-email-suanmingm@mellanox.com (mailing list archive)
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Suanming Mou April 10, 2020, 12:46 p.m. UTC
Currently, in the case to use bitmap as resource allocator, after
bitmap creation, all the bitmap bits should be set to indicate the
bit available. Every time when allocate one bit, search for the set
bits and clear it to make it in use.

Add a new rte_bitmap_init_with_all_set() function to have a quick
fill up the bitmap bits.

Comparing with the case create the bitmap as empty and set the bitmap
one by one, the new function costs less cycles.

For bitmap with 1000 bits, create the bitmap with all bits set costs 754
cycles, while set one by one costs 14194. CPU info as below:
Intel(R) Xeon(R) Silver 4110 CPU @ 2.10GHz

v3 updates:
1. Implement individual rte_bitmap_init_with_all_set() function.
2. Add new function to clear the overhead bits.

v2 updates:
1. Split the common part to __rte_bitmap_init().
2. Set the slab bits more customized.

Suanming Mou (2):
  bitmap: add create bitmap with all bits set
  test/bitmap: add bitmap create with all bits set case

 app/test/test_bitmap.c              | 57 ++++++++++++++++++++++++++-
 lib/librte_eal/include/rte_bitmap.h | 78 +++++++++++++++++++++++++++++++++++++
 2 files changed, 134 insertions(+), 1 deletion(-)