numam-dpdk/doc
Honnappa Nagarahalli e605a1d36c hash: add lock-free r/w concurrency
Add lock-free read-write concurrency. This is achieved by the
following changes.

1) Add memory ordering to avoid race conditions. The only race
condition that can occur is -  using the key store element
before the key write is completed. Hence, while inserting the element
the release memory order is used. Any other race condition is caught
by the key comparison. Memory orderings are added only where needed.
For ex: reads in the writer's context do not need memory ordering
as there is a single writer.

key_idx in the bucket entry and pdata in the key store element are
used for synchronisation. key_idx is used to release an inserted
entry in the bucket to the reader. Use of pdata for synchronisation
is required due to updation of an existing entry where-in only
the pdata is updated without updating key_idx.

2) Reader-writer concurrency issue, caused by moving the keys
to their alternative locations during key insert, is solved
by introducing a global counter(tbl_chng_cnt) indicating a
change in table.

3) Add the flag to enable reader-writer concurrency during
run time.

Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Yipeng Wang <yipeng1.wang@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
2018-10-26 12:50:43 +02:00
..
api doc: add deprecated list in doxygen 2018-10-25 16:35:52 +02:00
guides hash: add lock-free r/w concurrency 2018-10-26 12:50:43 +02:00
logo doc: change theme of guides 2015-12-13 22:30:47 +01:00
build-sdk-meson.txt build: generate API documentation with meson 2018-09-18 15:50:54 +02:00
build-sdk-quick.txt doc: add tags and cscope make targets to quick help 2017-08-05 11:04:47 +02:00
meson.build build: generate API documentation with meson 2018-09-18 15:50:54 +02:00