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[0/2] ethdev: make rte flow API thread safe

Message ID 1601194817-208834-1-git-send-email-suanmingm@nvidia.com (mailing list archive)
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Series ethdev: make rte flow API thread safe | expand


Suanming Mou Sept. 27, 2020, 8:20 a.m. UTC
Currently, the rte flow functions are not defined as thread safety.
DPDK applications either call the functions in single thread or add
locks around the functions for the critical section.

For PMDs support the flow operations thread safe natively, the
redundant protection in application hurts the performance of the
rte flow operation functions.

And the restriction of thread safety not guaranteed for the rte
flow functions also limits the applications' expectation.

This feature is going to change the rte flow functions to be thread
safety. As different PMDs have different flow operations, some may
support thread safety already and others may not. For PMDs don't
support flow thread safe operation, a new lock is defined in ethdev
in order to protects thread unsafe PMDs from rte flow level.

A new RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE device flag is added to
determine whether the PMD supports thread safe flow operation or not.
For PMDs support thread safe flow operations, set the
RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE flag, rte flow level functions will
skip the thread safe helper lock for these PMDs. Again the rte flow
level thread safe lock only works when PMD operation functions are
not thread safety.

For the PMDs which don't want the default mutex lock, just set the
flag in the PMD, and add the perfer type of lock in the PMD. Then
the default mutex lock is easily replaced by the PMD level lock.

The change has no effect on the current DPDK applications. No change
is required for the current DPDK applications. If no lock contention
with the added rte flow level mutex, the mutex only does the atomic
increasing in pthread_mutex_lock() and decreasing in
pthread_mutex_unlock(). No futex() syscall will be involved.

Suanming Mou (2):
  eal/windows: add pthread mutex lock
  ethdev: make rte flow API thread safe

 doc/guides/prog_guide/rte_flow.rst       |  7 ++-
 drivers/net/mlx5/linux/mlx5_os.c         |  2 +
 lib/librte_eal/windows/include/pthread.h | 46 +++++++++++++++++
 lib/librte_ethdev/rte_ethdev.c           |  2 +
 lib/librte_ethdev/rte_ethdev.h           |  2 +
 lib/librte_ethdev/rte_ethdev_core.h      |  4 ++
 lib/librte_ethdev/rte_flow.c             | 84 ++++++++++++++++++++++++--------
 7 files changed, 124 insertions(+), 23 deletions(-)