[dpdk-dev] [PATCH v3 0/3] timer library enhancement

Erik Gabriel Carrillo erik.g.carrillo at intel.com
Thu Sep 14 00:05:05 CEST 2017

In the current implementation of the DPDK timer library, timers can be
created and set to be handled by a target lcore by adding it to a
skiplist that corresponds to that lcore.  However, if an application
enables multiple lcores, and each of these lcores repeatedly attempts
to install timers on the same target lcore, overall application
throughput will be reduced as all lcores contend to acquire the lock
guarding the single skiplist of pending timers. 

This patchset addresses this scenario by adding an option to enable an
array of skiplists in each lcore's priv_timer struct. Then, when lcore i
installs a timer on lcore k, the timer will be added to the ith skiplist
for lcore k.  If lcore j installs a timer on lcore k simultaneously,
lcores i and j can both proceed since they will be acquiring different
locks for different lists. This functionality is off by default, and
can be enabled via a new function.

When lcore k processes its pending timers, if the multiple pending list
option is enabled, it will traverse skiplists in its array and acquire 
the current skiplist's lock while a run list is broken out; meanwhile,
all other lists can continue to be modified.  Then, all run lists for
lcore k are collected and traversed together so timers are executed in
their relative order. If the multiple pending list option is not enabled
(the default), only a single list will be traversed, as before.

Erik Gabriel Carrillo (3):
  timer: add multiple pending lists option for each lcore
  timer: handle timers installed from non-EAL threads
  doc: update timer lib docs

 doc/guides/prog_guide/timer_lib.rst    |  27 ++-
 doc/guides/rel_notes/release_17_11.rst |   7 +
 lib/librte_timer/rte_timer.c           | 384 ++++++++++++++++++++++-----------
 lib/librte_timer/rte_timer.h           |  29 ++-
 lib/librte_timer/rte_timer_version.map |   6 +
 5 files changed, 319 insertions(+), 134 deletions(-)


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