| Message ID | cover.1553263445.git.pabeni@redhat.com |
|---|---|
| Headers | show |
| Series | net: dev: BYPASS for lockless qdisc | expand |
From: Paolo Abeni <pabeni@redhat.com> Date: Fri, 22 Mar 2019 16:01:54 +0100 > This patch series is aimed at improving xmit performances of lockless qdisc > in the uncontended scenario. > > After the lockless refactor pfifo_fast can't leverage the BYPASS optimization. > Due to retpolines the overhead for the avoidables enqueue and dequeue operations > has increased and we see measurable regressions. > > The first patch introduces the BYPASS code path for lockless qdisc, and the > second one optimizes such path further. Overall this avoids up to 3 indirect > calls per xmit packet. Detailed performance figures are reported in the 2nd > patch. > > v2 -> v3: > - qdisc_is_empty() has a const argument (Eric) > > v1 -> v2: > - use really an 'empty' flag instead of 'not_empty', as > suggested by Eric Looks great, series applied, thanks Paolo.
This patch series is aimed at improving xmit performances of lockless qdisc in the uncontended scenario. After the lockless refactor pfifo_fast can't leverage the BYPASS optimization. Due to retpolines the overhead for the avoidables enqueue and dequeue operations has increased and we see measurable regressions. The first patch introduces the BYPASS code path for lockless qdisc, and the second one optimizes such path further. Overall this avoids up to 3 indirect calls per xmit packet. Detailed performance figures are reported in the 2nd patch. v2 -> v3: - qdisc_is_empty() has a const argument (Eric) v1 -> v2: - use really an 'empty' flag instead of 'not_empty', as suggested by Eric Paolo Abeni (2): net: sched: add empty status flag for NOLOCK qdisc net: dev: introduce support for sch BYPASS for lockless qdisc include/net/sch_generic.h | 11 +++++++++++ net/core/dev.c | 9 +++++++++ net/sched/sch_generic.c | 3 +++ 3 files changed, 23 insertions(+)