HAProxy - Load balancer
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Willy Tarreau bc52bec163 MEDIUM: fd: add experimental support for edge-triggered polling
Some of the recent optimizations around the polling to save a few
epoll_ctl() calls have shown that they could also cause some trouble.
However, over time our code base has become totally asynchronous with
I/Os always attempted from the upper layers and only retried at the
bottom, making it look like we're getting closer to EPOLLET support.

There are showstoppers there such as the listeners which cannot support
this. But given that most of the epoll_ctl() dance comes from the
connections, we can try to enable edge-triggered polling on connections.

What this patch does is to add a new global tunable "tune.fd.edge-triggered",
that makes fd_insert() automatically set an et_possible bit on the fd if
the I/O callback is conn_fd_handler. When the epoll code sees an update
for such an FD, it immediately registers it in both directions the first
time and doesn't update it anymore.

On a few tests it proved quite useful with a 14% request rate increase in
a H2->H1 scenario, reducing the epoll_ctl() calls from 2 per request to
2 per connection.

The option is obviously disabled by default as bugs are still expected,
particularly around the subscribe() code where it is possible that some
layers do not always re-attempt reading data after being woken up.
2020-06-19 14:21:46 +02:00
.github CI: extend spellchecker whitelist 2020-05-11 10:10:26 +02:00
contrib BUILD: include: add sys/types before netinet/tcp.h 2020-06-11 11:22:44 +02:00
doc MEDIUM: fd: add experimental support for edge-triggered polling 2020-06-19 14:21:46 +02:00
examples CLEANUP: removed obsolete examples an move a few to better places 2019-06-15 21:25:06 +02:00
include MEDIUM: fd: add experimental support for edge-triggered polling 2020-06-19 14:21:46 +02:00
reg-tests MINOR: sample: Add secure_memcmp converter 2020-06-09 22:04:13 +02:00
scripts REORG: include: move version.h to haproxy/ 2020-06-11 10:18:56 +02:00
src MEDIUM: fd: add experimental support for edge-triggered polling 2020-06-19 14:21:46 +02:00
tests REORG: include: split mini-clist into haproxy/list and list-t.h 2020-06-11 10:18:56 +02:00
.cirrus.yml CI: cirrus-ci: skip reg-tests/connection/proxy_protocol_send_unique_id_alpn.vtc on CentOS 6 2020-05-28 16:51:36 +02:00
.gitignore DOC: create a BRANCHES file to explain the life cycle 2019-06-15 22:00:14 +02:00
.travis.yml CI: travis-ci: use "-O1" for clang builds 2020-06-13 22:59:03 +02:00
BRANCHES DOC: assorted typo fixes in the documentation 2020-03-09 14:45:58 +01:00
CHANGELOG [RELEASE] Released version 2.2-dev9 2020-06-11 10:22:10 +02:00
CONTRIBUTING DOC: assorted typo fixes in the documentation and Makefile 2020-03-06 10:49:55 +01:00
INSTALL BUILD: Makefile: add linux-musl to TARGET 2020-04-16 15:17:13 +02:00
LICENSE LICENSE: add licence exception for OpenSSL 2012-09-07 13:52:26 +02:00
MAINTAINERS REORG: include: split hathreads into haproxy/thread.h and haproxy/thread-t.h 2020-06-11 10:18:56 +02:00
Makefile BUILD: Re-enable -Wimplicit-fallthrough 2020-06-11 16:49:37 +02:00
README DOC: create a BRANCHES file to explain the life cycle 2019-06-15 22:00:14 +02:00
ROADMAP DOC: update the outdated ROADMAP file 2019-06-15 21:59:54 +02:00
SUBVERS BUILD: use format tags in VERDATE and SUBVERS files 2013-12-10 11:22:49 +01:00
VERDATE [RELEASE] Released version 2.2-dev9 2020-06-11 10:22:10 +02:00
VERSION [RELEASE] Released version 2.2-dev9 2020-06-11 10:22:10 +02:00

The HAProxy documentation has been split into a number of different files for
ease of use.

Please refer to the following files depending on what you're looking for :

  - INSTALL for instructions on how to build and install HAProxy
  - BRANCHES to understand the project's life cycle and what version to use
  - LICENSE for the project's license
  - CONTRIBUTING for the process to follow to submit contributions

The more detailed documentation is located into the doc/ directory :

  - doc/intro.txt for a quick introduction on HAProxy
  - doc/configuration.txt for the configuration's reference manual
  - doc/lua.txt for the Lua's reference manual
  - doc/SPOE.txt for how to use the SPOE engine
  - doc/network-namespaces.txt for how to use network namespaces under Linux
  - doc/management.txt for the management guide
  - doc/regression-testing.txt for how to use the regression testing suite
  - doc/peers.txt for the peers protocol reference
  - doc/coding-style.txt for how to adopt HAProxy's coding style
  - doc/internals for developer-specific documentation (not all up to date)