github-ci: switch off swap use

Github Actions provides hosts for Linux base runners in the following
configurations:

  2 Cores
  7 Gb memory
  4 Gb swap memory

To avoid of issues with hanging/slowing tests on high memory use
like [1], hosts configurations must avoid of swap memory use. All
of the tests workflows run inside dockers containers. This patch
sets in docker run configurations memory limits based on current
github actions hosts - 7Gb memory w/o swap memory increase.

Checked 10 full runs (29 workflows in each run used the change) and
got single failed test on gevent() routine in test-run. This result much
better than w/o this patch when 3-4 of workflows fail on each full run.

It could happen because swap began to be used after 40% of RAM was used:

  cat /sys/fs/cgroup/memory/memory.swappiness
  60

This default vm.swappiness value of 60% represents the percentage of
the free memory before activating swap. The lower the value, the less
swapping is used and the more memory pages are kept in physical memory.

This swappiness value was not enough tuned for performance testing as
suggested in [2]. For performance testing better to use lower values
like 10% or even better not use swap at all.

For Github Actions host configurations with 7Gb RAM it means that after
2.8Gb RAM was used swap began to use. But in testing we have some tests
that use 2.5Gb of RAM like 'box/net_msg_max.test.lua' and memory
fragmentation could cause after the test run swap use [3].

Also found that disk cache could use some RAM and it also was the cause
of fast memory use and start swapping. It can be periodically dropped
from memory [4] using 'drop_cache' system value setup, but it won't fix
the overall issue with swap use.

After freed cached pages in RAM another system kernel option can be
tuned [5][6] 'vfs_cache_pressure'. This percentage value controls the
tendency of the kernel to reclaim the memory which is used for caching
of directory and inode objects. Increasing it significantly beyond
default value of 100 may have negative performance impact. Reclaim code
needs to take various locks to find freeable directory and inode
objects. With 'vfs_cache_pressure=1000', it will look for ten times more
freeable objects than there are. This patch won't do this change, but
it can be done as the next change.

To fix the issue there were made changes:

 - For jobs that run tests and use actions/environment and don't use
   Github Actions container tag, it was set 'sudo swapoff -a' command
   in actions/environment action.

 - For jobs that run tests and use Github Actions container tag the
   previous solution doesn't work. It was decided to hard-code the
   memory value based on found on Github Actions hosts memory size
   7Gb. It was set for Github container tag as additional options:
     options: '--init --memory=7G --memory-swap=7G'
   This changes were made temporary till these containers tags will
   be removed within resolving tarantool/tarantool-qa#101 issue for
   workflows:
     debug_coverage
     release
     release_asan_clang11
     release_clang
     release_lto
     release_lto_clang11
     static_build
     static_build_cmake_linux

 - For VMware VMs like with FreeBSD added 'sudo swapoff -a' command
   before build commands.

 - For OSX on Github actions hosts swapping already disabled:
     sysctl vm.swapusage
     vm.swapusage: total = 0.00M  used = 0.00M  free = 0.00M  (encrypted)
   Also manual switching off swap currently not possible due to do
   System Integrity Protection (SIP) must be disabled [7], but we
   don't have such access on Github Actions hosts. For local hosts
   it must be done manually with [8]:
     sudo nvram boot-args="vm_compressor=2"
   Added swap status control to be sure that host correctly configured:
     sysctl vm.swapusage

Closes tarantool/tarantool-qa#99

[1]: tarantool/tarantool-qa#93
[2]: https://linuxhint.com/understanding_vm_swappiness/
[3]: https://unix.stackexchange.com/questions/2658/why-use-swap-when-there-is-more-than-enough-free-space-in-ram
[4]: https://kubuntu.ru/node/13082
[5]: https://www.kernel.org/doc/Documentation/sysctl/vm.txt
[6]: http://devhead.ru/read/uskorenie-raboty-linux
[7]: https://osxdaily.com/2010/10/08/mac-virtual-memory-swap/
[8]: https://gist.github.com/dan-palmer/3082266#gistcomment-3667471

Author: avtikhon

.github/actions/environment/action.yml

@@ -8,4 +8,13 @@ runs:
         echo TEST_TIMEOUT=310 | tee -a $GITHUB_ENV
         echo NO_OUTPUT_TIMEOUT=320 | tee -a $GITHUB_ENV
         echo PRESERVE_ENVVARS=REPLICATION_SYNC_TIMEOUT,TEST_TIMEOUT,NO_OUTPUT_TIMEOUT | tee -a $GITHUB_ENV
+        # This switching off swap command will not work as github step
+        # run from inside github 'container' tag. Also it will fail to
+        # run from it. So running it only outside of docker container.
+        # NOTE: To switch off swap from inside github 'container' tag
+        # additional memory flags should be added to its 'options' tag:
+        #   options: '--memory=<some value, like 7G> --memory-swap=<the same value as for memory option>'
+        if cat /proc/1/sched | head -n1 | grep "[^init |^systemd ]" && [ -e /sbin/swapoff ] ; then
+            sudo /sbin/swapoff -a
+        fi
       shell: bash

.github/workflows/debug_coverage.yml

@@ -29,7 +29,9 @@ jobs:
       # Our testing expects that the init process (PID 1) will
       # reap orphan processes. At least the following test leans
       # on it: app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua.
-      options: '--init'
+      # Memory size hard coding will be removed within resolving issue
+      #   http://github.com/tarantool/tarantool-qa/issues/101
+      options: '--init --memory=7G --memory-swap=7G'
 
     steps:
       - uses: actions/checkout@v1

.github/workflows/release.yml

@@ -29,7 +29,9 @@ jobs:
       # Our testing expects that the init process (PID 1) will
       # reap orphan processes. At least the following test leans
       # on it: app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua.
-      options: '--init'
+      # Memory size hard coding will be removed within resolving issue
+      #   http://github.com/tarantool/tarantool-qa/issues/101
+      options: '--init --memory=7G --memory-swap=7G'
 
     steps:
       - uses: actions/checkout@v1

.github/workflows/release_asan_clang11.yml

@@ -29,7 +29,9 @@ jobs:
       # Our testing expects that the init process (PID 1) will
       # reap orphan processes. At least the following test leans
       # on it: app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua.
-      options: '--init'
+      # Memory size hard coding will be removed within resolving issue
+      #   http://github.com/tarantool/tarantool-qa/issues/101
+      options: '--init --memory=7G --memory-swap=7G'
 
     steps:
       - uses: actions/[email protected]

.github/workflows/release_clang.yml

@@ -29,7 +29,9 @@ jobs:
       # Our testing expects that the init process (PID 1) will
       # reap orphan processes. At least the following test leans
       # on it: app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua.
-      options: '--init'
+      # Memory size hard coding will be removed within resolving issue
+      #   http://github.com/tarantool/tarantool-qa/issues/101
+      options: '--init --memory=7G --memory-swap=7G'
 
     steps:
       - uses: actions/checkout@v1

.github/workflows/release_lto.yml

@@ -29,7 +29,9 @@ jobs:
       # Our testing expects that the init process (PID 1) will
       # reap orphan processes. At least the following test leans
       # on it: app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua.
-      options: '--init'
+      # Memory size hard coding will be removed within resolving issue
+      #   http://github.com/tarantool/tarantool-qa/issues/101
+      options: '--init --memory=7G --memory-swap=7G'
 
     steps:
       - uses: actions/[email protected]

.github/workflows/release_lto_clang11.yml

@@ -29,7 +29,9 @@ jobs:
       # Our testing expects that the init process (PID 1) will
       # reap orphan processes. At least the following test leans
       # on it: app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua.
-      options: '--init'
+      # Memory size hard coding will be removed within resolving issue
+      #   http://github.com/tarantool/tarantool-qa/issues/101
+      options: '--init --memory=7G --memory-swap=7G'
 
     steps:
       - uses: actions/[email protected]

.github/workflows/static_build.yml

@@ -29,7 +29,9 @@ jobs:
       # Our testing expects that the init process (PID 1) will
       # reap orphan processes. At least the following test leans
       # on it: app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua.
-      options: '--init'
+      # Memory size hard coding will be removed within resolving issue
+      #   http://github.com/tarantool/tarantool-qa/issues/101
+      options: '--init --memory=7G --memory-swap=7G'
 
     steps:
       - uses: actions/checkout@v1

.github/workflows/static_build_cmake_linux.yml

@@ -29,7 +29,9 @@ jobs:
       # Our testing expects that the init process (PID 1) will
       # reap orphan processes. At least the following test leans
       # on it: app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua.
-      options: '--init'
+      # Memory size hard coding will be removed within resolving issue
+      #   http://github.com/tarantool/tarantool-qa/issues/101
+      options: '--init --memory=7G --memory-swap=7G'
 
     steps:
       - uses: actions/checkout@v1

.travis.mk

@@ -325,6 +325,9 @@ deps_osx_github_actions:
 	pip3 install --force-reinstall -r test-run/requirements.txt
 
 build_osx:
+	# due swap disabling should be manualy configured need to
+	# control it's status
+	sysctl vm.swapusage
 	cmake . -DCMAKE_BUILD_TYPE=RelWithDebInfo -DENABLE_WERROR=ON ${CMAKE_EXTRA_PARAMS}
 	make -j
 
@@ -375,6 +378,9 @@ base_deps_osx_github_actions:
 # builddir used in this target - is a default build path from cmake
 # ExternalProject_Add()
 test_static_build_cmake_osx_no_deps:
+	# due swap disabling should be manualy configured need to
+	# control it's status
+	sysctl vm.swapusage
 	cd static-build && cmake -DCMAKE_TARANTOOL_ARGS="-DCMAKE_BUILD_TYPE=RelWithDebInfo;-DENABLE_WERROR=ON" . && \
 	make -j && ctest -V
 	# FIXME: Hell with SIP on OSX: Tarantool (and also LuaJIT)
@@ -406,6 +412,7 @@ deps_freebsd:
 		python27 py27-yaml py27-six py27-gevent
 
 build_freebsd:
+	if [ "$$(swapctl -l | wc -l)" != "1" ]; then sudo swapoff -a ; fi ; swapctl -l
 	cmake . -DCMAKE_BUILD_TYPE=RelWithDebInfo -DENABLE_WERROR=ON ${CMAKE_EXTRA_PARAMS}
 	gmake -j