Wip writeback throttling for cache tiering
This patch is to do write back throttling for cache tiering, which is similar to what the Linux kernel does for page cache write back. A paramter 'cache_target_dirty_high_ratio' (default 0.6) is introduced as the high speed flushing threshold, while leave the 'cache_target_dirty_ratio' (default 0.4) to represent the low speed threshold. The flush speed is controlled by limiting the parallelism of flushing. The maximum parallelism under low speed is half of the parallelism under high speed. If there is at least one PG such that the dirty ratio beyond the high threshold, full speed mode is entered; If there is no PG such that dirty ratio beyond the low threshold, idle mode is entered; In other cases, slow speed mode is entered.
Signed-off-by: Mingxin Liu <mingxinliu@ubuntukylin.com>
Reviewed-by: Li Wang <liwang@ubuntukylin.com>
Suggested-by: Nick Fisk <nick@fisk.me.uk>
Tested-by: Kefu Chai <kchai@redhat.com>
* use HOWTO_monitor_the_automated_tests_AKA_nightlies to explain the nightlies
* replace references to Serverity with Backport tracker
* add links to the backporter manual and the release page
* s/0.95/9.0.0/
* unify release names to be lowercase
* replace lifecycle with release cycle and end of life with retirement
* Prefer LTS or Long Term Stable over Long Term Support
Signed-off-by: Loic Dachary <ldachary@redhat.com>
When updating submodules, always checkout even if the HEAD is the
desired commit hash (update --force) to avoid the following:
* a directory gmock exists in hammer
* a submodule gmock replaces the directory gmock in master
* checkout master + submodule update : gmock/.git is created
* checkout hammer : the gmock directory still contains the .git from
master because it did not exist at the time and checkout won't
remove untracked directories
* checkout master + submodule update : git rev-parse HEAD is
at the desired commit although the content of the gmock directory
is from hammer
Signed-off-by: Loic Dachary <ldachary@redhat.com>
Document the high level view of the development workflows which are
otherwise implicit and non trivial to figure out.
Signed-off-by: Loic Dachary <ldachary@redhat.com>
When using :doc:`/dev/sepia` the page title is inlined. The modified
title is easier to include as part of a sensible sentence.
Signed-off-by: Loic Dachary <ldachary@redhat.com>
Encapsulate the compilation steps (install dependencies, autogen.sh,
configure, make check) in the run-make-check.sh script. Update the
developer documentation to point to this script instead of multiple
steps.
It is intended as a tool to help new developer make sure their patch is
sane, it focuses on efficiency (runs make check in parallel if possible)
and coverage (enables docker based tests if possible).
http://tracker.ceph.com/issues/10265Fixes: #10265
Signed-off-by: Loic Dachary <ldachary@redhat.com>
