From bf6b98befd3632bcdda444491dfedc0110d0e091 Mon Sep 17 00:00:00 2001 From: tanchangzhi <544463199@qq.com> Date: Tue, 17 Oct 2023 16:48:51 +0800 Subject: [PATCH] doc: Update mClock QOS documentation to discard osd_mclock_cost_per_* The cost parameters (osd_mclock_cost_per_*) have been removed. The cost of an operation is now determined using the random IOPS and maximum sequential bandwidth capability of the OSD's underlying device. Fixes: https://tracker.ceph.com/issues/58529 Signed-off-by: tanchangzhi <544463199@qq.com> (cherry picked from commit a7502cb5125dda8d052dc3991ed5d7013606aca2) --- .../osd_internals/mclock_wpq_cmp_study.rst | 23 ------------------- 1 file changed, 23 deletions(-) diff --git a/doc/dev/osd_internals/mclock_wpq_cmp_study.rst b/doc/dev/osd_internals/mclock_wpq_cmp_study.rst index 88e350c862f1d..31ad184098eab 100644 --- a/doc/dev/osd_internals/mclock_wpq_cmp_study.rst +++ b/doc/dev/osd_internals/mclock_wpq_cmp_study.rst @@ -114,29 +114,6 @@ baseline throughput for each device type was determined: 256 KiB. For HDDs, it was 40MiB. The above throughput was obtained by running 4 KiB random writes at a queue depth of 64 for 300 secs. -Factoring I/O Cost in mClock -============================ - -The services using mClock have a cost associated with them. The cost can be -different for each service type. The mClock scheduler factors in the cost -during calculations for parameters like *reservation*, *weight* and *limit*. -The calculations determine when the next op for the service type can be -dequeued from the operation queue. In general, the higher the cost, the longer -an op remains in the operation queue. - -A cost modeling study was performed to determine the cost per I/O and the cost -per byte for SSD and HDD device types. The following cost specific options are -used under the hood by mClock, - -- :confval:`osd_mclock_cost_per_io_usec` -- :confval:`osd_mclock_cost_per_io_usec_hdd` -- :confval:`osd_mclock_cost_per_io_usec_ssd` -- :confval:`osd_mclock_cost_per_byte_usec` -- :confval:`osd_mclock_cost_per_byte_usec_hdd` -- :confval:`osd_mclock_cost_per_byte_usec_ssd` - -See :doc:`/rados/configuration/mclock-config-ref` for more details. - MClock Profile Allocations ========================== -- 2.39.5