common/options: Added bdev_discard_max_bytes and bdev_debug_discard_sleep options

Added a health warning mechanism to monitor the discard queue for potential overload
Emits a warning if the accumulated discarded bytes in the queue exceed the configured threshold
Introduced a debugging tool to simulate slow discard operations by adding a configurable delay

Fixes : https://tracker.ceph.com/issues/69082

Signed-off-by: Jaya Prakash <jayaprakash@ibm.com>

diff --git a/src/common/options/global.yaml.in b/src/common/options/global.yaml.in
index d9de4a8b1c4db431b7c1bb7980e6950e93201dab..8b95145badef8315fa32c14afbc63a03a9f08145 100644 (file)
--- a/src/common/options/global.yaml.in
+++ b/src/common/options/global.yaml.in
@@ -6748,6 +6748,27 @@ options:
   desc: A configurable number for stalled read warning to be appeared if number of stalled read occurence pass `bdev_stalled_read_warn_threshold` in `bdev_stalled_read_warn_lifetime` seconds
   default: 1
   with_legacy: true
+- name: bdev_discard_max_bytes
+  type: size
+  level: advanced
+  desc: Discard queue size in bytes that triggers health warning
+  long_desc: This parameter sets a threshold for the discard queue size (in bytes), triggering a health
+    warning when the queue exceeds the specified limit. This is particularly useful for devices with
+    slow discard operations, as a large backlog in the queue can block disk space that is marked as free
+    but not yet available for allocation, impacting system performance and storage efficiency.
+    `bdev_async_discard_max_pending` is measured in items, not bytes, so its value does not directly
+    correspond to the discard queue size in bytes.
+  default: 10_G
+  with_legacy: true
+  see_also:
+  - bdev_async_discard_max_pending
+- name: bdev_debug_discard_sleep
+  type: uint
+  level: dev
+  desc: A debugging tool to simulate slow discard operations by introducing a delay of
+    `bdev_debug_discard_sleep` milliseconds
+  default: 0
+  with_legacy: true
 - name: bluestore_cleaner_sleep_interval
   type: float
   level: advanced