From: Mohit Agrawal <moagrawa@redhat.com>
Date: Thu, 23 Jan 2025 14:34:25 +0000 (+0530)
Subject: crimson: Provide an options to configure several seastar parameters
X-Git-Tag: v20.0.0~3^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=ba7cc3b52602d6006e69a69f1e2165d9999ed35a;p=ceph.git

crimson: Provide an options to configure several seastar parameters

Implement a new mechanism to introduce a new seastar parameter in
future and add options to configure parameters like task_quota_ms,
io_latency_goal_ms and idle_poll_time_us.

Fixes: https://tracker.ceph.com/issues/69595
Signed-off-by: Mohit Agrawal <moagrawa@redhat.com>
---

diff --git a/src/common/options/crimson.yaml.in b/src/common/options/crimson.yaml.in
index 132a4a09e89..c8b4adacf76 100644
--- a/src/common/options/crimson.yaml.in
+++ b/src/common/options/crimson.yaml.in
@@ -51,6 +51,35 @@ options:
   - startup
   min: 0
   max: 32
+- name: crimson_reactor_task_quota_ms
+  type: float
+  level: advanced
+  default: 0.5
+  desc: The maximum time (ms) Seastar reactors will wait between polls.
+  long_desc: The maximum time (ms) Seastar reactors will wait between polls.
+             Shorter time between pools will result in larger CPU utilization.
+  flags:
+  - startup
+- name: crimson_reactor_idle_poll_time_us
+  type: uint
+  level: advanced
+  default: 200
+  desc: Seastar's reactor idle polling time (ms) before going back to sleep.
+  long_desc: Seastar's reactor idle polling time (ms) before going back to sleep.
+             Longer reactor poll time will result in larger CPU utilization.
+  flags:
+  - startup
+- name: crimson_reactor_io_latency_goal_ms
+  type: float
+  level: advanced
+  default: 0
+  desc: The maximum time (ms) Seastar's reactor IO operations must take.
+        If not set(0 mean not set), defaults to 1.5 * crimson_reactor_task_quota_ms
+  long_desc: The maximum time (ms) Seastar's reactor IO operations must take.
+             If not set, defaults to 1.5 * crimson_reactor_task_quota_ms.
+             Increasing this value will allow more IO requests to be dispatched concurrently.
+  flags:
+  - startup
 - name: crimson_osd_stat_interval
   type: int
   level: advanced
diff --git a/src/crimson/osd/main_config_bootstrap_helpers.cc b/src/crimson/osd/main_config_bootstrap_helpers.cc
index e4920eb870f..a76bce3d16c 100644
--- a/src/crimson/osd/main_config_bootstrap_helpers.cc
+++ b/src/crimson/osd/main_config_bootstrap_helpers.cc
@@ -84,6 +84,41 @@ seastar::future<> populate_config_from_mon()
   });
 }
 
+struct SeastarOption {
+  std::string option_name;  // Command-line option name
+  std::string config_key;   // Configuration key
+  Option::type_t value_type ;   // Type of configuration value
+};
+
+// Define a list of Seastar options
+const std::vector<SeastarOption> seastar_options = {
+  {"--task-quota-ms", "crimson_reactor_task_quota_ms", Option::TYPE_FLOAT},
+  {"--io-latency-goal-ms", "crimson_reactor_io_latency_goal_ms", Option::TYPE_FLOAT},
+  {"--idle-poll-time-us", "crimson_reactor_idle_poll_time_us", Option::TYPE_UINT}
+};
+
+// Function to get the option value as a string
+std::optional<std::string> get_option_value(const SeastarOption& option) {
+  switch (option.value_type) {
+    case Option::TYPE_FLOAT: {
+      if (auto value = crimson::common::get_conf<double>(option.config_key)) {
+        return std::to_string(value);
+      }
+      break;
+    }
+    case Option::TYPE_UINT: {
+      if (auto value = crimson::common::get_conf<uint64_t>(option.config_key)) {
+        return std::to_string(value);
+      }
+      break;
+    }
+    default:
+      logger().warn("get_option_value --option_name {} encountered unknown type", option.config_key);
+      return std::nullopt;
+  }
+  return std::nullopt;
+}
+
 static tl::expected<early_config_t, int>
 _get_early_config(int argc, const char *argv[])
 {
@@ -143,6 +178,14 @@ _get_early_config(int argc, const char *argv[])
 	  std::begin(early_args),
 	  std::end(early_args));
 
+        for (const auto& option : seastar_options) {
+          auto option_value = get_option_value(option);
+          if (option_value) {
+            logger().info("Configure option_name {} with value : {}", option.config_key, option_value);
+            ret.early_args.emplace_back(option.option_name);
+            ret.early_args.emplace_back(*option_value);
+          }
+        }
 	if (auto found = std::find_if(
 	      std::begin(early_args),
 	      std::end(early_args),