From c6f74709b9493c3d6456507f566c5c52c9f9fc5a Mon Sep 17 00:00:00 2001
From: Genevieve Helsel <helsel@fb.com>
Date: Wed, 30 Jun 2021 14:56:26 -0700
Subject: [PATCH] store file access logging percentage as a denominator

Reviewed By: chadaustin

Differential Revision: D29475156

fbshipit-source-id: efe207f1a4a09d4a718b9392294dbb7e91a2b98f
---
 eden/fs/config/EdenConfig.h | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/eden/fs/config/EdenConfig.h b/eden/fs/config/EdenConfig.h
index 44f3905605..861a278b08 100644
--- a/eden/fs/config/EdenConfig.h
+++ b/eden/fs/config/EdenConfig.h
@@ -615,13 +615,15 @@ class EdenConfig : private ConfigSettingManager {
       this};
 
   /**
-   * A number from 0 - 100 to determine how often we should log file access
+   * A number from 0 - x to determine how often we should log file access
    * events. This is currectly agnostic to the type of file access. If this
-   * is not at 100, we will not log filenames and we will only log directory
-   * paths
+   * is not at 100%, we will not log filenames and we will only log directory
+   * paths. In the following equation, 1/x = percentage, x is this variable.
+   * For 50% rollout, 1/x = .5, so x = 2, so this would be set to 2. 0
+   * indicates that the feature is off.
    */
-  ConfigSetting<uint32_t> logFileAccessesPercentage{
-      "prefetch-profiles:file-access-logging-percentage",
+  ConfigSetting<uint32_t> logFileAccessesSamplingDenominator{
+      "prefetch-profiles:file-access-logging-sampling-denominator",
       0,
       this};