From 0689be6c0e497edee0ca6c391c2b2242c18babda Mon Sep 17 00:00:00 2001
From: Saleel Kudchadker <Saleel.Kudchadker@amd.com>
Date: Fri, 18 Mar 2022 11:28:55 -0700
Subject: [PATCH] SWDEV-328349 - Rate limit hostcall listener

Update timeout for hostcall wait for signal. If the timeout is small it
checks frequent enough to affect performance for certain applications
which may be CPU bound.

Change-Id: I0a879559e4ad111b09a994a5b82a6faf6e4fea3f


[ROCm/clr commit: 9292abb2d8398eed32b1ba16259e6c636ac9edb7]
---
 projects/clr/rocclr/device/devhostcall.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/projects/clr/rocclr/device/devhostcall.cpp b/projects/clr/rocclr/device/devhostcall.cpp
index afd1cdf23d..c87ad199ae 100644
--- a/projects/clr/rocclr/device/devhostcall.cpp
+++ b/projects/clr/rocclr/device/devhostcall.cpp
@@ -270,17 +270,25 @@ class HostcallListener {
 
 HostcallListener* hostcallListener = nullptr;
 amd::Monitor listenerLock("Hostcall listener lock");
+constexpr static uint64_t kTimeoutFloor = K * K * 4;
+constexpr static uint64_t kTimeoutCeil = K * K * 16;
 
 void HostcallListener::consumePackets() {
-  uint64_t timeout = 1024 * 1024;
+  uint64_t timeout = kTimeoutFloor;
   uint64_t signal_value = SIGNAL_INIT;
   while (true) {
     while (true) {
       uint64_t new_value = doorbell_->Wait(signal_value, device::Signal::Condition::Ne, timeout);
       if (new_value != signal_value) {
         signal_value = new_value;
+        // Reduce the timeout for quicker processing
+        timeout = timeout >> 0x1;
+        timeout = std::max(kTimeoutFloor, timeout);
         break;
       }
+      // Increase the timeout since we dont need to check as frequently
+      timeout = timeout << 0x1;
+      timeout = std::min(kTimeoutCeil, timeout);
     }
 
     if (signal_value == SIGNAL_DONE) {