From 9adacef70b97dc46f9295df3744cd954df19a67f Mon Sep 17 00:00:00 2001
From: Tom Englund <tomenglund26@gmail.com>
Date: Tue, 1 Jul 2025 11:32:17 +0200
Subject: [PATCH] buffer: check if buffer fd already readable (#10894)

check if buffer fd is already readable, to avoid a lot of unnecessery
systemcalls and churn.
---
 src/protocols/types/DMABuffer.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/protocols/types/DMABuffer.cpp b/src/protocols/types/DMABuffer.cpp
index 0f6334e68..b1621de7b 100644
--- a/src/protocols/types/DMABuffer.cpp
+++ b/src/protocols/types/DMABuffer.cpp
@@ -118,6 +118,9 @@ CFileDescriptor CDMABuffer::exportSyncFile() {
         if (fd == -1)
             continue;
 
+        if (CFileDescriptor::isReadable(fd))
+            continue;
+
         dma_buf_export_sync_file request{
             .flags = DMA_BUF_SYNC_READ,
             .fd    = -1,