From cee232b61c1e868e41e08392d9752283ab1a5853 Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Wed, 13 Oct 2021 16:41:11 +0100
Subject: [PATCH] [Minor] Add support for readahead(2) call if available

---
 CMakeLists.txt | 5 +++++
 config.h.in    | 1 +
 2 files changed, 6 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 816e403bd..118f8806f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -486,6 +486,11 @@ IF(CMAKE_SYSTEM_NAME STREQUAL "Linux")
 						  int main (int argc, char **argv) {
 							return ((int*)(&recvmmsg))[argc];
 						  }" HAVE_RECVMMSG)
+	CHECK_C_SOURCE_COMPILES ("#define _GNU_SOURCE
+						  #include <fcntl.h>
+						  int main (int argc, char **argv) {
+							return ((int*)(&readahead))[argc];
+						  }" HAVE_READAHEAD)
 ELSE()
 	CHECK_C_SOURCE_RUNS("
 	#include <sys/mman.h>
diff --git a/config.h.in b/config.h.in
index f83167463..65daa3e29 100644
--- a/config.h.in
+++ b/config.h.in
@@ -64,6 +64,7 @@
 #cmakedefine HAVE_PTHREAD_PROCESS_SHARED 1
 #cmakedefine HAVE_PWD_H          1
 #cmakedefine HAVE_RDTSC          1
+#cmakedefine HAVE_READAHEAD      1
 #cmakedefine HAVE_READPASSPHRASE_H  1
 #cmakedefine HAVE_RECVMMSG       1
 #cmakedefine HAVE_RUSAGE_SELF    1
-- 
2.39.5