LU-16019 llite: fully disable readahead in kernel I/O path

[fs/lustre-release.git] / lustre / autoconf / lustre-core.m4

diff --git a/lustre/autoconf/lustre-core.m4 b/lustre/autoconf/lustre-core.m4
index bcd0294..9adaac6 100644 (file)
--- a/lustre/autoconf/lustre-core.m4
+++ b/lustre/autoconf/lustre-core.m4
@@ -1943,6 +1943,27 @@ posix_acl_update_mode, [
 ]) # LC_POSIX_ACL_UPDATE_MODE
 
 #
+# LC_HAVE_BDI_IO_PAGES
+#
+# Kernel version 4.9 commit 9491ae4aade6814afcfa67f4eb3e3342c2b39750
+# mm: don't cap request size based on read-ahead setting
+# This patch introduces a bdi hint, io_pages.
+#
+AC_DEFUN([LC_HAVE_BDI_IO_PAGES], [
+LB_CHECK_COMPILE([if 'struct backing_dev_info' has 'io_pages' field],
+bdi_has_io_pages, [
+       #include <linux/backing-dev.h>
+],[
+       struct backing_dev_info info;
+
+       info.io_pages = 0;
+],[
+       AC_DEFINE(HAVE_BDI_IO_PAGES, 1,
+               [backing_dev_info has io_pages])
+])
+]) # LC_HAVE_BDI_IO_PAGES
+
+#
 # LC_IOP_GENERIC_READLINK
 #
 # Kernel version 4.10 commit dfeef68862edd7d4bafe68ef7aeb5f658ef24bb5
@@ -2822,6 +2843,7 @@ AC_DEFUN([LC_PROG_LINUX], [
        LC_GROUP_INFO_GID
        LC_VFS_SETXATTR
        LC_POSIX_ACL_UPDATE_MODE
+       LC_HAVE_BDI_IO_PAGES
 
        # 4.10
        LC_IOP_GENERIC_READLINK