From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 3 Jul 2009 08:44:34 -0500
Subject: mm/scatterlist: Do not disable irqs on RT
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.18/older/patches-4.18.7-rt5.tar.xz

For -RT it is enough to keep pagefault disabled (which is currently handled by
kmap_atomic()).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 lib/scatterlist.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -776,7 +776,7 @@ void sg_miter_stop(struct sg_mapping_ite
 			flush_kernel_dcache_page(miter->page);
 
 		if (miter->__flags & SG_MITER_ATOMIC) {
-			WARN_ON_ONCE(preemptible());
+			WARN_ON_ONCE(!pagefault_disabled());
 			kunmap_atomic(miter->addr);
 		} else
 			kunmap(miter->page);