[PATCH 06/12] swiotlb-xen: limit init retries

From: Jan Beulich
Date: Tue Sep 07 2021 - 08:06:45 EST


Due to the use of max(1024, ...) there's no point retrying (and issuing
bogus log messages) when the number of slabs is already no larger than
this minimum value.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -207,7 +207,7 @@ retry:
swiotlb_set_max_segment(PAGE_SIZE);
return 0;
error:
- if (repeat--) {
+ if (nslabs > 1024 && repeat--) {
/* Min is 2MB */
nslabs = max(1024UL, ALIGN(nslabs >> 1, IO_TLB_SEGSIZE));
bytes = nslabs << IO_TLB_SHIFT;
@@ -243,7 +243,7 @@ retry:
rc = xen_swiotlb_fixup(start, nslabs);
if (rc) {
memblock_free(__pa(start), PAGE_ALIGN(bytes));
- if (repeat--) {
+ if (nslabs > 1024 && repeat--) {
/* Min is 2MB */
nslabs = max(1024UL, ALIGN(nslabs >> 1, IO_TLB_SEGSIZE));
bytes = nslabs << IO_TLB_SHIFT;