[PATCH v2 1/2] lib/raid: use kvmalloc() in calibrate_xor_blocks()

From: Mike Rapoport (Microsoft)

Date: Tue May 26 2026 - 08:56:23 EST


The xor benchmark allocates an order 2 (4 pages) scratch buffer that is
used purely as a CPU-only XOR working area.

This buffer does not need to be physically contiguous and can be
allocated with kvmalloc().

Replace __get_free_pages() call with kvmalloc().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@xxxxxxxxxx
Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
---
lib/raid/xor/xor-core.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/raid/xor/xor-core.c b/lib/raid/xor/xor-core.c
index bd4e6e434418..9f90620617cd 100644
--- a/lib/raid/xor/xor-core.c
+++ b/lib/raid/xor/xor-core.c
@@ -8,6 +8,7 @@

#include <linux/module.h>
#include <linux/gfp.h>
+#include <linux/slab.h>
#include <linux/raid/xor.h>
#include <linux/jiffies.h>
#include <linux/preempt.h>
@@ -114,7 +115,7 @@ static int __init calibrate_xor_blocks(void)
if (forced_template)
return 0;

- b1 = (void *) __get_free_pages(GFP_KERNEL, 2);
+ b1 = kvmalloc(PAGE_SIZE * 4, GFP_KERNEL);
if (!b1) {
pr_warn("xor: Yikes! No memory available.\n");
return -ENOMEM;
@@ -132,7 +133,7 @@ static int __init calibrate_xor_blocks(void)
pr_info("xor: using function: %s (%d MB/sec)\n",
fastest->name, fastest->speed);

- free_pages((unsigned long)b1, 2);
+ kvfree(b1);
return 0;
}


--
2.53.0