The variable dmirror_zero_page is unused in the HMM self test driver
which was probably intended to demonstrate how a driver could use
migrate_vma_setup() to share a single read-only device private zero page
similar to how the CPU does. However, this isn't needed for the self tests
so remove it.
Signed-off-by: Ralph Campbell <[email protected]>
---
This applies to linux-mm and is intended for Andrew Morton's git tree.
lib/test_hmm.c | 14 --------------
1 file changed, 14 deletions(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index e3065d6123f0..c8133f50160b 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -36,7 +36,6 @@
static const struct dev_pagemap_ops dmirror_devmem_ops;
static const struct mmu_interval_notifier_ops dmirror_min_ops;
static dev_t dmirror_dev;
-static struct page *dmirror_zero_page;
struct dmirror_device;
@@ -1127,17 +1126,6 @@ static int __init hmm_dmirror_init(void)
goto err_chrdev;
}
- /*
- * Allocate a zero page to simulate a reserved page of device private
- * memory which is always zero. The zero_pfn page isn't used just to
- * make the code here simpler (i.e., we need a struct page for it).
- */
- dmirror_zero_page = alloc_page(GFP_HIGHUSER | __GFP_ZERO);
- if (!dmirror_zero_page) {
- ret = -ENOMEM;
- goto err_chrdev;
- }
-
pr_info("HMM test module loaded. This is only for testing HMM.\n");
return 0;
@@ -1153,8 +1141,6 @@ static void __exit hmm_dmirror_exit(void)
{
int id;
- if (dmirror_zero_page)
- __free_page(dmirror_zero_page);
for (id = 0; id < DMIRROR_NDEVICES; id++)
dmirror_device_remove(dmirror_devices + id);
unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES);
--
2.20.1