--- arch/x86/kernel/crash_dump_64.c

+++ arch/x86/kernel/crash_dump_64.c

@@ -34,7 +34,7 @@ ssize_t copy_oldmem_page(unsigned long p

if (!csize)

return 0;

- vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);

+ vaddr = ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);

if (!vaddr)

return -ENOMEM;

@@ -46,6 +46,7 @@ ssize_t copy_oldmem_page(unsigned long p

} else

memcpy(buf, vaddr + offset, csize);

+ set_iounmap_nonlazy();

iounmap(vaddr);

return csize;

}