[PATCH v1 7/9] arm64: kdump: No need to mark crashkernel pages manually PG_reserved

David Hildenbrand
2018-12-14T11:10:12Z

The crashkernel is reserved via memblock_reserve(). memblock_free_all()
will call free_low_memory_core_early(), which will go over all reserved
memblocks, marking the pages as PG_reserved.

So manually marking pages as PG_reserved is not necessary, they are
already in the desired state (otherwise they would have been handed over
to the buddy as free pages and bad things would happen).

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Greg Hackmann <ghackmann@android.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kristina Martsenko <kristina.martsenko@arm.com>
Cc: CHANDAN VN <chandan.vn@samsung.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/arm64/kernel/machine_kexec.c | 2 +-
arch/arm64/mm/init.c | 27 ---------------------------
2 files changed, 1 insertion(+), 28 deletions(-)

diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index 6f0587b5e941..66b5d697d943 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -321,7 +321,7 @@ void crash_post_resume(void)
* but does not hold any data of loaded kernel image.
*
* Note that all the pages in crash dump kernel memory have been initially
- * marked as Reserved in kexec_reserve_crashkres_pages().
+ * marked as Reserved as memory was allocated via memblock_reserve().
*
* In hibernation, the pages which are Reserved and yet "nosave" are excluded
* from the hibernation iamge. crash_is_nosave() does thich check for crash
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index a8f2e4792ef9..9dcfa809b7ab 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -118,35 +118,10 @@ static void __init reserve_crashkernel(void)
crashk_res.start = crash_base;
crashk_res.end = crash_base + crash_size - 1;
}
-
-static void __init kexec_reserve_crashkres_pages(void)
-{
-#ifdef CONFIG_HIBERNATION
- phys_addr_t addr;
- struct page *page;
-
- if (!crashk_res.end)
- return;
-
- /*
- * To reduce the size of hibernation image, all the pages are
- * marked as Reserved initially.
- */
- for (addr = crashk_res.start; addr < (crashk_res.end + 1);
- addr += PAGE_SIZE) {
- page = phys_to_page(addr);
- SetPageReserved(page);
- }
-#endif
-}
#else
static void __init reserve_crashkernel(void)
{
}
-
-static void __init kexec_reserve_crashkres_pages(void)
-{
-}
#endif /* CONFIG_KEXEC_CORE */

#ifdef CONFIG_CRASH_DUMP
@@ -586,8 +561,6 @@ void __init mem_init(void)
/* this will put all unused low memory onto the freelists */
memblock_free_all();

- kexec_reserve_crashkres_pages();
-
mem_init_print_info(NULL);

/*