memblock: Disable mirror feature if kernelcore is not specified

If system have some mirrored memory and mirrored feature is not specified
in boot parameter, the basic mirrored feature will be enabled and this will
lead to the following situations:

- memblock memory allocation prefers mirrored region. This may have some
  unexpected influence on numa affinity.

- contiguous memory will be split into several parts if parts of them
  is mirrored memory via memblock_mark_mirror().

To fix this, variable mirrored_kernelcore will be checked in
memblock_mark_mirror(). Mark mirrored memory with flag MEMBLOCK_MIRROR iff
kernelcore=mirror is added in the kernel parameters.

Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220614092156.1972846-6-mawupeng1@huawei.com
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/mm/internal.h b/mm/internal.h
index c0f8fbe0445b5f1704c41e2a4f2b664456b9768f..ddd2d6a46f1b7cb96d6ca7ae4d28b057b474ac1a 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -861,4 +861,6 @@ struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
 
 DECLARE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
 
+extern bool mirrored_kernelcore;
+
 #endif /* __MM_INTERNAL_H */

diff --git a/mm/memblock.c b/mm/memblock.c
index b1d2a0009733b3352b86f2aa223d4e2a78948f88..a9f18b988b7f6e20057d8157bd780551f717924f 100644 (file)
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -924,6 +924,9 @@ int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
  */
 int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
 {
+       if (!mirrored_kernelcore)
+               return 0;
+
        system_has_some_mirror = true;
 
        return memblock_setclr_flag(base, size, 1, MEMBLOCK_MIRROR);

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e008a3df0485c79ac24ef31b4407dd5921a9649a..10dc35ec7479514f4464dd81fcf6c9a94390ef58 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -356,7 +356,7 @@ static unsigned long required_kernelcore_percent __initdata;
 static unsigned long required_movablecore __initdata;
 static unsigned long required_movablecore_percent __initdata;
 static unsigned long zone_movable_pfn[MAX_NUMNODES] __initdata;
-static bool mirrored_kernelcore __meminitdata;
+bool mirrored_kernelcore __initdata_memblock;
 
 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
 int movable_zone;