linux-kernel - [PATCHv2 1/7] x86/mm: concentrate the code to memblock allocator enabled

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Date:   Fri, 11 Jan 2019 13:12:51 +0800
From:   Pingfan Liu <kernelfans@...il.com>
To:     linux-kernel@...r.kernel.org
Cc:     Pingfan Liu <kernelfans@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Len Brown <lenb@...nel.org>, Yinghai Lu <yinghai@...nel.org>,
        Tejun Heo <tj@...nel.org>, Chao Fan <fanc.fnst@...fujitsu.com>,
        Baoquan He <bhe@...hat.com>, Juergen Gross <jgross@...e.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Mike Rapoport <rppt@...ux.vnet.ibm.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Michal Hocko <mhocko@...e.com>, x86@...nel.org,
        linux-acpi@...r.kernel.org, linux-mm@...ck.org
Subject: [PATCHv2 1/7] x86/mm: concentrate the code to memblock allocator enabled

This patch identifies the point where memblock alloc start. It has no
functional.

Signed-off-by: Pingfan Liu <kernelfans@...il.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: "H. Peter Anvin" <hpa@...or.com>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: Len Brown <lenb@...nel.org>
Cc: Yinghai Lu <yinghai@...nel.org>
Cc: Tejun Heo <tj@...nel.org>
Cc: Chao Fan <fanc.fnst@...fujitsu.com>
Cc: Baoquan He <bhe@...hat.com>
Cc: Juergen Gross <jgross@...e.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Mike Rapoport <rppt@...ux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@...e.cz>
Cc: Michal Hocko <mhocko@...e.com>
Cc: x86@...nel.org
Cc: linux-acpi@...r.kernel.org
Cc: linux-mm@...ck.org
---
 arch/x86/kernel/setup.c | 54 ++++++++++++++++++++++++-------------------------
 1 file changed, 26 insertions(+), 28 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index d494b9b..ac432ae 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -962,29 +962,6 @@ void __init setup_arch(char **cmdline_p)
 
 	if (efi_enabled(EFI_BOOT))
 		efi_memblock_x86_reserve_range();
-#ifdef CONFIG_MEMORY_HOTPLUG
-	/*
-	 * Memory used by the kernel cannot be hot-removed because Linux
-	 * cannot migrate the kernel pages. When memory hotplug is
-	 * enabled, we should prevent memblock from allocating memory
-	 * for the kernel.
-	 *
-	 * ACPI SRAT records all hotpluggable memory ranges. But before
-	 * SRAT is parsed, we don't know about it.
-	 *
-	 * The kernel image is loaded into memory at very early time. We
-	 * cannot prevent this anyway. So on NUMA system, we set any
-	 * node the kernel resides in as un-hotpluggable.
-	 *
-	 * Since on modern servers, one node could have double-digit
-	 * gigabytes memory, we can assume the memory around the kernel
-	 * image is also un-hotpluggable. So before SRAT is parsed, just
-	 * allocate memory near the kernel image to try the best to keep
-	 * the kernel away from hotpluggable memory.
-	 */
-	if (movable_node_is_enabled())
-		memblock_set_bottom_up(true);
-#endif
 
 	x86_report_nx();
 
@@ -1096,9 +1073,6 @@ void __init setup_arch(char **cmdline_p)
 
 	cleanup_highmap();
 
-	memblock_set_current_limit(ISA_END_ADDRESS);
-	e820__memblock_setup();
-
 	reserve_bios_regions();
 
 	if (efi_enabled(EFI_MEMMAP)) {
@@ -1113,6 +1087,8 @@ void __init setup_arch(char **cmdline_p)
 		efi_reserve_boot_services();
 	}
 
+	memblock_set_current_limit(0, ISA_END_ADDRESS, false);
+	e820__memblock_setup();
 	/* preallocate 4k for mptable mpc */
 	e820__memblock_alloc_reserved_mpc_new();
 
@@ -1130,7 +1106,31 @@ void __init setup_arch(char **cmdline_p)
 	trim_platform_memory_ranges();
 	trim_low_memory_range();
 
+#ifdef CONFIG_MEMORY_HOTPLUG
+	/*
+	 * Memory used by the kernel cannot be hot-removed because Linux
+	 * cannot migrate the kernel pages. When memory hotplug is
+	 * enabled, we should prevent memblock from allocating memory
+	 * for the kernel.
+	 *
+	 * ACPI SRAT records all hotpluggable memory ranges. But before
+	 * SRAT is parsed, we don't know about it.
+	 *
+	 * The kernel image is loaded into memory at very early time. We
+	 * cannot prevent this anyway. So on NUMA system, we set any
+	 * node the kernel resides in as un-hotpluggable.
+	 *
+	 * Since on modern servers, one node could have double-digit
+	 * gigabytes memory, we can assume the memory around the kernel
+	 * image is also un-hotpluggable. So before SRAT is parsed, just
+	 * allocate memory near the kernel image to try the best to keep
+	 * the kernel away from hotpluggable memory.
+	 */
+	if (movable_node_is_enabled())
+		memblock_set_bottom_up(true);
+#endif
 	init_mem_mapping();
+	memblock_set_current_limit(get_max_mapped());
 
 	idt_setup_early_pf();
 
@@ -1145,8 +1145,6 @@ void __init setup_arch(char **cmdline_p)
 	 */
 	mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE;
 
-	memblock_set_current_limit(get_max_mapped());
-
 	/*
 	 * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
 	 */
-- 
2.7.4