linux-kernel - [PATCH] x86: Drop redundant memory-block sizing code

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Date:	Thu,  6 Nov 2014 12:50:14 +0800
From:	Daniel J Blueman <daniel@...ascale.com>
To:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>, Yinghai Lu <yinghai@...nel.org>
Cc:	Daniel J Blueman <daniel@...ascale.com>, x86@...nel.org,
	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
	Steffen Persvold <sp@...ascale.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Bjorn Helgaas <bhelgaas@...gle.com>
Subject: [PATCH] x86: Drop redundant memory-block sizing code

Drop the unused code from selecting a fixed memory block size of 2GB
on large-memory x86-64 systems.

Signed-off-by: Daniel J Blueman <daniel@...ascale.com>
---
 arch/x86/mm/init_64.c | 18 +-----------------
 1 file changed, 1 insertion(+), 17 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index ebca30f..09c0567 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1243,28 +1243,12 @@ int in_gate_area_no_mm(unsigned long addr)
 
 static unsigned long probe_memory_block_size(void)
 {
-	/* start from 2g */
-	unsigned long bz = 1UL<<31;
-
 	if (totalram_pages >= (64ULL << (30 - PAGE_SHIFT))) {
 		pr_info("Using 2GB memory block size for large-memory system\n");
 		return 2UL * 1024 * 1024 * 1024;
 	}
 
-	/* less than 64g installed */
-	if ((max_pfn << PAGE_SHIFT) < (16UL << 32))
-		return MIN_MEMORY_BLOCK_SIZE;
-
-	/* get the tail size */
-	while (bz > MIN_MEMORY_BLOCK_SIZE) {
-		if (!((max_pfn << PAGE_SHIFT) & (bz - 1)))
-			break;
-		bz >>= 1;
-	}
-
-	printk(KERN_DEBUG "memory block size : %ldMB\n", bz >> 20);
-
-	return bz;
+	return MIN_MEMORY_BLOCK_SIZE;
 }
 
 static unsigned long memory_block_size_probed;
-- 
1.9.1

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