From: Dean Roe <roe@sgi.com>
To: linux-ia64@vger.kernel.org
Subject: [PATCH] - Make pfn_valid more precise for SGI Altix systems
Date: Wed, 09 Nov 2005 20:25:06 +0000 [thread overview]
Message-ID: <20051109202506.GA4152@sgi.com> (raw)
A single SGI Altix system can be divided into multiple partitions,
each running their own instance of the Linux kernel. pfn_valid()
is currently not optimal for any but the first partition, since it
does not compare the pfn with min_low_pfn before calling the more
costly ia64_pfn_valid().
Signed-off-by: Dean Roe <roe@sgi.com>
Index: linux-ia64-test/arch/ia64/kernel/ia64_ksyms.c
=================================--- linux-ia64-test.orig/arch/ia64/kernel/ia64_ksyms.c 2005-11-09 14:10:17.473464250 -0600
+++ linux-ia64-test/arch/ia64/kernel/ia64_ksyms.c 2005-11-09 14:10:50.800226042 -0600
@@ -42,6 +42,7 @@
#ifdef CONFIG_VIRTUAL_MEM_MAP
#include <linux/bootmem.h>
+EXPORT_SYMBOL(min_low_pfn); /* defined by bootmem.c, but not exported by generic code */
EXPORT_SYMBOL(max_low_pfn); /* defined by bootmem.c, but not exported by generic code */
#endif
Index: linux-ia64-test/include/asm-ia64/page.h
=================================--- linux-ia64-test.orig/include/asm-ia64/page.h 2005-11-09 14:10:17.484205369 -0600
+++ linux-ia64-test/include/asm-ia64/page.h 2005-11-09 14:10:50.803155438 -0600
@@ -112,8 +112,9 @@
# define pfn_to_page(pfn) (mem_map + (pfn))
#elif defined(CONFIG_DISCONTIGMEM)
extern struct page *vmem_map;
+extern unsigned long min_low_pfn;
extern unsigned long max_low_pfn;
-# define pfn_valid(pfn) (((pfn) < max_low_pfn) && ia64_pfn_valid(pfn))
+# define pfn_valid(pfn) (((pfn) >= min_low_pfn) && ((pfn) < max_low_pfn) && ia64_pfn_valid(pfn))
# define page_to_pfn(page) ((unsigned long) (page - vmem_map))
# define pfn_to_page(pfn) (vmem_map + (pfn))
#endif
next reply other threads:[~2005-11-09 20:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-11-09 20:25 Dean Roe [this message]
2005-11-09 23:24 ` [PATCH] - Make pfn_valid more precise for SGI Altix systems Luck, Tony
2005-11-09 23:34 ` Luck, Tony
2005-11-10 16:19 ` Dean Roe
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