From: "Jan Beulich" <jbeulich@novell.com>
To: <mingo@elte.hu>, <tglx@linutronix.de>, <hpa@zytor.com>
Cc: "Nick Piggin" <npiggin@suse.de>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] x86: make mm/gup.c more virtualization friendly
Date: Wed, 17 Sep 2008 16:48:17 +0100 [thread overview]
Message-ID: <48D142E1.76E4.0078.0@novell.com> (raw)
Since pte_flags() is much cheaper than pte_val() in some virtualized
environments (namely, Xen), use the former whereever possible.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Nick Piggin <npiggin@suse.de>
---
arch/x86/mm/gup.c | 10 +++++-----
include/asm-x86/pgtable.h | 2 +-
2 files changed, 6 insertions(+), 6 deletions(-)
--- linux-2.6.27-rc6/arch/x86/mm/gup.c 2008-08-21 14:37:29.000000000 +0200
+++ 2.6.27-rc6-x86-gup-virt/arch/x86/mm/gup.c 2008-09-02 13:33:42.000000000 +0200
@@ -82,7 +82,7 @@ static noinline int gup_pte_range(pmd_t
pte_t pte = gup_get_pte(ptep);
struct page *page;
- if ((pte_val(pte) & (mask | _PAGE_SPECIAL)) != mask) {
+ if ((pte_flags(pte) & (mask | _PAGE_SPECIAL)) != mask) {
pte_unmap(ptep);
return 0;
}
@@ -116,10 +116,10 @@ static noinline int gup_huge_pmd(pmd_t p
mask = _PAGE_PRESENT|_PAGE_USER;
if (write)
mask |= _PAGE_RW;
- if ((pte_val(pte) & mask) != mask)
+ if ((pte_flags(pte) & mask) != mask)
return 0;
/* hugepages are never "special" */
- VM_BUG_ON(pte_val(pte) & _PAGE_SPECIAL);
+ VM_BUG_ON(pte_flags(pte) & _PAGE_SPECIAL);
VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
refs = 0;
@@ -173,10 +173,10 @@ static noinline int gup_huge_pud(pud_t p
mask = _PAGE_PRESENT|_PAGE_USER;
if (write)
mask |= _PAGE_RW;
- if ((pte_val(pte) & mask) != mask)
+ if ((pte_flags(pte) & mask) != mask)
return 0;
/* hugepages are never "special" */
- VM_BUG_ON(pte_val(pte) & _PAGE_SPECIAL);
+ VM_BUG_ON(pte_flags(pte) & _PAGE_SPECIAL);
VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
refs = 0;
--- linux-2.6.27-rc6/include/asm-x86/pgtable.h 2008-08-21 14:37:34.000000000 +0200
+++ 2.6.27-rc6-x86-gup-virt/include/asm-x86/pgtable.h 2008-09-02 13:31:50.000000000 +0200
@@ -183,7 +183,7 @@ static inline int pte_exec(pte_t pte)
static inline int pte_special(pte_t pte)
{
- return pte_val(pte) & _PAGE_SPECIAL;
+ return pte_flags(pte) & _PAGE_SPECIAL;
}
static inline int pmd_large(pmd_t pte)
next reply other threads:[~2008-09-17 15:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-17 15:48 Jan Beulich [this message]
2008-09-18 10:15 ` [PATCH] x86: make mm/gup.c more virtualization friendly Ingo Molnar
2008-09-23 4:42 ` Nick Piggin
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