diff options
author | Michel Lespinasse <walken@google.com> | 2012-12-12 00:01:56 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-12 01:22:25 (GMT) |
commit | 7d025059650f1c41a427173789ac14b74212b361 (patch) | |
tree | 5905f22f0ff11f96850d7caeec90c8ae898c6d47 | |
parent | f99024729e689f5de4534fde5400e3b035f068de (diff) | |
download | linux-7d025059650f1c41a427173789ac14b74212b361.tar.xz |
mm: fix cache coloring on x86_64 architecture
Fix the x86-64 cache alignment code to take pgoff into account. Use the
x86 and MIPS cache alignment code as the basis for a generic cache
alignment function.
The old x86 code will always align the mmap to aliasing boundaries,
even if the program mmaps the file with a non-zero pgoff.
If program A mmaps the file with pgoff 0, and program B mmaps the file
with pgoff 1. The old code would align the mmaps, resulting in misaligned
pages:
A: 0123
B: 123
After this patch, they are aligned so the pages line up:
A: 0123
B: 123
Proposed by Rik van Riel.
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | arch/x86/kernel/sys_x86_64.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index f00d006..97ef74b 100644 --- a/arch/x86/kernel/sys_x86_64.c +++ b/arch/x86/kernel/sys_x86_64.c @@ -136,7 +136,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, info.low_limit = begin; info.high_limit = end; info.align_mask = filp ? get_align_mask() : 0; - info.align_offset = 0; + info.align_offset = pgoff << PAGE_SHIFT; return vm_unmapped_area(&info); } @@ -175,7 +175,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, info.low_limit = PAGE_SIZE; info.high_limit = mm->mmap_base; info.align_mask = filp ? get_align_mask() : 0; - info.align_offset = 0; + info.align_offset = pgoff << PAGE_SHIFT; addr = vm_unmapped_area(&info); if (!(addr & ~PAGE_MASK)) return addr; |