From: Michel Lespinasse <walken@google.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>, Hugh Dickins <hughd@google.com>,
linux-kernel@vger.kernel.org,
Russell King <linux@arm.linux.org.uk>,
Ralf Baechle <ralf@linux-mips.org>,
Paul Mundt <lethal@linux-sh.org>,
"David S. Miller" <davem@davemloft.net>,
Chris Metcalf <cmetcalf@tilera.com>,
x86@kernel.org, William Irwin <wli@holomorphy.com>
Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
linux-mips@linux-mips.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org, Rik van Riel <riel@surriel.com>
Subject: [PATCH 04/16] mm: rearrange vm_area_struct for fewer cache misses
Date: Mon, 5 Nov 2012 14:47:01 -0800 [thread overview]
Message-ID: <1352155633-8648-5-git-send-email-walken@google.com> (raw)
In-Reply-To: <1352155633-8648-1-git-send-email-walken@google.com>
From: Rik van Riel <riel@surriel.com>
The kernel walks the VMA rbtree in various places, including
the page fault path. However, the vm_rb node spanned two
cache lines, on 64 bit systems with 64 byte cache lines (most
x86 systems).
Rearrange vm_area_struct a little, so all the information we
need to do a VMA tree walk is in the first cache line.
Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
---
include/linux/mm_types.h | 12 ++++++++----
1 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 94fa52b28ee8..528da4abf8ee 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -224,7 +224,8 @@ struct vm_region {
* library, the executable area etc).
*/
struct vm_area_struct {
- struct mm_struct * vm_mm; /* The address space we belong to. */
+ /* The first cache line has the info for VMA tree walking. */
+
unsigned long vm_start; /* Our start address within vm_mm. */
unsigned long vm_end; /* The first byte after our end address
within vm_mm. */
@@ -232,9 +233,6 @@ struct vm_area_struct {
/* linked list of VM areas per task, sorted by address */
struct vm_area_struct *vm_next, *vm_prev;
- pgprot_t vm_page_prot; /* Access permissions of this VMA. */
- unsigned long vm_flags; /* Flags, see mm.h. */
-
struct rb_node vm_rb;
/*
@@ -245,6 +243,12 @@ struct vm_area_struct {
*/
unsigned long rb_subtree_gap;
+ /* Second cache line starts here. */
+
+ struct mm_struct * vm_mm; /* The address space we belong to. */
+ pgprot_t vm_page_prot; /* Access permissions of this VMA. */
+ unsigned long vm_flags; /* Flags, see mm.h. */
+
/*
* For areas with an address space and backing store,
* linkage into the address_space->i_mmap interval tree, or
--
1.7.7.3
--
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next prev parent reply other threads:[~2012-11-05 22:47 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-05 22:46 [PATCH 00/16] mm: use augmented rbtrees for finding unmapped areas Michel Lespinasse
2012-11-05 22:46 ` [PATCH 01/16] mm: add anon_vma_lock to validate_mm() Michel Lespinasse
2012-11-05 23:06 ` Rik van Riel
2012-11-06 8:00 ` Michel Lespinasse
2012-11-05 22:46 ` [PATCH 02/16] mm: augment vma rbtree with rb_subtree_gap Michel Lespinasse
2012-11-05 22:47 ` [PATCH 03/16] mm: check rb_subtree_gap correctness Michel Lespinasse
2012-11-06 22:38 ` Andrew Morton
2012-11-09 14:13 ` Sasha Levin
2012-11-09 20:06 ` Hugh Dickins
2012-11-12 11:55 ` Michel Lespinasse
2012-11-05 22:47 ` Michel Lespinasse [this message]
2012-11-05 22:47 ` [PATCH 05/16] mm: vm_unmapped_area() lookup function Michel Lespinasse
2012-11-05 22:47 ` [PATCH 06/16] mm: use vm_unmapped_area() on x86_64 architecture Michel Lespinasse
2012-11-05 22:47 ` [PATCH 07/16] mm: fix cache coloring " Michel Lespinasse
2012-11-06 22:38 ` Andrew Morton
2012-11-05 22:47 ` [PATCH 08/16] mm: use vm_unmapped_area() in hugetlbfs Michel Lespinasse
2012-11-05 23:33 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 09/16] mm: use vm_unmapped_area() in hugetlbfs on i386 architecture Michel Lespinasse
2012-11-05 23:07 ` Rik van Riel
2012-11-06 22:38 ` Andrew Morton
2012-11-06 22:48 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 10/16] mm: use vm_unmapped_area() on mips architecture Michel Lespinasse
2012-11-05 23:34 ` Rik van Riel
2012-11-06 22:38 ` Andrew Morton
2012-11-05 22:47 ` [PATCH 11/16] mm: use vm_unmapped_area() on arm architecture Michel Lespinasse
2012-11-05 23:35 ` Rik van Riel
2012-11-06 22:38 ` Andrew Morton
2012-11-05 22:47 ` [PATCH 12/16] mm: use vm_unmapped_area() on sh architecture Michel Lespinasse
2012-11-05 23:35 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 13/16] mm: use vm_unmapped_area() on sparc64 architecture Michel Lespinasse
2012-11-05 23:36 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 14/16] mm: use vm_unmapped_area() in hugetlbfs " Michel Lespinasse
2012-11-05 23:36 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 15/16] mm: use vm_unmapped_area() on sparc32 architecture Michel Lespinasse
2012-11-05 23:37 ` Rik van Riel
2012-11-06 1:25 ` David Miller
2012-11-06 3:13 ` Michel Lespinasse
2012-11-06 7:30 ` Rik van Riel
2012-11-06 17:41 ` David Miller
2012-11-05 22:47 ` [PATCH 16/16] mm: use vm_unmapped_area() in hugetlbfs on tile architecture Michel Lespinasse
2012-11-05 23:37 ` Rik van Riel
2012-11-06 22:11 ` [PATCH 00/16] mm: use augmented rbtrees for finding unmapped areas Andrew Morton
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