xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mm/rmap: Convert the struct anon_vma::mutex to an rwsem

Browse Source 
Convert the struct anon_vma::mutex to an rwsem, which will help
in solving a page-migration scalability problem. (Addressed in
a separate patch.)

The conversion is simple and straightforward: in every case
where we mutex_lock()ed we'll now down_write().

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Turner <pjt@google.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
This commit is contained in:
Ingo Molnar
2012-12-02 19:56:46 +00:00
committed by Mel Gorman
parent d28d433512
commit 5a505085f0
4 changed files with 25 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
include/linux/rmap.h
View File

@@ -7,7 +7,7 @@
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/memcontrol.h>
/*
@@ -25,8 +25,8 @@
* pointing to this anon_vma once its vma list is empty.
*/
struct anon_vma {
struct anon_vma *root; /* Root of this anon_vma tree */
struct mutex mutex; /* Serialize access to vma list */
struct anon_vma *root; /* Root of this anon_vma tree */
struct rw_semaphore rwsem; /* W: modification, R: walking the list */
/*
* The refcount is taken on an anon_vma when there is no
* guarantee that the vma of page tables will exist for
@@ -64,7 +64,7 @@ struct anon_vma_chain {
struct vm_area_struct *vma;
struct anon_vma *anon_vma;
struct list_head same_vma; /* locked by mmap_sem & page_table_lock */
struct rb_node rb; /* locked by anon_vma->mutex */
struct rb_node rb; /* locked by anon_vma->rwsem */
unsigned long rb_subtree_last;
#ifdef CONFIG_DEBUG_VM_RB
unsigned long cached_vma_start, cached_vma_last;
@@ -108,24 +108,24 @@ static inline void vma_lock_anon_vma(struct vm_area_struct *vma)
{
struct anon_vma *anon_vma = vma->anon_vma;
if (anon_vma)
mutex_lock(&anon_vma->root->mutex);
down_write(&anon_vma->root->rwsem);
}
static inline void vma_unlock_anon_vma(struct vm_area_struct *vma)
{
struct anon_vma *anon_vma = vma->anon_vma;
if (anon_vma)
mutex_unlock(&anon_vma->root->mutex);
up_write(&anon_vma->root->rwsem);
}
static inline void anon_vma_lock(struct anon_vma *anon_vma)
{
mutex_lock(&anon_vma->root->mutex);
down_write(&anon_vma->root->rwsem);
}
static inline void anon_vma_unlock(struct anon_vma *anon_vma)
{
mutex_unlock(&anon_vma->root->mutex);
up_write(&anon_vma->root->rwsem);
}
/*