The patch titled
mm: move use_mm/unuse_mm from aio.c to mm/
has been added to the -mm tree. Its filename is
mm-move-use_mm-unuse_mm-from-aioc-to-mm.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mm: move use_mm/unuse_mm from aio.c to mm/
From: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Anyone who wants to do copy to/from user from a kernel thread, needs
use_mm (like what fs/aio has). Move that into mm/, to make reusing and
exporting easier down the line, and make aio use it. Next intended user,
besides aio, will be vhost-net.
Acked-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/aio.c | 47 -----------------------------
include/linux/mmu_context.h | 9 +++++
mm/Makefile | 2 -
mm/mmu_context.c | 55 ++++++++++++++++++++++++++++++++++
4 files changed, 66 insertions(+), 47 deletions(-)
diff -puN fs/aio.c~mm-move-use_mm-unuse_mm-from-aioc-to-mm fs/aio.c
--- a/fs/aio.c~mm-move-use_mm-unuse_mm-from-aioc-to-mm
+++ a/fs/aio.c
@@ -24,6 +24,7 @@
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/mman.h>
+#include <linux/mmu_context.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/aio.h>
@@ -34,7 +35,6 @@
#include <asm/kmap_types.h>
#include <asm/uaccess.h>
-#include <asm/mmu_context.h>
#if DEBUG > 1
#define dprintk printk
@@ -595,51 +595,6 @@ static struct kioctx *lookup_ioctx(unsig
}
/*
- * use_mm
- * Makes the calling kernel thread take on the specified
- * mm context.
- * Called by the retry thread execute retries within the
- * iocb issuer's mm context, so that copy_from/to_user
- * operations work seamlessly for aio.
- * (Note: this routine is intended to be called only
- * from a kernel thread context)
- */
-static void use_mm(struct mm_struct *mm)
-{
- struct mm_struct *active_mm;
- struct task_struct *tsk = current;
-
- task_lock(tsk);
- active_mm = tsk->active_mm;
- atomic_inc(&mm->mm_count);
- tsk->mm = mm;
- tsk->active_mm = mm;
- switch_mm(active_mm, mm, tsk);
- task_unlock(tsk);
-
- mmdrop(active_mm);
-}
-
-/*
- * unuse_mm
- * Reverses the effect of use_mm, i.e. releases the
- * specified mm context which was earlier taken on
- * by the calling kernel thread
- * (Note: this routine is intended to be called only
- * from a kernel thread context)
- */
-static void unuse_mm(struct mm_struct *mm)
-{
- struct task_struct *tsk = current;
-
- task_lock(tsk);
- tsk->mm = NULL;
- /* active_mm is still 'mm' */
- enter_lazy_tlb(mm, tsk);
- task_unlock(tsk);
-}
-
-/*
* Queue up a kiocb to be retried. Assumes that the kiocb
* has already been marked as kicked, and places it on
* the retry run list for the corresponding ioctx, if it
diff -puN /dev/null include/linux/mmu_context.h
--- /dev/null
+++ a/include/linux/mmu_context.h
@@ -0,0 +1,9 @@
+#ifndef _LINUX_MMU_CONTEXT_H
+#define _LINUX_MMU_CONTEXT_H
+
+struct mm_struct;
+
+void use_mm(struct mm_struct *mm);
+void unuse_mm(struct mm_struct *mm);
+
+#endif
diff -puN mm/Makefile~mm-move-use_mm-unuse_mm-from-aioc-to-mm mm/Makefile
--- a/mm/Makefile~mm-move-use_mm-unuse_mm-from-aioc-to-mm
+++ a/mm/Makefile
@@ -11,7 +11,7 @@ obj-y := bootmem.o filemap.o mempool.o
maccess.o page_alloc.o page-writeback.o \
readahead.o swap.o truncate.o vmscan.o shmem.o \
prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
- page_isolation.o mm_init.o $(mmu-y)
+ page_isolation.o mm_init.o mmu_context.o $(mmu-y)
obj-y += init-mm.o
obj-$(CONFIG_PROC_PAGE_MONITOR) += pagewalk.o
diff -puN /dev/null mm/mmu_context.c
--- /dev/null
+++ a/mm/mmu_context.c
@@ -0,0 +1,55 @@
+/* Copyright (C) 2009 Red Hat, Inc.
+ *
+ * See ../COPYING for licensing terms.
+ */
+
+#include <linux/mm.h>
+#include <linux/mmu_context.h>
+#include <linux/sched.h>
+
+#include <asm/mmu_context.h>
+
+/*
+ * use_mm
+ * Makes the calling kernel thread take on the specified
+ * mm context.
+ * Called by the retry thread execute retries within the
+ * iocb issuer's mm context, so that copy_from/to_user
+ * operations work seamlessly for aio.
+ * (Note: this routine is intended to be called only
+ * from a kernel thread context)
+ */
+void use_mm(struct mm_struct *mm)
+{
+ struct mm_struct *active_mm;
+ struct task_struct *tsk = current;
+
+ task_lock(tsk);
+ active_mm = tsk->active_mm;
+ atomic_inc(&mm->mm_count);
+ tsk->mm = mm;
+ tsk->active_mm = mm;
+ switch_mm(active_mm, mm, tsk);
+ task_unlock(tsk);
+
+ mmdrop(active_mm);
+}
+
+/*
+ * unuse_mm
+ * Reverses the effect of use_mm, i.e. releases the
+ * specified mm context which was earlier taken on
+ * by the calling kernel thread
+ * (Note: this routine is intended to be called only
+ * from a kernel thread context)
+ */
+void unuse_mm(struct mm_struct *mm)
+{
+ struct task_struct *tsk = current;
+
+ task_lock(tsk);
+ tsk->mm = NULL;
+ /* active_mm is still 'mm' */
+ enter_lazy_tlb(mm, tsk);
+ task_unlock(tsk);
+}
_
Patches currently in -mm which might be from mst@xxxxxxxxxx are
origin.patch
linux-next.patch
mm-move-use_mm-unuse_mm-from-aioc-to-mm.patch
mm-reduce-atomic-use-on-use_mm-fast-path.patch
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