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authorVegard Nossum <vegard.nossum@oracle.com>2017-02-27 14:30:07 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-27 18:43:48 -0800
commitf1f1007644ffc8051a4c11427d58b1967ae7b75a (patch)
treee7e590cb1baa494b963d81b967a3f98d3c56f33e /kernel
parent522b837c672eba9e9fb69f9f52bced0256dc6697 (diff)
downloadlinux-f1f1007644ffc8051a4c11427d58b1967ae7b75a.tar.gz
mm: add new mmgrab() helper
Apart from adding the helper function itself, the rest of the kernel is converted mechanically using: git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_count);/mmgrab\(\1\);/' git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_count);/mmgrab\(\&\1\);/' This is needed for a later patch that hooks into the helper, but might be a worthwhile cleanup on its own. (Michal Hocko provided most of the kerneldoc comment.) Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/exit.c2
-rw-r--r--kernel/futex.c2
-rw-r--r--kernel/sched/core.c4
3 files changed, 4 insertions, 4 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 90b09ca..8a768a3 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -539,7 +539,7 @@ static void exit_mm(void)
__set_current_state(TASK_RUNNING);
down_read(&mm->mmap_sem);
}
- atomic_inc(&mm->mm_count);
+ mmgrab(mm);
BUG_ON(mm != current->active_mm);
/* more a memory barrier than a real lock */
task_lock(current);
diff --git a/kernel/futex.c b/kernel/futex.c
index cdf3650..b687cb2 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -338,7 +338,7 @@ static inline bool should_fail_futex(bool fshared)
static inline void futex_get_mm(union futex_key *key)
{
- atomic_inc(&key->private.mm->mm_count);
+ mmgrab(key->private.mm);
/*
* Ensure futex_get_mm() implies a full barrier such that
* get_futex_key() implies a full barrier. This is relied upon
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index e1ae6ac..6ea1925 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2847,7 +2847,7 @@ context_switch(struct rq *rq, struct task_struct *prev,
if (!mm) {
next->active_mm = oldmm;
- atomic_inc(&oldmm->mm_count);
+ mmgrab(oldmm);
enter_lazy_tlb(oldmm, next);
} else
switch_mm_irqs_off(oldmm, mm, next);
@@ -6098,7 +6098,7 @@ void __init sched_init(void)
/*
* The boot idle thread does lazy MMU switching as well:
*/
- atomic_inc(&init_mm.mm_count);
+ mmgrab(&init_mm);
enter_lazy_tlb(&init_mm, current);
/*