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authorVladimir Davydov <vdavydov@parallels.com>2014-08-08 14:21:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-08 15:57:23 -0700
commitce65cefa5debefc0e81d0a533bda467f0aa67350 (patch)
tree326946387f9add11f607bea19b2f8367de348e8e /kernel
parent41f727fde1fe40efeb4fef6fdce74ff794be5aeb (diff)
fork: reset mm->pinned_vm
mm->pinned_vm counts pages of mm's address space that were permanently pinned in memory by increasing their reference counter. The counter was introduced by commit bc3e53f682d9 ("mm: distinguish between mlocked and pinned pages"), while before it locked_vm had been used for such pages. Obviously, we should reset the counter on fork if !CLONE_VM, just like we do with locked_vm, but currently we don't. Let's fix it. This patch will fix the contents of /proc/pid/status:VmPin. ib_umem_get[infiniband] and perf_mmap still check pinned_vm against RLIMIT_MEMLOCK. It's left from the times when pinned pages were accounted under locked_vm, but today it looks wrong. It isn't clear how we should deal with it. We still have some drivers accounting pinned pages under mm->locked_vm - this is what commit bc3e53f682d9 was fighting against. It's infiniband/usnic and vfio. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Roland Dreier <roland@kernel.org> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.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/fork.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 418b52a9ec6a..5a547a59a38a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -543,6 +543,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
atomic_long_set(&mm->nr_ptes, 0);
mm->map_count = 0;
mm->locked_vm = 0;
+ mm->pinned_vm = 0;
memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
spin_lock_init(&mm->page_table_lock);
mm_init_cpumask(mm);