mm: change anon_vma linking to fix multi-process server scalability issue

[safe/jmp/linux-2.6] / kernel / relay.c

diff --git a/kernel/relay.c b/kernel/relay.c
index 824b91a..c705a41 100644 (file)
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -60,7 +60,7 @@ static int relay_buf_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 /*
  * vm_ops for relay file mappings.
  */
-static struct vm_operations_struct relay_file_mmap_ops = {
+static const struct vm_operations_struct relay_file_mmap_ops = {
        .fault = relay_buf_fault,
        .close = relay_file_mmap_close,
 };
@@ -795,13 +795,15 @@ void relay_subbufs_consumed(struct rchan *chan,
        if (!chan)
                return;
 
-       if (cpu >= NR_CPUS || !chan->buf[cpu])
+       if (cpu >= NR_CPUS || !chan->buf[cpu] ||
+                                       subbufs_consumed > chan->n_subbufs)
                return;
 
        buf = chan->buf[cpu];
-       buf->subbufs_consumed += subbufs_consumed;
-       if (buf->subbufs_consumed > buf->subbufs_produced)
+       if (subbufs_consumed > buf->subbufs_produced - buf->subbufs_consumed)
                buf->subbufs_consumed = buf->subbufs_produced;
+       else
+               buf->subbufs_consumed += subbufs_consumed;
 }
 EXPORT_SYMBOL_GPL(relay_subbufs_consumed);
 
@@ -1196,7 +1198,7 @@ static void relay_pipe_buf_release(struct pipe_inode_info *pipe,
        relay_consume_bytes(rbuf, buf->private);
 }
 
-static struct pipe_buf_operations relay_pipe_buf_ops = {
+static const struct pipe_buf_operations relay_pipe_buf_ops = {
        .can_merge = 0,
        .map = generic_pipe_buf_map,
        .unmap = generic_pipe_buf_unmap,