Merge tag 'v3.12-rc5' into stable/for-linus-3.13

Linux 3.12-rc5

Because the Stefano branch (for SWIOTLB ARM changes) is based on that.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

* tag 'v3.12-rc5': (550 commits)
  Linux 3.12-rc5
  watchdog: sunxi: Fix section mismatch
  watchdog: kempld_wdt: Fix bit mask definition
  watchdog: ts72xx_wdt: locking bug in ioctl
  ARM: exynos: dts: Update 5250 arch timer node with clock frequency
  parisc: let probe_kernel_read() capture access to page zero
  parisc: optimize variable initialization in do_page_fault
  parisc: fix interruption handler to respect pagefault_disable()
  parisc: mark parisc_terminate() noreturn and cold.
  parisc: remove unused syscall_ipi() function.
  parisc: kill SMP single function call interrupt
  parisc: Export flush_cache_page() (needed by lustre)
  vfs: allow O_PATH file descriptors for fstatfs()
  ext4: fix memory leak in xattr
  ARC: Ignore ptrace SETREGSET request for synthetic register "stop_pc"
  ALSA: hda - Sony VAIO Pro 13 (haswell) now has a working headset jack
  ALSA: hda - Add a headset mic model for ALC269 and friends
  ALSA: hda - Fix microphone for Sony VAIO Pro 13 (Haswell model)
  compiler/gcc4: Add quirk for 'asm goto' miscompilation bug
  Revert "i915: Update VGA arbiter support for newer devices"
  ...

1 files changed, 11 insertions, 6 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 7c83cb8bf137..e6bb8256e59f 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -895,8 +895,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 
         skb_orphan(skb);
         skb->sk = sk;
-        skb->destructor = (sysctl_tcp_limit_output_bytes > 0) ?
-                          tcp_wfree : sock_wfree;
+        skb->destructor = tcp_wfree;
         atomic_add(skb->truesize, &sk->sk_wmem_alloc);
 
         /* Build TCP header and checksum it. */
@@ -1840,7 +1839,6 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
         while ((skb = tcp_send_head(sk))) {
                 unsigned int limit;
 
-
                 tso_segs = tcp_init_tso_segs(sk, skb, mss_now);
                 BUG_ON(!tso_segs);
 
@@ -1869,13 +1867,20 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
                                 break;
                 }
 
-                /* TSQ : sk_wmem_alloc accounts skb truesize,
-                 * including skb overhead. But thats OK.
+                /* TCP Small Queues :
+                 * Control number of packets in qdisc/devices to two packets / or ~1 ms.
+                 * This allows for :
+                 *  - better RTT estimation and ACK scheduling
+                 *  - faster recovery
+                 *  - high rates
                  */
-                if (atomic_read(&sk->sk_wmem_alloc) >= sysctl_tcp_limit_output_bytes) {
+                limit = max(skb->truesize, sk->sk_pacing_rate >> 10);
+
+                if (atomic_read(&sk->sk_wmem_alloc) > limit) {
                         set_bit(TSQ_THROTTLED, &tp->tsq_flags);
                         break;
                 }
+
                 limit = mss_now;
                 if (tso_segs > 1 && !tcp_urg_mode(tp))
                         limit = tcp_mss_split_point(sk, skb, mss_now,