sched, net: Clean up preempt_enable_no_resched() abuse

The only valid use of preempt_enable_no_resched() is if the very next
line is schedule() or if we know preemption cannot actually be enabled
by that statement due to known more preempt_count 'refs'.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: rjw@rjwysocki.net
Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: rui.zhang@intel.com
Cc: jacob.jun.pan@linux.intel.com
Cc: Mike Galbraith <bitbucket@online.de>
Cc: hpa@zytor.com
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: lenb@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131119151338.GF3694@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c4638e6..82de786 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1623,11 +1623,11 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                    (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
                    !sysctl_tcp_low_latency &&
                    net_dma_find_channel()) {
-                       preempt_enable_no_resched();
+                       preempt_enable();
                        tp->ucopy.pinned_list =
                                        dma_pin_iovec_pages(msg->msg_iov, len);
                } else {
-                       preempt_enable_no_resched();
+                       preempt_enable();
                }
        }
 #endif