[PATCH 05/15] sched, net: Clean up preempt_enable_no_resched() abuse

From: Peter Zijlstra
Date: Thu Dec 12 2013 - 09:24:39 EST


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'.

Cc: rjw@xxxxxxxxxxxxx
Cc: Eliezer Tamir <eliezer.tamir@xxxxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: rui.zhang@xxxxxxxxx
Cc: jacob.jun.pan@xxxxxxxxxxxxxxx
Cc: Mike Galbraith <bitbucket@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: hpa@xxxxxxxxx
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: lenb@xxxxxxxxxx
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
net/ipv4/tcp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1623,11 +1623,11 @@ int tcp_recvmsg(struct kiocb *iocb, stru
(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


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/