[patch] sched, net: fix scheduling latencies in __release_sock

Ingo Molnar
2004-09-14T11:03:59Z

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the attached patch fixes long scheduling latencies caused by backlog
triggered by __release_sock(). That code only executes in process
context, and we've made the backlog queue private already at this point
so it is safe to do a cond_resched_softirq().

This patch has been in the -VP patchset for some time.

Ingo

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the attached patch fixes long scheduling latencies caused by backlog
triggered by __release_sock(). That code only executes in process
context, and we've made the backlog queue private already at this point
so it is safe to do a cond_resched_softirq().

This patch has been in the -VP patchset for some time.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

--- linux/net/core/sock.c.orig
+++ linux/net/core/sock.c
@@ -933,6 +933,15 @@ void __release_sock(struct sock *sk)

skb->next = NULL;
sk->sk_backlog_rcv(sk, skb);
+
+ /*
+ * We are in process context here with softirqs
+ * disabled, use cond_resched_softirq() to preempt.
+ * This is safe to do because we've taken the backlog
+ * queue private:
+ */
+ cond_resched_softirq();
+
skb = next;
} while (skb != NULL);