From 71e20f1873d46e138c26ce83f8fe54b7221f572f Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 15 Oct 2007 17:00:19 +0200 Subject: sched: affine sync wakeups make sync wakeups affine for cache-cold tasks: if a cache-cold task is woken up by a sync wakeup then use the opportunity to migrate it straight away. (the two tasks are 'related' because they communicate) Signed-off-by: Ingo Molnar --- fs/pipe.c | 6 +++--- kernel/sched.c | 8 +++++++- net/unix/af_unix.c | 4 ++-- 3 files changed, 12 insertions(+), 6 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index f1fa2b412f0..e66ec48e95d 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -382,7 +382,7 @@ redo: /* Signal writers asynchronously that there is more room. */ if (do_wakeup) { - wake_up_interruptible(&pipe->wait); + wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } if (ret > 0) @@ -555,7 +555,7 @@ redo2: out: mutex_unlock(&inode->i_mutex); if (do_wakeup) { - wake_up_interruptible(&pipe->wait); + wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); } if (ret > 0) @@ -649,7 +649,7 @@ pipe_release(struct inode *inode, int decr, int decw) if (!pipe->readers && !pipe->writers) { free_pipe_info(inode); } else { - wake_up_interruptible(&pipe->wait); + wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } diff --git a/kernel/sched.c b/kernel/sched.c index 5a91fe0b5de..7fd34346259 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1521,6 +1521,12 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) unsigned long tl = this_load; unsigned long tl_per_task; + /* + * Attract cache-cold tasks on sync wakeups: + */ + if (sync && !task_hot(p, rq->clock, this_sd)) + goto out_set_cpu; + schedstat_inc(p, se.nr_wakeups_affine_attempts); tl_per_task = cpu_avg_load_per_task(this_cpu); @@ -1598,7 +1604,7 @@ out_activate: * the waker guarantees that the freshly woken up task is going * to be considered on this CPU.) */ - if (!sync || cpu != this_cpu) + if (!sync || rq->curr == rq->idle) check_preempt_curr(rq, p); success = 1; diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 2b57eaf66ab..6996cba5aa9 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -334,7 +334,7 @@ static void unix_write_space(struct sock *sk) read_lock(&sk->sk_callback_lock); if (unix_writable(sk)) { if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) - wake_up_interruptible(sk->sk_sleep); + wake_up_interruptible_sync(sk->sk_sleep); sk_wake_async(sk, 2, POLL_OUT); } read_unlock(&sk->sk_callback_lock); @@ -1639,7 +1639,7 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, if (!skb) goto out_unlock; - wake_up_interruptible(&u->peer_wait); + wake_up_interruptible_sync(&u->peer_wait); if (msg->msg_name) unix_copy_addr(msg, skb->sk); -- cgit v1.2.3