Hello Rusty, On Thu, May 29, 2014 at 04:56:41PM +0930, Rusty Russell wrote: > They don't make much difference: the easier fix is use gcc 4.8 > which drops stack required across virtio block's virtio_queue_rq > down to that kmalloc in virtio_ring from 528 to 392 bytes. > > Still, these (*lightly tested*) patches reduce to 432 bytes, > even for gcc 4.6.4. Posted here FYI. I am testing with below which was hack for Dave's idea so don't have a machine to test your patches until tomorrow. So, I will queue your patches into testing machine tomorrow morning. Thanks! diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f5c6635b806c..95f169e85dbe 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4241,10 +4241,13 @@ EXPORT_SYMBOL_GPL(yield_to); void __sched io_schedule(void) { struct rq *rq = raw_rq(); + struct blk_plug *plug = current->plug; delayacct_blkio_start(); atomic_inc(&rq->nr_iowait); - blk_flush_plug(current); + if (plug) + blk_flush_plug_list(plug, true); + current->in_iowait = 1; schedule(); current->in_iowait = 0; > > Cheers, > Rusty. > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>