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From: Shaohua Li <shaohua.li@intel.com>
To: axboe@kernel.dk
Cc: linux-kernel@vger.kernel.org, vgoyal@redhat.com,
	david@fromorbit.com, jack@suse.cz, zhu.yanhai@gmail.com,
	namhyung.kim@lge.com, shaohua.li@intel.com
Subject: [patch v2 8/8]block: fiops sync preempts async
Date: Mon, 30 Jan 2012 15:02:21 +0800	[thread overview]
Message-ID: <20120130070635.412104517@sli10-conroe.sh.intel.com> (raw)
In-Reply-To: 20120130070213.793690895@sli10-conroe.sh.intel.com

[-- Attachment #1: fiops-preempt-async.patch --]
[-- Type: text/plain, Size: 963 bytes --]

Debug patch only.

This implements CFQ like sync preempts async. But like CFQ, this
will starve async.

---
 block/fiops-iosched.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

Index: linux/block/fiops-iosched.c
===================================================================
--- linux.orig/block/fiops-iosched.c	2012-01-21 10:35:04.000000000 +0800
+++ linux/block/fiops-iosched.c	2012-01-21 10:48:52.000000000 +0800
@@ -408,6 +408,21 @@ static struct fiops_ioc *fiops_select_io
 		return NULL;
 	}
 
+	/* Let sync request preempt async queue */
+	if (!rq_is_sync(rq) && service_tree->count > 1) {
+		struct rb_node *tmp = rb_next(&ioc->rb_node);
+		struct fiops_ioc *sync_ioc = NULL;
+		while (tmp) {
+			sync_ioc = rb_entry(tmp, struct fiops_ioc, rb_node);
+			rq = rq_entry_fifo(sync_ioc->fifo.next);
+			if (rq_is_sync(rq))
+				break;
+			tmp = rb_next(&sync_ioc->rb_node);
+		}
+		if (sync_ioc)
+			ioc = sync_ioc;
+	}
+
 	return ioc;
 }
 


  parent reply	other threads:[~2012-01-30  7:08 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-30  7:02 [patch v2 0/8]block: An IOPS based ioscheduler Shaohua Li
2012-01-30  7:02 ` [patch v2 1/8]block: fiops ioscheduler core Shaohua Li
2012-01-30  7:02 ` [patch v2 2/8]block: fiops read/write request scale Shaohua Li
2012-01-30  7:02 ` [patch v2 3/8]block: fiops sync/async scale Shaohua Li
2012-01-30  7:02 ` [patch v2 4/8]block: fiops add ioprio support Shaohua Li
2012-01-30  7:02 ` [patch v2 5/8]block: fiops preserve vios key for deep queue depth workload Shaohua Li
2012-01-30  7:02 ` [patch v2 6/8]block: fiops bias sync workload Shaohua Li
2012-01-30  7:02 ` [patch v2 7/8]block: fiops add some trace information Shaohua Li
2012-01-30  7:02 ` Shaohua Li [this message]
2012-01-30 11:53   ` [patch v2 8/8]block: fiops sync preempts async Hillf Danton
2012-01-30  7:09 ` [patch v2 0/8]block: An IOPS based ioscheduler Shaohua Li
2012-01-30 15:30 ` Vivek Goyal
2012-01-31  0:50   ` Shaohua Li

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