From: Christoph Hellwig <hch@lst.de>
To: rusty@rustcorp.com.au
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: [PATCH] virtio_blk: don't bounce highmem requests
Date: Fri, 19 Jun 2009 20:20:22 +0200 [thread overview]
Message-ID: <20090619182022.GA10999@lst.de> (raw)
By default a block driver bounces highmem requests, but virtio-blk is
perfectly fine with any request that fit into it's 64 bit addressing scheme,
mapped in the kernel virtual space or not.
Besides improving performance on highmem systems this also makes the
reproducible oops in __bounce_end_io go away (but hiding the real cause).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Index: linux-2.6/drivers/block/virtio_blk.c
===================================================================
--- linux-2.6.orig/drivers/block/virtio_blk.c 2009-06-15 16:28:24.225815322 +0200
+++ linux-2.6/drivers/block/virtio_blk.c 2009-06-19 18:03:12.469805377 +0200
@@ -360,6 +360,9 @@ static int __devinit virtblk_probe(struc
blk_queue_max_phys_segments(vblk->disk->queue, vblk->sg_elems-2);
blk_queue_max_hw_segments(vblk->disk->queue, vblk->sg_elems-2);
+ /* No need to bounce any requests */
+ blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
+
/* No real sector limit. */
blk_queue_max_sectors(vblk->disk->queue, -1U);
next reply other threads:[~2009-06-19 18:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-19 18:20 Christoph Hellwig [this message]
2009-06-20 18:32 ` [PATCH] virtio_blk: don't bounce highmem requests Christoph Hellwig
2009-06-23 7:12 ` Rusty Russell
2009-07-08 18:10 ` Christoph Hellwig
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