From: Asias He <asias@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Sasha Levin <levinsasha928@gmail.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 3/3] virtio-blk: Add bio-based IO path for virtio-blk
Date: Tue, 03 Jul 2012 22:02:05 +0800 [thread overview]
Message-ID: <4FF2FB5D.5030102@redhat.com> (raw)
In-Reply-To: <4FF2F417.2010209@redhat.com>
On 07/03/2012 09:31 PM, Paolo Bonzini wrote:
> Il 02/07/2012 08:41, Rusty Russell ha scritto:
>>> With the same workload in guest, the guest fires 200K requests to host
>>> with merges enabled in guest (echo 0 > /sys/block/vdb/queue/nomerges),
>>> while the guest fires 40000K requests to host with merges disabled in
>>> guest (echo 2 > /sys/block/vdb/queue/nomerges). This show that the merge
>>> in block layer reduces the total number of requests fire to host a lot
>>> (40000K / 200K = 20).
>>>
>
> 40000 / 200 is 200, not 20. :)
Crap, I wrote one more zero here. Actually, it is 4000K. So the factor
is still 4000K/200k = 20 ;-)
--
Asias
WARNING: multiple messages have this Message-ID (diff)
From: Asias He <asias@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Sasha Levin <levinsasha928@gmail.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 3/3] virtio-blk: Add bio-based IO path for virtio-blk
Date: Tue, 03 Jul 2012 22:02:05 +0800 [thread overview]
Message-ID: <4FF2FB5D.5030102@redhat.com> (raw)
In-Reply-To: <4FF2F417.2010209@redhat.com>
On 07/03/2012 09:31 PM, Paolo Bonzini wrote:
> Il 02/07/2012 08:41, Rusty Russell ha scritto:
>>> With the same workload in guest, the guest fires 200K requests to host
>>> with merges enabled in guest (echo 0 > /sys/block/vdb/queue/nomerges),
>>> while the guest fires 40000K requests to host with merges disabled in
>>> guest (echo 2 > /sys/block/vdb/queue/nomerges). This show that the merge
>>> in block layer reduces the total number of requests fire to host a lot
>>> (40000K / 200K = 20).
>>>
>
> 40000 / 200 is 200, not 20. :)
Crap, I wrote one more zero here. Actually, it is 4000K. So the factor
is still 4000K/200k = 20 ;-)
--
Asias
next prev parent reply other threads:[~2012-07-03 14:02 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-18 6:53 [PATCH v2 0/3] Improve virtio-blk performance Asias He
2012-06-18 6:53 ` Asias He
2012-06-18 6:53 ` [PATCH 1/3] block: Introduce __blk_segment_map_sg() helper Asias He
2012-06-18 6:53 ` Asias He
2012-06-18 21:31 ` Tejun Heo
2012-06-18 21:31 ` Tejun Heo
2012-06-19 2:02 ` Asias He
2012-06-19 2:02 ` Asias He
2012-06-19 18:00 ` Tejun Heo
2012-06-19 18:00 ` Tejun Heo
2012-06-18 6:53 ` [PATCH v2 2/3] block: Add blk_bio_map_sg() helper Asias He
2012-06-18 6:53 ` Asias He
2012-06-18 6:53 ` [PATCH 3/3] virtio-blk: Add bio-based IO path for virtio-blk Asias He
2012-06-18 6:53 ` Asias He
2012-06-18 7:46 ` Rusty Russell
2012-06-18 7:46 ` Rusty Russell
2012-06-18 8:03 ` Asias He
2012-06-18 8:03 ` Asias He
2012-06-18 10:05 ` Rusty Russell
2012-06-18 10:05 ` Rusty Russell
2012-06-18 11:14 ` Dor Laor
2012-06-18 11:14 ` Dor Laor
2012-06-18 11:39 ` Sasha Levin
2012-06-18 11:39 ` Sasha Levin
2012-06-19 2:51 ` Asias He
2012-06-19 2:51 ` Asias He
2012-06-19 6:21 ` Dor Laor
2012-06-19 6:21 ` Dor Laor
2012-06-20 4:46 ` Asias He
2012-06-20 4:46 ` Asias He
2012-06-21 9:49 ` Dor Laor
2012-06-21 9:49 ` Dor Laor
2012-07-01 23:54 ` Rusty Russell
2012-07-01 23:54 ` Rusty Russell
2012-07-02 2:45 ` Asias He
2012-07-02 2:45 ` Asias He
2012-07-02 6:41 ` Rusty Russell
2012-07-02 6:41 ` Rusty Russell
2012-07-03 0:39 ` Asias He
2012-07-03 0:39 ` Asias He
2012-07-04 2:40 ` Rusty Russell
2012-07-04 2:40 ` Rusty Russell
2012-07-06 1:03 ` Asias He
2012-07-06 1:03 ` Asias He
2012-07-03 13:31 ` Paolo Bonzini
2012-07-03 13:31 ` Paolo Bonzini
2012-07-03 14:02 ` Asias He [this message]
2012-07-03 14:02 ` Asias He
2012-07-03 14:22 ` Ronen Hod
2012-07-03 14:22 ` Ronen Hod
2012-07-03 14:28 ` Dor Laor
2012-07-03 14:28 ` Dor Laor
2012-07-04 14:10 ` Paolo Bonzini
2012-07-04 14:10 ` Paolo Bonzini
2012-06-18 21:28 ` Tejun Heo
2012-06-18 21:28 ` Tejun Heo
2012-06-19 2:39 ` Asias He
2012-06-19 2:39 ` Asias He
2012-06-18 10:13 ` Michael S. Tsirkin
2012-06-18 10:13 ` Michael S. Tsirkin
2012-06-19 2:21 ` Asias He
2012-06-19 2:21 ` Asias He
2012-06-18 9:37 ` Stefan Hajnoczi
2012-06-18 9:37 ` Stefan Hajnoczi
2012-06-18 10:21 ` Michael S. Tsirkin
2012-06-18 10:21 ` Michael S. Tsirkin
2012-06-18 10:45 ` Stefan Hajnoczi
2012-06-18 10:45 ` Stefan Hajnoczi
2012-06-19 2:30 ` Asias He
2012-06-19 2:30 ` Asias He
2012-06-18 9:14 ` [PATCH v2 0/3] Improve virtio-blk performance Stefan Hajnoczi
2012-06-18 9:14 ` Stefan Hajnoczi
2012-06-18 9:39 ` Asias He
2012-06-18 9:39 ` Asias He
2012-06-18 10:58 ` Stefan Hajnoczi
2012-06-18 10:58 ` Stefan Hajnoczi
2012-06-19 4:24 ` Asias He
2012-06-19 4:24 ` Asias He
2012-06-19 10:14 ` Stefan Hajnoczi
2012-06-19 10:14 ` Stefan Hajnoczi
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