From: Paolo Bonzini <pbonzini@redhat.com>
To: Ming Lei <ming.lei@canonical.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
Peter Maydell <peter.maydell@linaro.org>,
Fam Zheng <famz@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
qemu-devel <qemu-devel@nongnu.org>,
Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 01/15] qemu coroutine: support bypass mode
Date: Thu, 31 Jul 2014 18:30:24 +0200 [thread overview]
Message-ID: <53DA6F20.3050200@redhat.com> (raw)
In-Reply-To: <CACVXFVMsbu+VT9E0iLJ3_rX94MOr_rZaX8UPzQVPfyC5NK3T4g@mail.gmail.com>
Il 31/07/2014 18:13, Ming Lei ha scritto:
> Follows 'perf report' result on cycles event for with/without bypass
> coroutine:
>
> http://pastebin.com/ae0vnQ6V
>
> From the profiling result, looks bdrv_co_do_preadv() is a bit slow
> without bypass coroutine.
Yeah, I can count at least 3.3% time spent here:
0.87% bdrv_co_do_preadv
0.79% bdrv_aligned_preadv
0.71% qemu_coroutine_switch
0.52% tracked_request_begin
0.45% coroutine_swap
Another ~3% wasted in malloc, etc.
I suggest that we discuss it on the phone at next Tuesday's KVM call.
I'm not denying that bypassing coroutines is a useful thing to do. But
*everyone* should be doing that if it is so useful, and it's hard to do
it without causing code duplication.
Paolo
next prev parent reply other threads:[~2014-07-31 16:30 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-30 11:39 [Qemu-devel] [PATCH 00/14] dataplane: optimization and multi virtqueue support Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 01/15] qemu coroutine: support bypass mode Ming Lei
2014-07-30 13:45 ` Paolo Bonzini
2014-07-30 17:15 ` Ming Lei
2014-07-30 23:37 ` Paolo Bonzini
2014-07-31 3:55 ` Ming Lei
2014-07-31 7:37 ` Benoît Canet
2014-07-31 9:47 ` Ming Lei
2014-07-31 10:45 ` Paolo Bonzini
2014-08-01 13:38 ` Ming Lei
2014-07-31 8:59 ` Ming Lei
2014-07-31 9:15 ` Paolo Bonzini
2014-07-31 10:06 ` Ming Lei
2014-07-31 16:13 ` Ming Lei
2014-07-31 16:30 ` Paolo Bonzini [this message]
2014-08-01 2:54 ` Ming Lei
2014-08-01 13:13 ` Stefan Hajnoczi
2014-08-01 13:48 ` Ming Lei
2014-08-01 14:17 ` Paolo Bonzini
2014-08-01 15:21 ` Ming Lei
2014-08-01 14:52 ` Ming Lei
2014-08-01 16:03 ` Stefan Hajnoczi
2014-08-02 2:42 ` Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 02/15] qemu aio: prepare for supporting selective bypass coroutine Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 03/15] block: support to bypass qemu coroutinue Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 04/15] Revert "raw-posix: drop raw_get_aio_fd() since it is no longer used" Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 05/15] dataplane: enable selective bypassing coroutine Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 06/15] qemu/obj_pool.h: introduce object allocation pool Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 07/15] dataplane: use object pool to speed up allocation for virtio blk request Ming Lei
2014-07-30 14:14 ` Paolo Bonzini
2014-07-30 15:09 ` Michael S. Tsirkin
2014-07-31 3:22 ` Ming Lei
2014-07-31 9:18 ` Paolo Bonzini
2014-08-01 7:42 ` Ming Lei
2014-08-04 10:21 ` Stefan Hajnoczi
2014-08-04 11:42 ` Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 08/15] virtio: decrease size of VirtQueueElement Ming Lei
2014-07-30 13:51 ` Paolo Bonzini
2014-07-30 14:40 ` Michael S. Tsirkin
2014-07-30 14:50 ` Paolo Bonzini
2014-07-31 2:11 ` Ming Lei
2014-07-31 2:07 ` Ming Lei
2014-07-31 9:38 ` Paolo Bonzini
2014-08-01 3:34 ` Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 09/15] linux-aio: fix submit aio as a batch Ming Lei
2014-07-30 13:59 ` Paolo Bonzini
2014-07-30 17:32 ` Ming Lei
2014-07-30 23:41 ` Paolo Bonzini
2014-07-30 11:39 ` [Qemu-devel] [PATCH 10/15] linux-aio: increase max event to 256 Ming Lei
2014-07-30 12:15 ` Eric Blake
2014-07-30 14:00 ` Paolo Bonzini
2014-07-30 17:20 ` Ming Lei
2014-08-04 10:26 ` Stefan Hajnoczi
2014-07-30 11:39 ` [Qemu-devel] [PATCH 11/15] linux-aio: remove 'node' from 'struct qemu_laiocb' Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 12/15] hw/virtio-pci: introduce num_queues property Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 13/15] hw/virtio/virtio-blk.h: introduce VIRTIO_BLK_F_MQ Ming Lei
2014-07-30 11:39 ` [Qemu-devel] [PATCH 14/15] hw/block/virtio-blk: create num_queues vqs if dataplane is enabled Ming Lei
2014-07-30 14:01 ` Paolo Bonzini
2014-07-30 15:12 ` Michael S. Tsirkin
2014-07-30 15:25 ` Paolo Bonzini
2014-07-31 3:47 ` Ming Lei
2014-07-31 8:52 ` Paolo Bonzini
2014-08-01 3:09 ` Ming Lei
2014-08-01 3:24 ` Ming Lei
2014-08-01 6:10 ` Paolo Bonzini
2014-08-01 7:35 ` Ming Lei
2014-08-01 7:46 ` Paolo Bonzini
2014-07-30 11:39 ` [Qemu-devel] [PATCH 15/15] dataplane: virtio-blk: support mutlti virtqueue Ming Lei
2014-07-30 12:42 ` [Qemu-devel] [PATCH 00/14] dataplane: optimization and multi virtqueue support Christian Borntraeger
2014-08-04 10:16 ` Stefan Hajnoczi
2014-08-04 10:45 ` Ming Lei
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