Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-15 Thread Zhi Yong Wu
On Wed, Sep 14, 2011 at 10:17 PM, Stefan Hajnoczi wrote: > On Wed, Sep 14, 2011 at 3:42 AM, Zhi Yong Wu wrote: >> Log for bps=((10 * 1024 * 1024)). > > Okay, I think this data shows that I/O limits is too aggressive. > There seems to be some "overhead" amount so the guest is never able to > reach

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-14 Thread Stefan Hajnoczi
On Wed, Sep 14, 2011 at 3:42 AM, Zhi Yong Wu wrote: > Log for bps=((10 * 1024 * 1024)). Okay, I think this data shows that I/O limits is too aggressive. There seems to be some "overhead" amount so the guest is never able to reach its bps limit: > test: (g=0): rw=write, bs=64K-64K/64K-64K, ioengi

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-13 Thread Zhi Yong Wu
Log for bps=((10 * 1024 * 1024)). test: (g=0): rw=write, bs=512-512/512-512, ioengine=libaio, iodepth=1 Starting 1 process Jobs: 1 (f=1): [W] [100.0% done] [0K/58K /s] [0/114 iops] [eta 00m:00s] test: (groupid=0, jobs=1): err= 0: pid=2657 write: io=51,200KB, bw=58,527B/s, iops=114, runt=895793ms

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-13 Thread Zhi Yong Wu
On Tue, Sep 13, 2011 at 6:14 PM, Stefan Hajnoczi wrote: > On Tue, Sep 13, 2011 at 10:25 AM, Zhi Yong Wu wrote: >> On Tue, Sep 13, 2011 at 3:14 PM, Stefan Hajnoczi >> wrote: >>> On Tue, Sep 13, 2011 at 10:52:44AM +0800, Zhi Yong Wu wrote: This is real log when fio issued with bs=128K and bps

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-13 Thread Stefan Hajnoczi
On Tue, Sep 13, 2011 at 10:25 AM, Zhi Yong Wu wrote: > On Tue, Sep 13, 2011 at 3:14 PM, Stefan Hajnoczi > wrote: >> On Tue, Sep 13, 2011 at 10:52:44AM +0800, Zhi Yong Wu wrote: >>> This is real log when fio issued with bs=128K and bps=100(block >>> I/O throttling): >> >> I would use 1024 * 10

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-13 Thread Zhi Yong Wu
On Tue, Sep 13, 2011 at 3:14 PM, Stefan Hajnoczi wrote: > On Tue, Sep 13, 2011 at 10:52:44AM +0800, Zhi Yong Wu wrote: >> This is real log when fio issued with bs=128K and bps=100(block >> I/O throttling): > > I would use 1024 * 1024 instead of 100 as the throughput limit. > 10^5 is not a

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-13 Thread Zhi Yong Wu
On Tue, Sep 13, 2011 at 4:49 PM, Stefan Hajnoczi wrote: > On Tue, Sep 13, 2011 at 9:31 AM, Zhi Yong Wu wrote: >> On Tue, Sep 13, 2011 at 3:15 PM, Stefan Hajnoczi >> wrote: >>> On Tue, Sep 13, 2011 at 10:38:28AM +0800, Zhi Yong Wu wrote: On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-13 Thread Stefan Hajnoczi
On Tue, Sep 13, 2011 at 9:31 AM, Zhi Yong Wu wrote: > On Tue, Sep 13, 2011 at 3:15 PM, Stefan Hajnoczi > wrote: >> On Tue, Sep 13, 2011 at 10:38:28AM +0800, Zhi Yong Wu wrote: >>> On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi >>> wrote: >>> > On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-13 Thread Zhi Yong Wu
On Tue, Sep 13, 2011 at 3:15 PM, Stefan Hajnoczi wrote: > On Tue, Sep 13, 2011 at 10:38:28AM +0800, Zhi Yong Wu wrote: >> On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi >> wrote: >> > On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong Wu wrote: >> >> Today, i did some basical I/O testing, and su

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-13 Thread Stefan Hajnoczi
On Tue, Sep 13, 2011 at 10:38:28AM +0800, Zhi Yong Wu wrote: > On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi > wrote: > > On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong Wu wrote: > >> Today, i did some basical I/O testing, and suddenly found that qemu write > >> and rw speed is so low now,

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-13 Thread Stefan Hajnoczi
On Tue, Sep 13, 2011 at 10:52:44AM +0800, Zhi Yong Wu wrote: > This is real log when fio issued with bs=128K and bps=100(block > I/O throttling): I would use 1024 * 1024 instead of 100 as the throughput limit. 10^5 is not a multiple of 512 bytes and is not a nice value in KB/s (976.5625).

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-12 Thread Zhi Yong Wu
This is real log when fio issued with bs=128K and bps=100(block I/O throttling): 8,201 0.0 24332 A WS 79958528 + 256 <- (253,2) 71830016 8,002 0.00912 24332 A WS 80984576 + 256 <- (8,2) 79958528 8,203 0.01778 24332 Q W

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-12 Thread Zhi Yong Wu
On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi wrote: > On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong Wu wrote: >> Today, i did some basical I/O testing, and suddenly found that qemu write >> and rw speed is so low now, my qemu binary is built on commit >> 344eecf6995f4a0ad1d887cec922f6806

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-11 Thread Christoph Hellwig
On Fri, Sep 09, 2011 at 04:04:07PM +0200, Kevin Wolf wrote: > > need to read in the existing 4 KB, modify the 512 bytes in place, and > > write out the 4 KB block again. This is read-modify-write. In this > > worst-case scenario a 512 byte write turns into a 4 KB read followed > > by a 4 KB write

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-09 Thread Stefan Hajnoczi
On Fri, Sep 09, 2011 at 04:04:07PM +0200, Kevin Wolf wrote: > Am 09.09.2011 15:54, schrieb Stefan Hajnoczi: > > On Fri, Sep 9, 2011 at 2:48 PM, Zhi Yong Wu wrote: > >> On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi > >> wrote: > >>> On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong Wu wrote: >

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-09 Thread Zhi Yong Wu
On Fri, Sep 9, 2011 at 9:54 PM, Stefan Hajnoczi wrote: > On Fri, Sep 9, 2011 at 2:48 PM, Zhi Yong Wu wrote: >> On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi >> wrote: >>> On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong Wu wrote: Today, i did some basical I/O testing, and suddenly found

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-09 Thread Kevin Wolf
Am 09.09.2011 15:54, schrieb Stefan Hajnoczi: > On Fri, Sep 9, 2011 at 2:48 PM, Zhi Yong Wu wrote: >> On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi >> wrote: >>> On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong Wu wrote: Today, i did some basical I/O testing, and suddenly found that qemu

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-09 Thread Stefan Hajnoczi
On Fri, Sep 9, 2011 at 2:48 PM, Zhi Yong Wu wrote: > On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi > wrote: >> On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong Wu wrote: >>> Today, i did some basical I/O testing, and suddenly found that qemu write >>> and rw speed is so low now, my qemu bina

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-09 Thread Zhi Yong Wu
On Fri, Sep 9, 2011 at 6:38 PM, Stefan Hajnoczi wrote: > On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong Wu wrote: >> Today, i did some basical I/O testing, and suddenly found that qemu write >> and rw speed is so low now, my qemu binary is built on commit >> 344eecf6995f4a0ad1d887cec922f6806

Re: [Qemu-devel] Why qemu write/rw speed is so low?

2011-09-09 Thread Stefan Hajnoczi
On Fri, Sep 09, 2011 at 05:44:36PM +0800, Zhi Yong Wu wrote: > Today, i did some basical I/O testing, and suddenly found that qemu write and > rw speed is so low now, my qemu binary is built on commit > 344eecf6995f4a0ad1d887cec922f6806f91a3f8. > > Do qemu have regression? > > The testing data

[Qemu-devel] Why qemu write/rw speed is so low?

2011-09-09 Thread Zhi Yong Wu
HI, Today, i did some basical I/O testing, and suddenly found that qemu write and rw speed is so low now, my qemu binary is built on commit 344eecf6995f4a0ad1d887cec922f6806f91a3f8. Do qemu have regression? The testing data is shown as below: 1.) write test: (g=0): rw=write, bs=512-512/512-5