syncfs slower than without syncfs

syncfs slower than without syncfs

[Stefan Priebe - Profihost AG]

Hello list,

syncfs is much slower than without syncfs to me.

If i compile latest ceph master with wip-rbd-read:

with syncfs:
rand 4K:
   write: io=1133MB, bw=12853KB/s, iops=3213, runt= 90277msec
   read : io=1239MB, bw=14046KB/s, iops=3511, runt= 90325msec
seq 4M:
   write: io=37560MB, bw=423874KB/s, iops=103, runt= 90738msec
   read : io=103852MB, bw=1151MB/s, iops=287, runt= 90237msec

without syncfs:
rand 4K:
   write: io=3733MB, bw=42459KB/s, iops=10614, runt= 90039msec
   read : io=6018MB, bw=68446KB/s, iops=17111, runt= 90038msec
seq 4M:
   write: io=51204MB, bw=577328KB/s, iops=140, runt= 90820msec
   read : io=150320MB, bw=1666MB/s, iops=416, runt= 90228msec

I thought syncfs should boost the performance.

Greets,
Stefan

Re: syncfs slower than without syncfs

[Stefan Priebe - Profihost AG]

Am 07.11.2012 10:41, schrieb Stefan Priebe - Profihost AG:
> Hello list,
>
> syncfs is much slower than without syncfs to me.
>
> If i compile latest ceph master with wip-rbd-read:
>
> with syncfs:
> rand 4K:
>    write: io=1133MB, bw=12853KB/s, iops=3213, runt= 90277msec
>    read : io=1239MB, bw=14046KB/s, iops=3511, runt= 90325msec
> seq 4M:
>    write: io=37560MB, bw=423874KB/s, iops=103, runt= 90738msec
>    read : io=103852MB, bw=1151MB/s, iops=287, runt= 90237msec
>
> without syncfs:
> rand 4K:
>    write: io=3733MB, bw=42459KB/s, iops=10614, runt= 90039msec
>    read : io=6018MB, bw=68446KB/s, iops=17111, runt= 90038msec
> seq 4M:
>    write: io=51204MB, bw=577328KB/s, iops=140, runt= 90820msec
>    read : io=150320MB, bw=1666MB/s, iops=416, runt= 90228msec
>
> I thought syncfs should boost the performance.

Fixed - my chroot env with glibc syncfs support didn't had the libcrypto 
installed and it isn't in the control dependencies. Now with libcrypto i 
get the same results as without syncfs.

Stefan

Re: syncfs slower than without syncfs

[Mark Nelson]

Whew, glad you found the problem Stefan!  I was starting to wonder what 
was going on. :)  Do you mind filling a bug about the control dependencies?

Mark

On 11/07/2012 07:31 AM, Stefan Priebe - Profihost AG wrote:
> Am 07.11.2012 10:41, schrieb Stefan Priebe - Profihost AG:
>> Hello list,
>>
>> syncfs is much slower than without syncfs to me.
>>
>> If i compile latest ceph master with wip-rbd-read:
>>
>> with syncfs:
>> rand 4K:
>>    write: io=1133MB, bw=12853KB/s, iops=3213, runt= 90277msec
>>    read : io=1239MB, bw=14046KB/s, iops=3511, runt= 90325msec
>> seq 4M:
>>    write: io=37560MB, bw=423874KB/s, iops=103, runt= 90738msec
>>    read : io=103852MB, bw=1151MB/s, iops=287, runt= 90237msec
>>
>> without syncfs:
>> rand 4K:
>>    write: io=3733MB, bw=42459KB/s, iops=10614, runt= 90039msec
>>    read : io=6018MB, bw=68446KB/s, iops=17111, runt= 90038msec
>> seq 4M:
>>    write: io=51204MB, bw=577328KB/s, iops=140, runt= 90820msec
>>    read : io=150320MB, bw=1666MB/s, iops=416, runt= 90228msec
>>
>> I thought syncfs should boost the performance.
>
> Fixed - my chroot env with glibc syncfs support didn't had the libcrypto
> installed and it isn't in the control dependencies. Now with libcrypto i
> get the same results as without syncfs.
>
> Stefan
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Re: syncfs slower than without syncfs

[Stefan Priebe]

Am 07.11.2012 16:04, schrieb Mark Nelson:
> Whew, glad you found the problem Stefan!  I was starting to wonder what
> was going on. :)  Do you mind filling a bug about the control dependencies?

Sure where should i fill it in?

Stefan

Re: syncfs slower than without syncfs

[Josh Durgin]

On 11/07/2012 08:26 AM, Stefan Priebe wrote:
> Am 07.11.2012 16:04, schrieb Mark Nelson:
>> Whew, glad you found the problem Stefan!  I was starting to wonder what
>> was going on. :)  Do you mind filling a bug about the control
>> dependencies?
>
> Sure where should i fill it in?

http://www.tracker.newdream.net/projects/ceph/issues/new

Re: syncfs slower than without syncfs

[Stefan Priebe - Profihost AG]

done:
http://tracker.newdream.net/issues/3461
Am 08.11.2012 04:09, schrieb Josh Durgin:
> On 11/07/2012 08:26 AM, Stefan Priebe wrote:
>> Am 07.11.2012 16:04, schrieb Mark Nelson:
>>> Whew, glad you found the problem Stefan!  I was starting to wonder what
>>> was going on. :)  Do you mind filling a bug about the control
>>> dependencies?
>>
>> Sure where should i fill it in?
>
> http://www.tracker.newdream.net/projects/ceph/issues/new
>