Re: 答复: journal alignment

2015-11-20 Thread Haomai Wang
On Fri, Nov 20, 2015 at 9:08 PM, Sage Weil wrote: > On Fri, 20 Nov 2015, Haomai Wang wrote: >> On Fri, Nov 20, 2015 at 7:41 PM, Sage Weil wrote: >> > On Fri, 20 Nov 2015, changtao381 wrote: >> >> Hi All, >> >> >> >> Thanks for you apply! >> >> >> >> If

Re: 答复: journal alignment

2015-11-20 Thread Haomai Wang
On Fri, Nov 20, 2015 at 7:41 PM, Sage Weil wrote: > On Fri, 20 Nov 2015, changtao381 wrote: >> Hi All, >> >> Thanks for you apply! >> >> If directioIO + async IO requirement that alignment, it shouldn't aligned by >> PAGE for each journal entry. >> For it may write many

Re: 答复: journal alignment

2015-11-20 Thread Evgeniy Firsov
Do you see any performance difference between direct io and non direct io mode? If it¹s disabled, you don¹t need any buffer alignment. On 11/20/15, 5:29 AM, "ceph-devel-ow...@vger.kernel.org on behalf of Haomai Wang" wrote: >On

答复: journal alignment

2015-11-20 Thread changtao381
Hi All, Thanks for you apply! If directioIO + async IO requirement that alignment, it shouldn't aligned by PAGE for each journal entry. For it may write many entries of journal once time So it should do alignment after [prepare_multi_write] rather than do it each in [prepare_single_write] ?

Re: 答复: journal alignment

2015-11-20 Thread 池信泽
Yes, You are right. But in ceph master branch, we have already prepare_entry(add padding) before sumibt_entry. If you have good idea base on this, It would be great. 2015-11-20 17:12 GMT+08:00 changtao381 : > Hi All, > > Thanks for you apply! > > If directioIO + async IO

Re: 答复: journal alignment

2015-11-20 Thread 池信泽
Because we should keep the logic of journal write thread simple. It performs better in pcie ssd. But I think the strategy you mentioned above is good for hdd or sata ssd. 2015-11-20 17:16 GMT+08:00 池信泽 : > Yes, You are right. But in ceph master branch, we have already >