Re: [PATCH] improve jbd fsync batching

[Ric Wheeler <rwheeler@redhat.com>]

Arjan van de Ven wrote:
> On Tue, 28 Oct 2008 15:38:05 -0600
> Andreas Dilger <adilger@sun.com> wrote:
>
>   
>> On Oct 28, 2008  16:16 -0400, Josef Bacik wrote:
>>     
>>> I also have a min() check in there to make sure we don't sleep
>>> longer than a jiffie in case our storage is super slow, this was
>>> requested by Andrew.
>>>       
>> Is there a particular reason why 1 jiffie is considered the "right
>> amount" of time to sleep, given this is a kernel config parameter and
>> has nothing to do with the storage?  Considering a seek time in the
>> range of ~10ms this would only be right for HZ=100 and the wait would
>>     
>
> well... my disk does a 50 usec seek time or so.. so I don't mind ;-)
>
> in fact it sounds awefully long to me.
>   

For small writes as well as reads?

If so, it would be great to test Josef's patch against your shiny new 
SSD  :-)

ric