Bram Stolk writes:
 > Hello,
 > 
 > I'm trying to delay the writes to disk.
 > 
 > Normally, this can be achieved by editting 
 > /proc/sys/vm/bdflush
 > 
 > I believed reiserfs does not use bdflush nor kupdated.
 > Looking at the source code, I get the impression that
 > the write delay is hard coded to 5 seconds.
 > Is this so?
 > 
 > The line of code that makes me think it is hardcoded
 > to 5 is this line:
 > 
 >     interruptible_sleep_on_timeout(&reiserfs_commit_thread_wait, 5) ;

Upgrade to the newer kernel, by the way: code line above contains bug
already fixed (interruptible_sleep_on_timeout() takes timeout in jiffies
rather than second). Back to the your question, there is no currently
way to tune this delay. I thought about reusing /proc/sys/vm/bdflush,
but this thing is not available to modules, as Chris Mason pointed
out. Probably our own parameter in /proc, or boot/module parameter is
the right way to go.

 > 
 > Is there an easy way to have the filesystem delay the writes much longer,
 > like an hour or so?

You will risk loosing a lot of data then, but if you want to do this,
just edit the code. It would be nice if you measured how this impacts
performance.

 > 
 > many thanks,
 > 
 >    Bram Stolk
 > 

Nikita.

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