On Wednesday 09 March 2011 19:20:38 Philippe De Muyter wrote:
On Wed, Mar 09, 2011 at 06:45:41PM +0100, Philippe De Muyter wrote:
Hello Arnd,
flashbench -s --scatter-span=3 --scatter-order=14 --blocksize=8192 --count=100 /dev/sdb -o output.plot
I did that, but the output.plot file is empty :(
I tried to reproduce it here, and accidentally pasted the '>' from the email into the command line, which resulted in bash overwriting the flashbench command with an empty shell script. Maybe you did the same? Deleting and rebuilding flashbench fixed it here.
No, here flashbench runs and creates output.plot if it does not exist before, but does not write anything into it.
I'll look into the sources to see what happens.
OK, the culprit is
returnif (time);in try_scatter_io.
I have printed the values of time, and I get a range of similar values, followed by a negative value :(
... time = 4230719 time = 4233873 time = 4230636 time = -4290735028
At that point try_scatter_io returns without ouputting anything.
Ah, thanks.
I should really commit all the patches I got. Someone else reported this earlier, but it only happens on ARM systems, which are 32 bit. PCs are normally 64 bit, so the type conversion problem does not happen.
I've uploaded the fix now.
Arnd