Re: Disk Performance Measurements

[Jens Axboe]

On Thu, May 03 2001, Shaun wrote:
> Again, this isn't the case in the 2.2.16 kernel I'm working with. Each
> call to make_request() causes pgin/pgout to be incremented, since these
> requests can be of different sizes (even for the same disk) I can't see
> how a kb value can be deduced. 

Check if the latest 2.2 is correct then, 2.4 is.

> Just as a question though, a disk/partition doesn't need to have a
> filesystem on it, so why is the "correct_size" for a buffer request on the
> block device defined based on a filesystem block system? 

It's not, but the fs may set the block size (ext2 does).

-- 
Jens Axboe