On Sep 18, 12:27am, juan@xtrarom.org (Juan RP) wrote:
-- Subject: Re: msdosfs: the fatblock() function is called many many times

| > Hi,
| > 
| > I just wanted to know why the msdosfs is so slow copying
| > large files (>500MB), and I tried to profile the kernel to
| > see the statistics:
| 
| Christos suggested me to inline the fatblock() function and
| run the test again.
| 
| The statistics with the inline function is here:
| 
| ftp://ftp.netbsd.org/pub/NetBSD/misc/xtraeme/gprof_msdosfs.txt
| 
| The fatblock() function disappeared from the stats, but the performance
| wasn't much better than before... <2MB/s writing to the msdosfs
| partition on my SATA drive:
| 
| wd0 at atabus0 drive 0: <Maxtor 6Y080M0>
| wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 6 (Ultra/133)

pcbmap is the problem... I will look into it.

christos