4.10 Approaching

Chris Johns chrisj at rtems.org
Fri Oct 2 01:50:38 UTC 2009

Till Straumann wrote:
> I actually would really recommend the HAVE_BLKSIZE patch - which
> BTW has been recommended for a looong time; see e.g.,
> libfs/src/nfsclient/README. It greatly improves stdio on any blocked 
> filsystem.
> msdosfs and NFS already do provide the necessary blocksize information.
> IMFS currently sets the blocksize to 0 for directories. zero is also
> the default if a filesystem does not set/provide a blocksize.
> newlib stdio correctly handles the case of a zero blocksize but
> some 'fseek()' performance gain could be achieved by using
> BUFSIZ/1024 in these cases.
> I can't really see *anything* controversial in this case.

I have just looked in my local copy of newlib-1.17.0 and ChangeLog.rtems 

2009-02-24      Ralf Corsépius <ralf.corsepius at rtems.org>

         * libc/unix/ttyname.c: Sync with newlib-cvs.
         * configure.host: Add -DHAVE_BLKSIZE to newlib_cflags.

Is this change already in newlib ? I cannot remember if I applied any of 
Ralf's patches to this or if they are clean. I seem to remember them 
being clean.

FYI I have code I am working on that allows the block size to change at 
the bdbuf layer and below. Currently the coming RFS file system has 
support for changing the block size. The MSDOS file system could be 
changed to do this and so removed the way it handles the buffers. Along 
with this change I have a statvfs call to add to libcsupport. The call 
returns the file system block and the media block sizes.


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